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What are Chinook Winds?

Posted on by Taylor Holmes

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn about their formation, effects, and more!

What is a Chinook?

Chinooks are strong, warm, dry, westerly winds that occur on the leeward side of the Rocky Mountains and cause sudden warming. Chinooks occur due to the geography of the Rockies themselves, and this phenomenon has wide ranging impacts on the ecosystems and people that call the foothills home.

Air currents, known as westerlies, carry moist air from the Pacific eastward into the continent’s interior. When this oceanic wind reaches the Rockies, the air is forced upwards and over the barrier. This process is known as orographic lift — from the Greek word for mountain, oros.

The air cools as it rises, causing moisture to condense into clouds and fall as precipitation on the windward side of the mountains. The now-dry air mass crests the mountain range, and travels down the leeward side of the mountains. As it descends, increasing atmospheric pressure compresses the air, which warms it.

This warm, dry, downslope wind is a Chinook.

Moist air currents from the Pacific Ocean blow inland and rise over the Rocky Mountains
Moisture condenses and falls as precipitation on the windward side.
The now dry air mass crests the mountain range and begins to descend the leeward side.
Compression warms the air mass. This warm, dry wind IS a chinook!

In some cases temperatures can rise by 25°C in a matter of hours due to chinooks, but how? According to the Canadian Encyclopedia, an increase of 27°C in two minutes has been observed during a chinook. Earlier in February, Canada experienced its first 20°C day of 2026 in Lethbridge, Alberta — this exceptionally warm winter weather was brought on by chinook winds.

 A few factors contribute to this stark spike in temperature:

  1. Water condensing on the windward side of the mountains returns latent heat to the air mass — though this only warms the air slightly.

  2. The downslope wind warms as it travels down the leeward side of the range. As chinook winds descend the eastern Rockies, the increase in atmospheric air pressure compresses the chinook air mass — causing it to warm quickly. This warming occurs adiabatically (see note below), and is the primary cause of warming during a chinook. 

  3. However, chinook winds in Alberta often replace cold arctic air that originates in the north, exacerbating temperature changes caused by chinooks.

Diabatic processes cause heating or cooling as the result of heat exchange from one source to another (such as the sun transferring heat to the Earth). In adiabatic processes, temperature change occurs without heat transfer due to the compression (heating) or expansion (cooling) of an air mass. 

Folklore

A group of Blackfoot people, ca. 1918

There is very little information available online regarding Indigenous folklore surrounding chinooks. The Blackfoot (Niitsitapi) are an Indigenous group that lives in the western Great Plains. One source claimed The Blackfoot word for chinooks translates to, “Snow-eater” — which they interpreted as a hot, dry and thirsty spirit that eats the snow.

However, I have been unable to find a copy of the film that this information is from to verify (The Snow Eater, 2003). If anyone knows where I can access this film, or knows Blackfoot folklore, please contact me.

Chinook Etymology

Chinookan traditional territories (yellow), located along the shores of the Pacific Ocean and Columbia River (in what is now Washington and Oregon, U.S.)

The word Chinook (shih-nook, /ʃɪˈnʊk/), originally pronounced Chinook (chi-nook, /tʃɪˈnʊk/), is the name of an Indigenous people who live near the Columbia river in the Pacific Northwest. This area experiences similarly gusty, warm winds, which French fur traders called Chinooks after the Indigenous people who lived in the region. Travelling with French fur-traders, the term was expanded to refer to the similar winds in the Columbia Plain and later the northwestern Great Plains.

Though I couldn’t find any source confirming, the change in pronunciation likely came from the French fur traders. The “ch-” or /tʃ/ sound doesn’t exist in French, so the pronunciation shifted to the “sh-” or /ʃ/ sound as a result of French influence.

While they use the same term, it’s worth noting that coastal and interior chinooks are caused by different processes — this article describes the process behind interior chinooks since those are what we get in Alberta.

Coastal chinooks (which are still pronounced ‘chi-nook’, or /tʃɪˈnʊk/) are warm, moist winds coming from the Pacific Ocean. Unlike interior chinooks, these winds bring with them abundant precipitation, which contributes to the climate of the Pacific Northwest and supports the regions temperate rainforests.

If you are curious and want to learn about some of the effects of coastal chinooks, I have a video that explores one of Canada’s temperate rainforests  in the Columbia mountains of British Columbia.

Related Articles

Global Occurrence

Chinooks occur regularly in the eastern Rockies and foothills of Alberta, Montana and Wyoming (weather Channel). They occur year-round, but are most pronounced in the winter when temperature fluctuations are more noticeable.

While the term Chinook is exclusive to western North America, the phenomenon behind them is not. Similar winds are found around the world — occurring where wind currents blow perpendicular to mountain ranges. As a rule, the taller and steeper the mountains, the more pronounced the effect.

A rotor cloud above the leeward slopes of the Antarctic Peninsula caused by Foehn winds (IMAGE: Depunity, 2011)

Similar winds from around the world:

  • Suêtes (Cape Breton Island, Nova Scotia, Canada)
  • Wreckhouse winds (Southwestern Newfoundland, Canada)
  • Santa Ana winds (Southern California, United States)
  • Mono winds (Sierra Nevada, California, United States)
  • Brookings Effect (Southwestern Oregon, United States)
  • Viento Zonda (Eastern Andes, Argentina)
  • Puelche winds (Chile)
  • Foehn/Föhn winds (European Alps)
  • Favonia (Ticino & northwest Italy)
  • Garbino (Adriatic coast, Italy)
  • Fønvind (south & central Norway)
  • Hnjúkaþeyr (Iceland)
  • Helm wind (Pennines, Cumbria, England)
  • Garmesh, Garmij, Garmbaad (Gilan Region, Iran)
  • Laos wind (north & central Vietnam)
  • Warm Braw (Schouten Islands, West Papua, Indonesia)
  • Nor’wester (Hawkes Bay, Canterbury, & Otago, New Zealand)
  • Great Dividing foehn (New South Wales, eastern Victoria, eastern Tasmania, Australia)
  • Bergwind (Great Escarpment, South Africa)
  • Föhn wall (Signy Island, South Orkneys, Antarctica)

All of these are caused by same combination of wind currents, orographic lift and adiabatic processes as interior Chinooks — they just go by different names. In many regions the term “foehn” has been borrowed and is used to describe regional winds. 

Effects on the Environment

Chinook winds have an array of effects on the environment.

Before they’re felt, their effects can often be seen. These winds are turbulent, and when the undulating air flows upwards, any remaining moisture condenses high in the atmosphere creating a cloud formation commonly referred to as a chinook arch.

These massive blankets of condensing water over the foothills are even visible from space.

A chinook arch (white box) is visible in this satellite image.

Chinook winds have an array of effects on the environment.

Before they’re felt, their effects can often be seen. These winds are turbulent, and when the undulating air flows upwards, any remaining moisture condenses high in the atmosphere at the crest of the rolling wave of wind. This creates a cloud formation commonly referred to as a chinook arch. These massive blankets of condensing water over the foothills are even visible from space.

In the alpine, Chinook winds redeposit fallen snow on leeward mountain ridges which can cause windslab avalanches. Slab avalanches are the most dangerous type of avalanche, and occur when snow accumulates and compacts forming a dense slab, which cleaves in massive sheets when snow layers aren’t adhered strongly.

Hot, dry chinook winds melt snow, desiccate plants, and dry and erode soil. It’s part of the reason why the eastern Rockies are so much drier than the western Rockies — though the rain-shadow effect also plays a role in the area’s aridity. Plants here are adapted to hot, dry, windy weather, and irrigation is vital for the region’s agriculture. Crop rotation is also utilized to help retain soil moisture and prevent wind erosion.

The high wind speeds brought by chinooks also make the Eastern Rockies a prime location for wind energy. Wind turbines can be spotted throughout southern Alberta, utilizing chinook winds to provide renewable energy to the regions populations.

Chinooks & Headaches

One interesting effect of chinooks is their association with headaches, migraines and other health issues. A study from the University of Calgary published in 2000 found that chinook winds increase the likelihood of migraines in some people. Though there was only an association between chinooks and migraines in half of the 75 individuals who took part in the study.

Scientists think that changes in barometric pressure from chinooks play a role in causing migraines. However, the results from studies are mixed. More research is needed to bolster the link between chinooks and headaches and determine a cause. Anecdotally, I do experience headaches and ear pain on windy chinook days, but cannot say if that’s caused by pressure changes, blowing winds, or some other factor.

There was also a retroactive study conducted in southern Bavaria which experiences similar foehn winds, which linked the foehns with increased risk of traumatic injury.

  1. Nkemdirim, L.C. (2024). “Chinook.” The Canadian Encyclopedia. Accessed via https://www.thecanadianencyclopedia.ca/en/article/chinook

  2. Gray, J. (2026). “Weather Words: Chinook Winds.” The Weather Channel. Accessed via https://weather.com/science/weather-explainers/news/2026-01-13-weather-words-chinook-winds

  3. Karami, S. (2025). “Explaining the science behind the warmth and the chaos of Calgary’s Chinook winds.” The Calgary Journal. accessed via https://calgaryjournal.ca/2025/03/04/explaining-the-science-behind-the-warmth-and-the-chaos-of-calgarys-chinook-winds/

  4. “Orographic Lift.” (N.D.). Modern Physics. Accessed via https://modern-physics.org/orographic-lifting/

  5. West, G. & Howard, R. (2019). “UBC ATSC 113 — 6e Orographic Lift & Lee Shadowing.” University of British Columbia — Department of Earth, Ocean and Atmospheric Sciences. Accessed via https://www.eoas.ubc.ca/courses/atsc113/snow/met_concepts/06-met_concepts/06e-orographic-uplift-lee-shadowing/

  6. CTV Your Morning (2018). “What is a chinook? | Ask Our Meteorologist.” YouTube. Accessed via https://www.youtube.com/watch?v=ak3OJZzlo-E&t=10s

  7. “The Chinook Wind.” (1940). Oregon Historical Quarterly, volume 41, no. 1. Accessed via https://www.jstor.org/stable/20611244

  8. Stone, L. (2024). “Chinook Winds, Explained.” Open Snow. Accessed via https://opensnow.com/news/post/chinook-winds-explained

  9. Grotjahn, R. (2003). “Diabatic Process.” Science Direct. Accessed via https://www.sciencedirect.com/topics/earth-and-planetary-sciences/diabatic-process

  10. “NOAA’s National Weather Service — Glossary.” (N.D.). NOAA. Accessed via https://forecast.weather.gov/glossary.php?word=adiabatic

  11. “Defining The Adiabatic Process — What It Is And How It Occurs.” (N.D.). Own Your Weather. Accessed via https://ownyourweather.com/adiabatic-process/

  12. “Explaining Chinook And Foehn Winds And How They are Formed.” (N.D.). Own Your Weather. Accessed via https://ownyourweather.com/chinook-and-foehn-winds/

  13. “We officially hit 20 C in Canada Wednesday. Here’s where.” (2026). The Weather Network. Accessed via https://www.theweathernetwork.com/en/news/weather/forecasts/we-officially-hit-20-c-in-canada-today-heres-where

  14. “Wind Slab.”(N.D.). National Avalanche Center. Accessed via https://avalanche.org/avalanche-encyclopedia/avalanche/avalanche-problems/avalanche-problem-type/wind-slab/

  15. “Slab.” (N.D.). National Avalanche Center. Accessed via https://avalanche.org/avalanche-encyclopedia/snowpack/slab/

  16. Said, A. (2025). “What’s the science behind chinook headaches? Experts still aren’t sure.” CBC Calgary. Accessed via https://www.cbc.ca/news/canada/calgary/chinook-winds-migraine-9.7015102

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What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

Read More »
Category: Nature

Backyard Friends: Black-capped Chickadee

Posted on by Taylor Holmes
The Backyard Friends is a series about animal pals that you might find in your backyard. No matter where we are, we are a part of the nature, not apart from it. 

Table of Contents

Overview

Scientific name: Poecile atricapillus

Common name(s): Black-capped Chickadee, Carbonero Cabecinegro (Spanish), Mésange à Tête noire (French).

Conservation Status: Least Concern (Population Decreasing)

Range: Canada (Except Nunavut and Labrador). American Northwest, Midwest, and Northeast.

Etymology

Black-capped chickadees’ name comes from the distinctive black plumage on their head, which gives the appearance that these birds hare wearing a little black cap.

Chickadees broadly are named after one of their most recognizable calls, which sounds like, “chickadee-dee-dee.”

Fun Fact: This "chickadee" song is actually a warning call. The more "-dee" notes sung, the greater the threat level.

In French these birds are known as Mésange à tête noire (meaning black-headed chickadee/tit) and in Spanish they are called Carbonero Cabecinegro (meaning black-headed coal-tit).

Description

Black-capped chickadees are in the family Paridae, which includes chickadees, tits, and titmice. North American species in this family are known as chickadees, while their Eurasian and African counterparts are called tits/titmice.

These beloved backyard birds can be identified by their black ‘cap and bib’, grey back, whitish belly; and buff-coloured sides. There is little difference between males and females. Chickadees are about the size of a sparrow, with a wingspan between 15 and 20 centimetres; and weighing between 9 and 14 grams.

A Black-capped Chickadee in some willows. (CREDIT: Taylor Holmes)

Black-capped Chickadees look most similar to Carolina Chickadee (P. carolinensis). The two species are discerned mainly by range, though the two species hybridize in a narrow zone of the eastern United States. Lesley the Bird Nerd made a great video on how to tell the two species apart.

Genetically, the Black-capped Chickadee’s closest relative is the Mountain Chickadee (P. gambeli), which has a distinguishing white eyebrow.

Mountain Chickadee, which is the closest relative of the Black-capped Chickadee (CREDIT: Ron Knight, 2015)
Carolina Chickadee. Though very similar in appearance to the Black-capped Chickadee, there ranges have little overlap. (CREDIT: Dan Pancamo, 2011).

Habitat

These chickadees are found in deciduous and mixed forests, open woods, willow thickets, and cottonwood groves. These adaptable birds can live pretty much anywhere with trees, and are often found in human-modified habitats, including orchards, parks and urban areas.

Chickadees are not considered migratory. However, large groups of chickadees — usually juveniles — fly southward. These “irruptions” are generally not considered true migration, and rarely extend past the Chickadees typical range.

Nesting

Black-capped Chickadees nest in nest boxes and small cavities, and are typically found between 1.5 and 8 m high. Chickadees are known to use abandoned downy woodpecker cavities, or excavate their own cavities. Cavities are then filled with wood shavings, animal hair, feathers and moss.

Map showing the Black-capped chickadee's range in North America (CREDIT: Birds of the World)

Diet

Diet: Insectivorous

Chickadees are primarily insectivorous, with some plant matter. The proportion of insect to plant matter varies depending on season (detailed below).

If you are looking to attract chickadees to your feeders, they prefer sunflower seeds, peanut butter, peanuts, suet, and mealworms.

A Black-capped Chickadee at a bird feeder (CREDIT: Taylor Holmes)

Winter Diet

During the winter, about half of a chickadees diet comes from plant matter, and half from animal sources.

Plant sources: Seeds, berries.

Animal sources: Insects, spiders, suet, occasionally carrion.

Summer Diet

Insects and other arthropods comprise between 80-90 per cent of a Black-capped Chickadee’s diet during the breeding season. They eat larges quantities of insect eggs, larvae, and pupae.

Plant sources: Seeds, berries

Animal sources: Weevils, lice, sawflies, and spiders.

Interspecific Interactions

Predators

Chickadees have to be on the look out for hawks and Northern Shrike which are their primary predators. 

Owls, snakes, raccoons, weasels, chipmunks, opossums, mice, and squirrels are also known predators. Predators may find, enter and raid nests. Eggs and young birds are eaten, and adult females are sometimes killed on their nests. 

A squirrel spotted in Toronto, Canada (CREDIT: Taylor Holmes)

Behaviour

Chickadees are active, curious, and social birds. They are known to be very curious towards people and are often willing to land on an outstretched hand — a delightful experience every time.

Social order is determined by aggressiveness. Each bird is know to others in its flock by rank, with the most aggressive chickadees asserting dominance over the others. Chickadees assert themselves vocally and physically. During breeding season song contests between males can escalate to the point that two males, feet-locked, plummet to the ground together.

As a rule, males dominate over females, and adults dominate over juveniles. Higher social rank within a flock grants the individual better access to food and nesting sites, as well higher survival rates for offspring. 

Black-capped chickadees socialize with more than just themselves. Various birds will flock amongst chickadees, including woodpeckers, nuthatches and warblers. Black-capped chickadees associate so closely with other species that several species will respond to their warning calls.

Complex Communication

On the topic of their calls, chickadees have highly advance communication. With songs so complex they resemble language, chickadees are able to communicate information on the identity of other flocks, in addition to producing predator alarms and contact calls.

Food Caches

As the weather cools, black-capped chickadees start to hide seeds and other food items for the winter. Each item is placed in a different spot or cache. To remember thousands of caches, these fluffy friends have developed a brilliant adaptation!

Every autumn, old neurons in the chickadee’s brains die, effectively deleting the old memories with them. These neurons are replaced, allowing chickadees adapt to changes and learn new things despite their small brains.

Reproduction

Mating System: Monogamous

Black-capped chickadees are monogamous, and usually mate fore life (though extra-pair copulations do occur). They mate once a year, with breeding season lasting from April to early August.

Chickadees lay between one and 13 eggs, which are white with little reddish-brown spots. Eggs are incubated for 12-13 days before hatching. Chickadees are born with their eyes closed and are mostly featherless, but they grow up quickly. After about two weeks chicks are ready to leave the nest and learn to fly. By the time the chicks are six weeks old, they are largely independent.

Niches

Ecosystem Roles

Black-capped chickadees serve as one of nature’s exterminators. They eat large quantities of insects, along with their eggs, larvae and pupae — making them vital for healthy forests.

Economic Importance

Because Black-capped Chickadees eat so many insects, they are an important form of pest control for orchards, helping to reduce reliance on pesticides. 

Conservation

The IUCN classifies the Black-capped Chickadee as Least Concern

Threats

There are an estimated 43-million black-capped chickadees in the wild today, and the IUCN classifies the species as Least Concern in terms of conservation. Though like many North American species, chickadees populations are in slight decline.

Clearing forests for agriculture can increase the amount of forest edge — providing improved habitat for chickadees. However, since chickadees nest in tree cavities, they suffer when too much standing deadwood is cleared.

  1. “Black-capped Chickadee.” (N.D.). Cornell University — All About Birds. Accessed via https://www.allaboutbirds.org/guide/Black-capped_Chickadee/overview

  2. Foote, J. R., D. J. Mennill, L. M. Ratcliffe, and S. M. Smith. (2020). “Black-capped Chickadee — Poecile atricapillus.” Birds of the World. Accessed via https://birdsoftheworld.org/bow/species/bkcchi/cur/introduction

  3. Rutherford, C.A., Richardson, L., Panjabi, A., Martin, R. (2025). “Black-capped Chickadee Peocile Atricapillus Species Factsheet.” Birdlife International DataZone. Accessed via https://datazone.birdlife.org/species/factsheet/black-capped-chickadee-poecile-atricapillus

  4. “Black-capped Chickadee.” (2003). Hinterland Who’s Who. Accessed via https://www.hww.ca/wildlife/birds/black-capped-chickadee/

  5. BirdLife International. (2025). “Poecile atricapillus (Black-capped Chickadee).” The IUCN Red List of Threatened Species 2025. Accessed via https://www.iucnredlist.org/species/22711716/137666504

  6. Roof, J. (2011). “Parus atricapillus (black-capped chickadee).” Animal Diversity Web. Accessed via https://animaldiversity.org/accounts/Parus_atricapillus/

  7. Otter, K. (2007). “The Ecology and Behaviour of Chickadees and Titmice.” Oxford University Press. Accessed via https://web2.uwindsor.ca/courses/biology/dmennill/pubs/2007Otter131.pdf

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What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

Read More »
Category: Backyard FriendsNature

New Year Update!

Posted on by Taylor Holmes

We have started the new year, so I thought it would be a good time to give a little update on both my website and YouTube channel to this little community we’re building.

Thank you!

First and foremost I wanted to thank everyone who read my articles, watches my videos, or subscribes to my channel. In the grand scheme of the internet, I’m a small fish, but my channel has grown a lot this year compared to where it was and I couldn’t be more grateful to everyone who’s joined and engaged with my content. I love to read your points of view, and am always learning new things or getting new video inspiration from your comments. 

Thank you!

Website Update

For the last couple of months I’ve been redesigning my website and logos, which is now mostly complete (there may be a few small tweaks here and there). Some older pages will likely need to be updated manually to ensure the formatting is legible and tidy, so please bear with me.

Going forward, I aim to publish more regularly on this blog. Video production has always been a priority for me, as a result this website had somewhat stagnated until recently. Soon you’ll find extra content that had to be cut from videos and additional resources including printables, and more.

Stance on Generative AI

This is a point I wanted to make clear going into the new year given the massive rise of generative AI (gen AI) that’s occurred the last few years. 

The Yellow Bird does not use generative AI in the production of any of its content, nor will the Yellow Bird be adopting the use of generative AI.

Taylor

There are concerns with sustainability, ethics, and accuracy that disqualify its use in any of my projects. Images, music, and graphics are either made myself, or sourced from various royalty free and public domain sources (favourites include Wikimedia Commons, Pixabay, Pexels). When necessary and possible AI content is filtered out on these sites, and I do my to vet the photos/videos used to ensure authenticity.

That's all for now!

Thank you so much for joining me on these adventures exploring human and natural history.

Until next time, consider watching my latest vlog or reading one of my articles below.

Read More

What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn about their formation, effects, and

Read More »

New Year Update!

January 1, 2026 No Comments

We have started the new year, so I thought it would be a good time to give a little update on both my website and

Read More »
Category: Personal

Endorheic Lakes: The lakes that go nowhere

Posted on by Taylor Holmes

Most lakes go somewhere… Into a river, another lake, the ocean, something. However, some lakes feed no river, pour into no sea. These are endorheic lakes, but what does that mean? How do they form? What lives near them? Why are they important? and where does the water go?

Table of Contents

What is an Endorheic Basin?

Endorheic or terminal basins have no outflow, endo means ‘within’ and -rheic means ‘to flow’. Water within these regions will never reach the ocean. Instead water flows into an inland basin or depression where it accumulates.

The vocabulary does get a bit confusing. Endorheic water can refer to all the water within a basin, or the terminal water bodies. Furthermore, endorheic basins can have both exorheic and endorheic lakes. The Jordan Rift Valley in West Asia is an endorheic basin, terminating in the Dead Sea. However, the sea of Gallilee, which lies within the basin, is exorheic since it drains into the Dead Sea via the Jordan River. 

The Dead Sea coast as viewed from Jordan. (Image: Faris knight, 2013)

Here, endorheic basin refers to the entire drainage basin. Endorheic lake or sea will refer to terminal water bodies within these basins.

If this water system sounds odd, it’s because they kind of are. 97 per cent of the terrestrial water (water found on or under continents) is exorheic — ‘exo’ meaning ‘outside’. Runoff flows into streams, which flow into lakes, which flow into rivers, until eventually the water reaches the ocean.

Without an outflow, most water loss in endorheic lakes is due to evaporation, and to a lesser extent seepage. Endorheic lakes are often salty because water evaporates but minerals don’t. Over time salts and minerals accumulate and concentrate in the water. Endorheic lakes with freshwater usually have higher levels of groundwater seepage, drawing minerals out of the lake.

Salt accumulating on rocks along the coast of the Dead Sea, one of the saltiest water bodies in the world. (Image: Petar Milošević, 2023)

How do they form?

Water naturally flows downhill, and usually the furthest thing downhill is the ocean — so most water flows towards it. If the vast majority of the earth’s water is exorheic, what prevents water in endorheic basins from reaching the ocean? 

Most endorheic lakes are found in arid and semi-arid climates, or far inland. In dry regions there simply isn’t enough surface runoff to erode land barriers blocking routes to the ocean. These barriers prevent water bodies from flowing towards or draining into the ocean. Instead water collects in a low point inland, where a terminal lake forms. This is amplified the further inland you go. There needs to be enough water to reach the ocean which may be thousands of kilometres away.

Several systems that historically reached the ocean became endorheic as precipitation decreased. The Caspian Sea and Lake Chad are two examples which will be discussed later.

Endorheic lakes also form in regions that are below sea level. In these places the path to the ocean would require water to flow uphill. Instead of defying physics, water in these areas pools instead, creating an endorheic Lake.

Endorheic Lakes below sea level:

  • The Caspian Sea (Azerbaijan, Iran, Kazakhstan, Russia, Turkmenistan)
  • Dead Sea (Israel, Jordan, West Bank)
  • Lake Assal (Djibouti)
  • Lake Afdera and Lake Karum (Ethiopia)
  • Salton Sea and Badwater Basin (California, U.S.A.)
  • Laguna del Carbón (Argentina)
Lake Karum (also known as Lake Assale) in Ethiopia. (Image: Thomas Fuhrmann, 2019).

Why are they important?

A map showing major endorheic basins and lakes. Drainage basins are light grey, lakes are dark grey.

A quarter of earth’s continental area falls within endorheic basins, though they contain surprisingly little water. Less than three per cent of terrestrial water is in endorheic basins — about as much water as the Yangtze River discharges annually. This water scarcity in these regions underlines the importance of endorheic lakes and ecologically and socioeconomically.

In addition to providing an accessible form of water in many region, the presence of large endorheic water bodies provide vital ecosystem services.

Larger endorheic lakes and seas impact climate by moderating temperature, humidity and precipitation much like the ocean does in coastal regions. This helps stabilize continental climates which naturally experience extreme temperature fluctuations seasonally, which enables these regions to support more abundance and diversity of life. 

Inland seas and lakes form critical habitat for endemic and migratory species. These unique ecosystems also shape the cultures that inhabit them. They provide a source of water, food, transport and energy. Several empires were born along the shores of endorheic lakes. This includes the Mexica or Aztec Empire of what-is-now Mexico, and Kanem-Bornu empire of North-Central Africa.

Endorheic Water Bodies

It’s time to look at eight endorheic lakes around the world, their unique ecosystems, cultural significance, and economic importance.

Caspian Sea

  • Region: Central Asia
  • Nation(s): Azerbaijan, Iran, Kazakhstan, Russia, Turkmenistan
  • Climate: Moderate continental climate (North), warm continental climate (middle and South), subtropical (Southwest), desert (East)
  • Area: 371,000km²
  • Status: At-risk (water levels decreasing)
The Caspian Sea as seen from aboard the International Space Station.

The Caspian Sea in Central Asia is not only the largest endorheic lake, but the largest inland water body in the world by area. Located in Central Asia, five countries border the Caspian: Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan.

The drainage basin that feeds the Caspian Sea is roughly 3.6-million square kilometres — roughly two per cent of the world’s territory. One third of all inland water lies in the Caspian, with the Volga River being responsible for 80 per cent of inflow. The Ural, Terek, Sulak, Samur and Kura rivers also drain into the Caspian. Notably, the sea’s eastern shore lacks any permanent streams.

The Caspian was not always endorheic. Around 11 million years ago, The Caspian Sea drained into the ocean via the Sea of Azov, the Black Sea and the Mediterranean Sea. As tectonic plates and climate patterns shifted, the Caspian Sea was slowly cut off from the ocean, making it endorheic.

A map showing the present-day Caspian Sea (left) and how it looked during the Late Pleistocene (right)

As the name suggests, the Caspian Sea is saline, though only about a third as salty as the ocean on average. Unlike the ocean, however, the Caspian Sea’s salinity varies tremendously. While the average salinity is around 12.8 parts per thousand, that figure ranges from 1 part per thousand near the Volga outlet to a whopping 200 parts per thousand in the Kara-Bogaz-Gol — where intense evaporation occurs. 

The climate varies across the Caspian. The north has a moderate continental climate, the southwest has subtropical influences, and the eastern shore is desert.

Roughly 850 animal and more than 500 plant species live in or near the Caspian Sea. Some are found nowhere else in the world, like the endangered Caspian seal. 

A Caspian Seal (Phoca caspica). (Image: Aboutaleb Nadri, 2016)

The Caspian Seal is a small, earless seal and the only marine mammal found in the Caspian. These marine mammals live on sea ice that forms in the northern during the winter, and reside in the warmer, southern waters during the summer. Their diet changes throughout the year, but consists of a variety of fish, molluscs and other invertebrates. Predators include wolves and sea eagles which hunt pups along the shore. 

Humans are the primary cause of mortality for the Caspian Seal. In the 20th century, unsustainable hunting practices decimated Caspian seal populations until hunting quotas were introduced in the 1960s and 1970s. Nowadays, the seals are unintentionally caught as bycatch, primarily on illegal sturgeon fisheries. Additionally, commercial fishing, water pollution and invasive comb jellies have reduced food sources for these seals.

Fishing is a critical industry in the Caspian Sea, it’s abundant in herring, pike, perch, sprat, and sturgeon. Historically, sturgeon fished in the Caspian Sea produced the most and highest quality black caviar in the world, which comes from Beluga, Osetra, and Sevruga sturgeon. Iran and Russia were the primary producers in the Caspian, and the Russian city of Astrakhan remains the centre of caviar trade.

A fishing vessel in the Amiribad Port, Iran. (Image: Amir Ali Razzaghi, 2015)
Black caviar

Transport is another important industry on the Caspian Sea. Petroleum, wood, grain, cotton, rice and sulphate are all regularly carried across the Caspian. Major ports include Astrakhan and Makhachkala in Russia, Baku in Azerbaijan, Bandar-e Anzalī in Iran, Türkmenbashi in Turkmenistan, and Aqtaū in Kazakhstan.

Energy production is also important economically within the basin. Both petroleum and natural gas are produced in the Caspian basin, primarily in the southern portion of the sea. The rivers that feed the Caspian are diverted to irrigate crops, and dams were built to generate electricity.

However, these industries are not without their impacts. Without an outflow, pollutants from industry and agriculture concentrate in the Caspian Sea’s waters, threatening wildlife and fisheries. Diversion of water for irrigation and hydroelectricity have altered the water table.

Water levels were stable in the Caspian Sea between 1840-1940. Since then there has been an overall decline in water levels (with a brief increase between 1978-1995). This decline in water levels is mainly attributed to climate change along with the construction of dams, reservoirs, and canals.

Satellite image of the Caspian Sea's North shore in 2006.
Satellite image of the Caspian Sea's North shore in 2022.

Aral Sea

  • Region: Central Asia
  • Nation(s): Kazakhstan, Uzbekistan
  • Climate: Desert-Continental climate
  • Area: ~8321km² (2018). 68,000km² (1960)
  • Status: Critical (desiccated, water levels decreasing)
Satellite image of the Aral Sea. taken in 1985. The Sea has shrunk substantially since.

The Aral Sea was once the fourth largest freshwater lake in the world. Located on the border between Kazakhstan and Uzbekistan. The Aral Sea is a tragic example of how fragile endorheic systems are and how water mismanagement can lead to ecosystem collapse. 

The basin that feeds the Aral Sea has an area of more than 2-million square kilometres. Headwaters from the Pamir and Tian Shen mountains feed into the Syr Darya and Amu Darya rivers, which were responsible for most of the Aral Sea’s inflow.  

Historically the Aral Sea supported a diverse ecosystem, both within the sea and along its shores. The Aral was home to abundant fish, including the Aral Barbel, Aral Sturgeon and a unique subspecies of trout. Habitat along its shores, including marshes were home to black-winged stilts, Pallas’ sandgrouse, warblers and larks. Wolves, Persian gazelles, Saiga Antelopes roamed nearby.

The Saiga antelope can be found near what remains of the Aral Sea. (Image: Andrey Giljov, 2016 )

The rich ecosystems sustained by the Aral Sea were also crucial to locals living along its shore. Abundant fisheries provided a source of food and income.

Unfortunately, the Aral Sea no longer supports the abundance and diversity of life it once did. The Aral Sea has rapidly dried up since the mid-twentieth century. So what happened?

Drying of the Aral Sea from 2000 to 2009

Mismanagement of water resources within the Aral Basin ultimately led to its demise. In the 1960s the Soviet government began diverting water from the Amu Darya and Syr Darya rivers for irrigation, primarily cotton farming. Diversion of river water, paired with intensive groundwater extraction, drastically reduced inflow into the Aral Sea. 

Between 1975 and 2007, the Aral Sea shrunk by 75 per cent from its original size. The effects of this have been nothing short of catastrophic for both human and wildlife regionally. 

Communities in the region still grapple with the impacts of the lake’s disappearance. Fisheries and the communities that depended on them for survival collapsed as the Aral Sea dried and became increasingly saline. The loss also jeopardizes animal husbandry, which is not only important economically but culturally for the traditionally nomadic groups in the region. 

The loss of the Aral Sea has led to a severe water crisis in the region. The drying of the Aral Sea created what’s now known as the Aralkum desert. As water evaporated in the sea, salt, fertilizers and pesticides concentrated and contaminated the lakebed. Dust storms now blow harmful dust from the lakebed onto surrounding cropland and communities. When the dust settles, it contaminates water sources and farmer’s fields. The dust is also a public health hazard reportedly causing several health issues affecting respiratory and reproductive systems and causing tumours.

A sunk vessel in the Aralkum desert, once the lakebed of the Aral Sea. (Image: Adam Harangozó, 2018)

The disappearance of the Aral Sea also impacted the regions climate. Large water bodies have a moderating effect on climate, which is why coastal regions are typically more temperate than inland areas. The drying of the Aral removed this service, leading to colder winters and warmer, drier summers. 

There have been efforts to protect and restore what’s left of the Aral Sea. Kazakhstan finished building the Kok-Aral dike and dam in 2005. This dam seperates and prevents flow from the North Aral into the South Aral. As a result, water levels rose, salinity decreased, and allowed fisheries to rebound in the North.

The UN Development program partnered with Kazakhstan and Uzbekistan to plant salt and drought resistant trees around the Aral Sea in 2015. Afforestation can help to conserve water, decrease summer air temperatures, and moderate climate. 

A saxual tree (Haloxylon). These drought-resistant trees are native to the Aral Sea region and have been planted to help restore the Aral Sea. (Image: Максат79, 2024)

One of the biggest ongoing challenge in restoring the Aral Sea is agriculture. Ninety per cent of water consumption in Central Asia is used for irrigation. In the Aral Sea, cotton is the biggest crop, but grains like wheat, barley, and rye are also grown. Shifting production to less water-intensive crops, and using water-conscious farming practices like minimal tilling can help reduce demand for water too. 

Lake Natron

  • Region: East Africa
  • Nation(s): Tanzania, Kenya
  • Climate: Semi-arid tropical savannah
  • Area: 1040km²
  • Status: At-risk

In northern Tanzania lies Lake Natron, a lake of extremes. Natron is a soda lake, meaning it contains high quantities of dissolved sodium and carbonate. These dissolved minerals make Lake Natron alkaline, with a pH between 9 and 10.5 (some sources claimed as high as 12) depending on water levels, similar to that of ammonia. Water temperatures can exceed 40 degrees celsius.

Lake Natron lies in the East African Rift Valley. Here the earth’s crust is ripping itself apart. The region is full volcanic activity, which gives Lake Natron one of its defining features.

Ol Doinyo Lengai volcano. The name means "mountain of God" in the Maasai language (Maa). (Image: Sixtuskev, 2010)

South of the lake is the Ol Doinyo Lengai volcano. This volcano is the only source of natrocarbonatite lava in the world. Most volcanic lava is high in silica, but not Ol Doinyo Lengai’s lava. Carbonatite lava has low silica, and much higher levels of minerals like calcite and dolomite.

Rich in sodium and potassium carbonates, debris from Ol Doinyo Lengai’s wash into Lake Natron. As the water evaporates, these salts and minerals concentrate in the lake which is why this lake is so caustic.

The Ol Doinyo Lengai crater. (Image: Pedro Gonnet, 2007)

Sodium carbonate found in Lake Natron is also able to calcify animals that fall into the lake, preserving them like mummies (sodium carbonate was also used by Egyptians in mummification). 

Lake Natron’s alkalinity and temperatures may lead one to think the lake is inhospitable, but it’s precisely these conditions that give the lake life.

The bright red colour in the lake comes from cyanobacteria that live in the water. Adapted to such a harsh environment, these bacteria provide a crucial food source for the lesser flamingo. The carotenoid pigments in these cyanobacteria are also responsible for making the flamingos pink!

Lake Natron is the only regular breeding ground for the near-threatened Lesser Flamingo (Phoeniconaias minor). The lake provides a source of food for the flamingos, and its caustic waters protect their nests and hatchlings from predators. 

A lesser flamingo (Pheoniconaias minor)

Once every few years when water levels are just right, more than 2 million lesser flamingos descend upon Lake Natron to breed, three-quarters of the world’s population. It is East Africa’s only regular breeding site for Lesser flamingos, making Lake Natron a critical area for conservation.

If Lake Natron’s water levels are too low, predators can walk across the lake to reach hatchlings. If water levels are too high, the flamingos can’t build their nest. High water levels also reduce the overall concentration of cyanobacteria, making feeding less efficient and more time-consuming. When conditions are unfavourable, Lesser flamingos will simply not breed. 

Lesser flamingo building nests in Lake Oloidien, an endorheic lake in Kenya. (Image: Lothar Krienitz, 2013)

One myth that’s circulated online is that Lake Natron is a skin-flaying-lake-of-instant-death-and-suffering. Some articles would have readers believing that simply stepping into the lake means certain death. While the lake is alkaline and therefore caustic, it’s not alien blood.

Even when the lake is its most alkaline, it’s not going to melt flesh. The pH of Lake Natron ranges between that baking soda and bleach. It’s not a lake one would want to swim in and extended exposure can cause burns, but if you’ve ever cleaned your home with ammonia or bleach and spilt some on skin, you know it’s not the end of the world or your existence.

Furthermore, articles online from tourism companies claim that the local Maasai people use the lake’s caustic water to clean and debride the thick skin on their feet (though I couldn’t find other sources/video confirming this). 

Lake Chad

  • Region: West/Central Africa
  • Nation(s): Cameroon, Chad, Niger, Nigeria
  • Climate: Semi-arid & arid Sahel
  • Area: ~2,000km²
  • Status: Endangered (water levels decreasing)

Moving from one side of the African continent to the other. On the border between Nigeria, Niger, Chad and Cameroon lies Lake Chad. The Chari River provides 90 per cent of Lake Chad’s water. This lake falls within the largest endorheic basin in Africa, the Chad Basin. The drainage area of this basin is roughly 2.5-million square kilometres and extends into the Central African Republic and Sudan.

Unlike the other lakes so far on this list, Lake Chad is freshwater. Two main factors contribute to this. The first is that the surrounding soil has relatively low salt content, so less salt is carried into the lake by rivers and runoff. The second factor is groundwater seepage. Water from Lake Chad, and dissolved minerals, seep into groundwater and aquifers. This removes salts from the lake and keeps the water fresh. Though salinity does increase when water evaporates during the dry season, particularly in the north and northeastern portions of the lake.

Like the Caspian Sea, Lake Chad wasn’t always endorheic. As recently as 7,000 years ago (recent geologically anyways), what-is-now Lake Chad was exorheic, draining into the ocean. This massive paleo-lake is known to scientists as Lake Mega-Chad. 

Lake Mega-Chad was many times larger than modern Lake Chad, and existed during the African Humid Period. This period in Africa’s history was marked by higher levels of rainfall and precipitation. At this time, there was so much water that Mega-Chad was able to flow into the Benue and Niger Rivers, and eventually drain into The Atlantic Ocean. As the Humid Period ended, precipitation decreased and water levels dropped, eventually cutting of fthe Lake’s routes to the coast.

Lake Chad has a rich human and natural history. The Chad Basin has been continuously inhabited since at least 500BCE and contains the earliest discovered evidence of hominid occupation in West Africa. Nine cranial specimens belonging to Sahelanthropus tchadensis, which are ~6-7 million years old, were found in northern Chad in 2001. Before this discovery, the only specimens from early humans were found in the Great Rift Valley in Eastern Africa and sites in South Africa.

Several civilizations began along Lake Chad. The earliest of these (that we know of) is the Sao civilization, which lived along the lake from 6th century BCE to 16th century CE.

Lake Chad served as an important crossroads between North Africa, sub-Saharan Africa, and the Nile River Valley. From the 9th to 19th century Lake Chad was home to the powerful Kanem-Bornu Empire. This trading empire was ruled by the Sea (Sayf) dynasty. It wasn’t until conflict between the Kanem-Bornu and other states that the dynasty died out in 1846.

An illustration depicting the Galadima (King/Nobleman) of the Kanem-Bornu empire in 1891.

Historically, the Lake Chad region was rife with life. Visitors to the Kanem Kingdom described an abundance of wildlife including lions, hippopotamuses, and rhinoceros roaming nearby. Accounts up until the early 20th century describe similar diversity in plant and animal life.

Hundreds of bird species reside in the region both seasonally and permanently. Ostriches, Nubian bustards, secretary birds, ground hornbills, glossy ibises, and African spoonbills near the lake. Nile Crocodiles, rock pythons and spitting cobras can also be found. A rich variety of fish species live in the lake too, which are important ecologically and economically.

An African spoonbill, one of the hundreds of bird species that live near Lake Chad. (Image: Charles J. Sharp, 2016).

The well-drained soil of Lake Chad formerly sustained dense woodlands with kapok and ebony trees. However, degradation has altered the habitat, and the result has been a shift to more open woodlands comprised of acacias, baobab, palms, African myrrh, Indian jujube and other species suited to drier climates.

Today Lake Chad is a lifeline to the almost 40 million people who live along it, providing a source of water, food, and income. Fishing is a critical industry on the lake, with more than 40 species of fish considered important commercially. 

A fisherman casting his net in Lake Chad. (Image: MilanGIZ, 2025)

Water from the Chari River is important for agriculture and urban growth. Though, like other endorheic lakes in this list, diversion of water has led to the lake shrinking by 90 per cent in the last 60 years. Urban development and agriculture have also significantly degraded the habitat and contributed to desertification. Habitat loss and climate change are ongoing threats to both biodiversity and communities. 

There are ongoing efforts to try and restore Lake Chad and its surrounding environment, though there are also many challenges still to face. Development policies focus on short-term solutions, and there is a lack of integrated water management on both regional and national levels.

The region is also experiencing conflict over water resources and territory around Lake Chad. The Boko Haram insurgency has been vying for control over parts of the lake, further complicating conservation efforts. The insurgency began in 2013, and as of May 2025 more than 2.9 million people in the Chad Basin have been displaced.

On November 9, 2025, a fight for territory between Boko Haram and ISWAP (another militant group) killed more than 200 people. 

Lake Chad shows how environmental conservation is inseparable from social issues. The loss of water in Lake Chad has contributed to conflict in the region, and conflict in the region impairs people’s ability to address these environmental issues. 

Frame Lake

  • Region: North America
  • Nation(s): Canada (Northwest Territories)
  • Climate: Sub-arctic boreal forest
  • Area: 0.84km²
  • Status: Critical (Eutrophic, no fish)
The shore of Frame Lake in the winter time. (Image: Taylor Holmes, 2023)

Frame Lake is located in the Yellowknife, the capital of Canada’s Northwest Territories. There’s a walking trail around the whole lake. Along is shores is Territories’ legislature and heritage museum. When the lake freezes in the winter, it becomes a thoroughfare for snowmobiles and skiers.

What’s unique about Frame Lake is that it’s not in an endorheic basin and it’s not naturally endorheic, it’s been made that way by people.

Frame Lake is located within the massive Arctic drainage basin in Canada. Historically, Frame Lake would have fed into Great Slave Lake, then the MacKenzie river, before draining in the Beaufort Sea on the Arctic Coast. The lake was home to Lake Whitefish, Northern Pike and Suckers, and was used as a fishing camp by the Yellowknives Dene First Nation, who knew the lake as Enaàti.

The shore of Frame Lake in the winter time. (Image: Taylor Holmes, 2023)

When industrial activity began in the region, the camp was abandoned by the Dene (as a fishing camp, the Dene still live in the Yellowknife area). Frame Lake then served as a popular locale for swimming and fishing in the 1950s and 60s. But, by 1973, studies found that the lake was devoid of fish. So what killed Frame Lake?

Gold was discovered in the Yellowknife area in 1896. In the 1930s and 40s, three mines were opened near Yellowknife: Giant mine, Con mine, and Discovery mine. Giant mine was the most successful of the three, producing a total of 7.6 million ounces of gold between 1948-2004.

The process of extracting gold from ore produces arsenic trioxide (AsO3), also known as white arsenic. This white, odourless, tasteless byproduct is highly toxic. A lack of regulation in the early days led to the release of approximately 19 million kilograms of arsenic trioxide dust into the air via stacks. This contaminated much of the Yellowknife area with arsenic trioxide, including Frame Lake. Containment methods improved in time, and 237,000 tones of arsenic trioxide dust is stored beneath the Giant mine site.

 To this day Giant mine is considered Canada’s most contaminated site.

Giant mine's surface buildings. (Image: Marke Clinger, 2008)

Arsenic contamination was only the beginning of Frame Lake’s death. With the mines came rapid population growth and urban development. Urbanization in Yellowknife disrupted Frame Lake’s inflow and outflow. Specifically, the construction of a major road between 1948-1964, which became a causeway in 1975, slowed outflow from Frame Lake. Eventually these changes made the lake endorheic.

Without an outflow, nutrients and pollutants concentrated the lake. This was exacerbated by the use of Frame Lake as a snow dump. In the winter, snow cleared from streets (full of salts, nutrients and other contaminants) was dumped on the frozen lake. When the ice melted in the spring, these contaminants entered the lake. Excess nutrients in the water caused eutrophication — the proliferation of algae blooms. The algae in Frame Lake depleted dissolved oxygen levels, eventually suffocating the fish within.

A sign along the shores of Frame Lake warning of arsenic contamination. (Image: Taylor Holmes, 2023)

The case of Frame Lake is unique in that it’s one of the only lakes to become endorheic as a result of urban development and population growth. It also serves as an example of how humanity alters ecosystems, and how these alterations can have drastic, tragic and unforeseen consequences.

Recently there have been efforts to revive Frame Lake. An aerator installed at Frame Lake in 2024 now runs in the winter, circulating water within the lake and mixing it with air. The goal is to increase dissolved oxygen levels enough to sustain fish populations. 

Aeration has improved water quality and prevented fish kills elsewhere in Canada. Whether the aeration is working, and if fish can be reintroduced into Frame Lake may take years to determine. 

Great Salt Lake

  • Region: North America
  • Nation(s): United States of America (Utah)
  • Climate: Arid-temperate.
  • Area: 2,500km2 (2022)
  • Status: Endangered (water levels decreasing)

The Great Salt Lake is a hyper-saline endorheic lake in the U.S. state of Utah. Located within is the largest endorheic basin in the Americas, the Great Basin, which spans across the southwest with an area of more than 500,000km² Though not all of this water flows into the Great Salt Lake, it’s the largest lake in the basin.

A railroad built in 1959 splits the Great Salt Lake into a north and south arm, blocking most flow between arm. The three river feed the Great Salt Lake: The Bear, Weber, and Jordan Rivers. All three rivers drain into the south arm, and provide roughly two-thirds of water enters the lake. Precipitation (31 per cent of inflow) and springs (~2 per cent) also supply the Great Salt Lake. 

The causeway blocking flow between the two arms has caused the north arm to become much saltier and less hospitable than the southern arm — though both are saltier than the ocean.

The only organisms that can survive the north arm are halophiles, organisms which adapted to hyper-saline environments. Two species of bacteria are known to inhabit the north arm, which are responsible for its pinkish or violet colour.

Great Salt Lake's north arm. The bright pink colour comes from bacteria living in the lake. (Image: Tiffany A. Rivera, 2015)

In contrast, the southern arm boasts an abundance of life. The great Salt Lake supports 80 per cent of Utah’s wetlands, making it invaluable for wildlife in the region. The wetlands contain a mix of fresh, brackish and salt water. The different microenvironments form critical habitat for birds, fish, amphibians, reptiles and invertebrates.

The infamous “Lake Stink” around Great Salt Lake comes from bacteria living in sediment around the lake. They may be smelly, but they are also crucial for the ecosystem. The smell is caused by the production of hydrogen sulphide gas, which comes from the bacteria decomposing organic matter and recycling nutrients.

Brine flies and shrimp form the base of the Great Salt Lake’s ecosystem and food chain. these small invertebrates live in the south arm’s waters and provide an essential food source to the millions of birds that rely on the lake. Up to 12 million migratory birds from more than 330 species use Great Salt Lake for feeding, breeding and nesting. Eared grebes, bald eagles, common goldeneyes, Wilson’s phalarope, American pelicans, snowy plovers, Black-necked stilts, double-crested cormorants, white-faced ibises, and Great blue herons are just some of the bird species that depend on the Great Salt Lake.

A snowy plover, one of the many bird species that use the Great Salt Lake for feeding and breeding. (Image: Steve Berardi, 2009)

This lake is important for Utahns beyond being the capital’s namesake. The Great Salt Lake contributes roughly 1.9 billion dollars to Utah’s economy. Over 7,700 people are employed in industries directly tied to the lake.

Great Salt Lake produces 14 per cent of the world’s supply of magnesium, which is used in computers, aircrafts, car parts, beverage cans and more; and 40 per cent of the world’s brine shrimp eggs, which are essential to aquaculture. It’s also a source of sulphate of potash, which is a critical ingredient in the production of commercial fertilizers.

Additionally, the climate created by there Great Salt Lake contributes between 5-10 per cent of Utah’s snowpack, extending skiing season by roughly 5-7 weeks (employing another 20,000 people and providing $1.2 billion to the economy).

Like many of the other endorheic lakes on this list, the Great Salt Lake has experienced a drastic decrease in area and volume over the last several decades. Upstream water diversion and overconsumption are the primary cause of the lake’s decline, though climate change is expected to worsen conditions. 

In 2022, declining water levels in the GreatSalt Lake exposed 800km² of lakebed. In addition to the loss of habitat this causes, exposed lakebed creates dust that contains arsenic and other metals, which create a potential public health hazard. This dust also negatively affects agricultural production and property values. When dust from the lake lands on nearby snowpack, it causes snow to melt faster, shortening skiing season and disrupting water supplies.

Lake Texcoco

  • Region: North America
  • Nation(s): Mexico (Mexico City)
  • Climate: Tropical highland
  • Area: 101km², (Lake Texcoco, 2022). 26.57km² (Lake Xochimilco, 2004). 7,868km² (Historically).
  • Status: Critical (drained).
A 3D reconstruction depicting Lake Texcoco and the Aztec Capital Tenochtitlan. (Model: thomas kole, 2023)

Lake Texcoco was once a large saltwater lake system in Central Mexico. The capital, Mexico City, is built on the lakebed of what-was-once Lake Texcoco. This endorheic lake did not slowly dry up, but was deliberately drained by people. 

Historically, water levels in Lake Texcoco varied seasonally, rising during the rainy season and shrinking in the drier months. The Valley of Mexico, is an elevated basin surrounded by mountains and volcanoes, which prevented water in the region from draining. 

Originally Texcoco was one of five lakes in the Anáhuac, or Valley of Mexico. In the 17th century efforts began to drain the lake, but to understand why this was done, we have to go back to the colonization of Aztecs.

The capital of the Aztec Empire, Tenochtitlan, was founded on an island in Lake Texcoco. Ruled by the Mexica people, the Aztec Empire had a population of roughly 6 million people at its height,  with as many as 400,000 living in the capital. The empire was built off the people’s agricultural skills, with the wetlands around Lake Texcoco being reclaimed and irrigated for crops. A complex engineering system handled both flooding and drought while providing stable food and water supplies. The lake was also critical to navigation, connecting several cities within the empire. 

One ingenious form of agriculture used by the Aztecs were chinampas. Chinampas are artificial islands built in the Mexico Valley by layering vegetation, dirt, and mud. Anchored to the lakebed by tree roots, chinampas enabled intensive and productive agricultural production. This served as a strong foundation for the nation, making it possible for them to grow to become one of the largest empires ever in the Americas. 

A chinampa on Lake Xochimilco. (Image: Jflo23)

Then in 1519, Spanish conquistadors led by Hernán Cortés entered Tenochtitlan with the goal to conquer the empire. For nearly two years Spanish and Aztec forces fought one another vying for control of Tenochtitlan. Just as Lake Texcoco enabled the Aztecs to rise to power, so too would it lead to their fall. The final strategy of the Spanish was to drinking water and food supplies to the city, and their plan was effective. On August 13, 1521 the Aztecs surrendered to the Spanish. Not only was this surrender the end of the Aztec empire, it would also mark the beginning of the end for Lake Texcoco.

Once the Mexica were defeated, the next task was to  build a capital for New Spain. There were several possible locations for this new city. The decision to build Mexico City on top of Tenochtitlan and Lake Texcoco is credited to Cortés. This was a calculated political measure, an assurance that conquest was final. Cortés considered it dangerous to leave the old Aztec capital free, lest the indigenous people try to reclaim or rebuild their temples, palaces and monuments.

Conquista de México por Cortés - Conquest of Mexico by Cortés (Painted in the second half of the 17th century, artist unknown)

New Spain’s capital was to be built in the image of the colonizer’s homeland. Geographer and naturalist Alexander von Humboldt noted in an 1827 publication that, “the first conquerors wanted the beautiful valley of Tenochtitlan to resemble in everything the Castilian soil, in the arid and devoid of its vegetation.” 

The Spanish were not familiar with the Anahuac’s floodplains and how to inhabit them. Forests were cut down for building materials and as a fuel source. Rivers were diverted, polluted, or dried up. In 1608 the decision was made to drain the Mexico Basin and Lake Texcoco into the Tula River.

These changes to the water system caused major floods, the worst of these occurring in 1629. A deluge struck Mexico City. It rained for 40 hours continuously, submerging some parts of the city in water as high as 2 metres, and killing roughly a fifth of residents. Mexico City remained flooded for years. It wasn’t until 1634 — five years later — that a drought finally put an end to the flood. 

Flooded streets in Mexico City. (Image: Gobierno CDMX, No Date)

In the 500 years since the defeat of the Aztecs, various governments have attempted prevent flooding. Canals, dikes and dams have been built over the centuries. As a result of draining and diverting water, several aquatic, semiaquatic and halophilic species have gone extinct. 

The diverting, damming, draining, and desiccation of water resources in the Mexico Valley not only destroyed much of the rich ecosystem that once lived, but has also failed to prevent flooding.

The shifts in the water table paradoxically cause both floods and water scarcity. The city has to pump water out to prevent flooding, and at the same time must import clean drinking water into the city to provide for its inhabitants.

Nowadays, only a fraction of what was once Lake Texcoco and adjoining lake remains. One of particular ecological and cultural importance is Lake Xochimilco. This lake was connected to Texcoco before it was drained. 

Canals in Xochimilco. (Image: Carlos Valenzuela, 2022)

Xochimilco’s name means, “where the flowers grow” in the Nahuatl language. During the Aztec empire, Xochimilco was the agriculural centre of Tenochtitlan. Today it’s one of a few places where chinampas are still used. Despite being surrounded by urban sprawl, Xochimilco continues to be important centre for flower production and garden markets. 

Xochimilco is also important for biodiversity, as the lake is home the several endemic species. A species of willow known as ahuejote (Salix bonplandiana) is crucial in preventing erosion in the region. Xochimilco is the only habitat for the axolotl, a species of salamander capable of regenerating entire limbs. The Montezuma frog and acocil (a species of crayfish), are also found nowhere else in the world.

An axolotl. (Image: Mariblubb, 2013)

McMurdo Dry Valleys

  • Region: Victoria Land, Antarctica 
  • Nations: N/A
  • Climate: Polar desert
  • Area: 6.8km² (Lake Vida), 5.2km² (Lake Vanda), 0.25km² (Don Juan Pond)
  • Status: Lake level rising
A satellite image of the McMurdo Dry Valleys. Lake Vanda and Lake Vida are visible in the upper left corner.

The McMurdo Dry Valleys are the driest and coldest desert on earth. Nearby mountain ranges create a ‘rainshadow’ which makes the valleys so arid. It is one of the few regions in Antarctica with soil free of snow and ice. It’s so dry that penguins and seals that wander into the valleys are mummified after death.

Located in Victoria Land, Antarctica, the valleys contain several saline endorheic lakes. In the summer temperatures in the valleys are warm enough to melt ice in nearby glaciers, which feed the lakes despite scant rainfall. Small streams form, but are unable to reach the ocean due to glaciers and mountains blocking the route. Water pools and forms lakes in the bottom several of the valleys. 

Taylor Valley within the McMurdo Dry Valleys. (Image: owamux, 2017)

Antarctica is one of the most inhospitable places on earth, and the McMurdo Dry Valleys are even more extreme. The McMurdo Dry Valleys are so arid and inhospitible that there is little surface life. Penguins and seal mummies are scattered across the valleys. Some of the mummies show signs of being scavenged by skua, a sea bird that sometimes fly through the valleys. The region is also home to 

While not much survives in such a climate, the valleys are not devoid of life. 

Lake Vanda is one of the largest endorheic lakes in the region. Located in the Wright Valley,  Lake Vanda is fed by Antarctica’s longest river, the Onyx River. This lake is covered in ice year-round, but liquid water is found under the surface — along with life. The lakebed is home to microbial mats made of cyanobacteria are able to photosynthesize with what little light gets through the ice.

An aerial view of the Wright Valley and Lake Vanda.

In the west end of the Wright Valley lies another endorheic water body. The Don Juan pond is a small water body fed by groundwater. The pond is only ankle deep, with an area of roughly 0.25km². 

Don Juan Pond is the saltiest water body in the world. With a salinity over 40 per cent, the Don Juan Pond is so salty that the water never freezes, in Antarctica! In comparison, The Dead Sea has a salinity of 34 per cent, and the Great Salt Lake ranges between 5 and 27 per cent. 

The McMurdo Dry Valleys are also a valuable place for researchers. The conditions in these hyper-saline lakes are thought to be similar to the lakes once found on Mars. By studying what lives in these Antarctic lakes, researchers are able to better understand what sort of organisms may have inhabited ancient martian lakes. 

Learn More

If you want to see more of the endorheic lakes on this list, what makes these fascinating systems vulnerable, or how they can be protected, check out my latest YouTube video.

Citations

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  2. Byme, A., et al. (2024). “Productivity declines threaten East African soda lakes and the iconic Lesser Flamingo.” Current Biology. Accessed via https://www.sciencedirect.com/science/article/pii/S0960982224003026
  3. Rabdiya, A. (2025). “Controversial mining project in Tanzania’s Lake Natron halted.” Bird Life. Accessed via https://www.birdlife.org/news/2025/08/22/controversial-mining-project-in-tanzanias-lake-natron-halted/
  4. “Lake Natron.” (N.D.). Beach Safari. Accessed via https://beachsafari.com/en/kb/lake-natron#:~:text=Geography%20and%20Location,2%2C000%20feet)%20above%20sea%20level.
  5. Safarinjema. (2025). Lake Natron: Let’s Dispel the Myths & Misunderstandings.” Tanzania Safari Club. https://tanzaniasafariclub.com/lake-natron-lets-dispel-the-myths-misunderstandings/
  6. “Lake Natron — the Deadly Lake That Turns Animals into Stone.” (N.D.). Ultimate Kilimanjaro. Accessed via https://www.ultimatekilimanjaro.com/lake-natron-the-deadly-lake-that-turns-animals-into-stone/
  1. Gritzner, J. (2025). “Lake Chad.” Encyclopedia Britannica. Accessed via https://www.britannica.com/place/Lake-Chad/Plant-life
  2. “Remnants of an Ancient Lake.” (N.D.). NASA Earth Observatory. Accessed via https://earthobservatory.nasa.gov/images/146304/remnants-of-an-ancient-lake
  3. “Sahelanthropus tchadensis.” (2024). Smithsonian National Museum of Natural History. Accessed via https://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis
  4. “The tale of a disappearing lake.” (2018). United Nations Environment Program. Accessed via https://www.unep.org/news-and-stories/story/tale-disappearing-lake
  5. Niang, A. (2025). “Tackling security and climate challenges in the Lake Chad Basin requires collaboration.” The London School of Economics and Political Science. Accessed via https://blogs.lse.ac.uk/africaatlse/2025/08/21/tackling-security-and-climate-challenges-in-the-lake-chad-basin-requires-collaboration/
  6. Bello, K. (2025). “Boko Haram crush ISWAP fighters in deadly Lake Chad clash.” Daily Post Nigeria. Accessed via https://dailypost.ng/2025/11/10/boko-haram-crush-iswap-fighters-in-deadly-lake-chad-clash/
  7. Egbejule, E. (2025). “Terrorist turf war battle in north-eastern Nigeria leaves about 200 dead.” The Guardian. Accessed via https://www.theguardian.com/world/2025/nov/10/terrorist-turf-war-battle-north-eastern-nigeria
  1. “About the Lake.” (N.D.). Friends of Great Salt Lake. https://www.fogsl.org/about/map
  2. “Meet the Microenvironments.” (N.D.). Learn Genetics. Accessed via https://learn.genetics.utah.edu/content/gsl/micro/
  3. “Great Salt Lake wildlife.” (2021). Government of Utah Great Salt Lake Ecosystem Program. Accessed via https://wildlife.utah.gov/gslep/wildlife.html
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  5. “Great Salt Lake FAQ.” (2013). Natural History Museum of Utah. Accessed via https://nhmu.utah.edu/sites/default/files/attachments/Great%20Salt%20Lake%20FAQ.pdf#:~:text=o%20The%20rock%2Dfill%20causeway%20has%20had%20two,arm%20has%20become%20saltier%20than%20the%20south.
  6. “Solar Evaporation Ponds.” (N.D.). Compass Minerals. Accessed via https://www.compassminerals.com/who-we-are/locations/ogden-utah/
  1. Gavel, M., et al. (2018). “What kills Frame Lake? A precautionary tale for urban planners.” PeerJ. Accessed via https://pmc.ncbi.nlm.nih.gov/articles/PMC6004302/pdf/peerj-06-4850.pdf
  2. “Arsenic trioxide and underground issues at Giant Mine.” (2024). Government of Canada Crown-Indigenous Relations and Northern Affairs. Accessed via https://www.rcaanc-cirnac.gc.ca/eng/1100100027413/1617999134934
  3. Hashmi, N. (2025). “Aerator that could restore fish in Yellowknife’s Frame Lake turned on.” CBC North. Accessed via https://www.cbc.ca/news/canada/north/aerator-fish-frame-lake-1.7420627
  1. Montero-Rosado, C., et al. (2022). “Water Diversion in the Valley of Mexico Basin: An Environmental Transformation That Caused the Desiccation of Lake Texcoco.” Land. Accessed via https://www.researchgate.net/publication/359832565_Water_Diversion_in_the_Valley_of_Mexico_Basin_An_Environmental_Transformation_That_Caused_the_Desiccation_of_Lake_Texcoco
  2. “Sistema Lacustre Ejidos de Xochimilco y San Gregoria Atlapulco.” (2004). RAMSAR. Accessed via https://rsis.ramsar.org/ris/1363
  3. “Historic Centre of Mexico City and Xochimilco.” (N.D.). UNESCO. Accessed via https://whc.unesco.org/en/list/412/
  4. “Lake Texcoco.” (2023). Encyclopedia Britannica. Accessed via https://www.britannica.com/place/Lake-Texcoco
  5. “Xochimiclo.” (2025). Encyclopedia Britannica. Accessed via https://www.britannica.com/place/Xochimilco
  6. “Lake Texcoco, first Ecohydrology Demonstration Site in Mexico by UNESCO.” (2025). UNESCO. Accessed via https://www.unesco.org/en/articles/lake-texcoco-first-ecohydrology-demonstration-site-mexico-unesco
  1. “Dry Valley Tour: Part I.” (N.D.). McMurdo Dry Valleys Long Term Ecological Network. Accessed via https://mcm.lternet.edu/node/1792
  2. “Dry Valley Tour: Part II.” (N.D.). McMurdo Dry Valleys Long Term Ecological Network. Accessed via https://mcm.lternet.edu/node/1794
  3. “Dry Valley Critters.” (N.D.). McMurdo Dry Valleys Long Term Ecological Network. Accessed via https://mcm.lternet.edu/node/1856
  4. “Don Juan Pond.” (N.D.). McMurdo Dry Valleys Long Term Ecological Network. Accessed via https://mcm.lternet.edu/content/don-juan-pond
  5. “Lake Vanda, Antarctica.” (2009). NASA Visible Earth. Accessed via https://www.visibleearth.nasa.gov/images/42109/lake-vanda-antarctica/42110l
  6. Hawes, I.; Schwarz, A.; Sutherland, D.; Howard-Williams, C. (2003). “Aquatic ecosystems of the McMurdo Dry Valleys — the edge of survival.” Water and Atmosphere. Accessed via https://niwa.co.nz/sites/default/files/import/attachments/mcmurdo.pdf

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What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

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Category: HistoryNatureSustainability

The Death of the Prairies

Posted on by Taylor Holmes

How the North American prairies went from one of the most productive to one of the most endangered ecosystems on the continent.

This republished article is part of a collaboration. To view all associated articles and media, click here.

Travis Jimmy John and Ronine Ryder in traditional Nakoda dress. Together the couple run the cultural and ecotourism company Nakota Îtipi & Ryder Style Craft. Photo Courtesy of Travis Jimmy John

In order to understand how the prairies became the most endangered ecosystem on the North American Continent, it is important to know what the prairies once were.

Travis Jimmy John is a Nakoda song-keeper who was raised on Eden Valley First Nation in the Foothills of the Rocky Mountains. Jimmy John would spend his days riding horses with other children, and was taught traditional knowledge from his elders like how to hunt and find water.

Unfortunately, even in his own lifetime, Jimmy John has seen a loss of the rich variety of life that once filled the lands he called home. This can be seen in the country as well. There are fewer animals overall and a noticeably fewer species. 

“You used to see porcupines everywhere out here growing up. Even had to be careful not to step on [them]. So numerous, they were at one point,” explains Jimmy John.

Before Colonization

CREDIT: Taylor Holmes

Prior to European colonization, prairies and grasslands covered much of the continent. From Alberta to Manitoba, and Texas to Alabama, a range of grassland habitats once covered the expanse of the continent. While the climate across the prairies varies – and thus the species that inhabit them – all prairies all consist primarily of grasses, small shrubs and sparse trees. 

“My grandmother said to me… you could camp somewhere and you could hear a buffalo herd moving, shifting around. You can hear them when they go across the land. They go around and it shakes. Life was teeming during the day and the night. So it was not empty, it was full of life,” says Jimmy John.

These rolling prairies provided several Indigenous cultures with ample resources in the form of plants and animals. Additionally, Indigenous people across the prairies routinely helped renew the prairies through prescribed fire – controlled, slow-burning grass fires lit during colder and wetter months. Prescribed fire reduces the risk of massive, scorching grass fires during the dry season, and improves the variety of life in the burned area.

Kyle Lybarger is a forester and conservationist from Alabama. Lybarger runs a TikTok account with over 400,000 followers (@nativeplanttok) where he shares his knowledge and passion of the grasslands with others. Lybarger is an advocate for responsible grassland management and prescribed fire, and he notes that this practice was first done in North America done by Indigenous peoples.

“I try to always pay dues to the Native Americans using this fire…. They saw that wildlife numbers improved in these burnt areas. They were game rich, they were gonna have more rabbits, quail, turkeys, more game species for them to hunt,” Lybarger explains, “But also it improved plant diversity.”

In Alberta, Jimmy John explains that it was primarily the Blackfoot people who used prescribed fire to attract buffalo and all that followed, but all of Alberta’s First Nations worked to keep the environment in balance and take from the land modestly. 

Indigenous North Americans stewarded the environment and enabled the prairies to thrive through responsible use and management, but they did not do it alone.

Two adult bison and a calf on a ranch near Longview, Alta. PHOTO CREDIT: Taylor Holmes

The Bison and the Beaver

The American bison is considered a keystone species to the prairie ecosystem – meaning that the bison’s role is vital in maintaining a healthy prairie and it impacts all the species in the ecosystem. 

Bison wallowing, a behaviour which creates barren patches in the dirt, allowed new species to establish themselves. Their manure fertilized that same earth. Seeds would be carried in the bison’s fur, transplanting plant species throughout the ecosystem.

The buffalo were also a vital resource for Indigenous peoples across the prairies. Grant MacEwan’s book, Tatanga Mani: Walking Buffalo of the Stonies(1969), details just some of the uses for buffalo carcasses furnished fresh meat as well as the principle ingredient for making pemmican for storage; buffalo bone marrow was a good food for babies at weaning time; skins could be made into clothing; buffalo hides sewn together with sinew made a durable tipi covering; the horns were used in making utensils.

“The reason the buffalo was so relied upon was the buffalo was a walking ecosystem where the buffalo went, the birds followed and whatever prayed on the birds, followed the birds and whatever prayed on them, followed and so and so on,” Jimmy John explains, “Buffalo will never drink stagnant water. They’ll always drink fresh water. So they knew where all the springs were in the prairies and out in the foothills here. So by observing the buffalo and being close with them, this is how we knew how to survive. The buffalo taught us this.”

A white bison near Longview, Alta. Within Nakoda tradition, the white bison holds particular cultural and spiritual significance. PHOTO CREDIT: Taylor Holmes

Another vital species for the grasslands are the beaver. Beavers are known as ecosystem engineers due to the way they shape the environment. Removal of trees for dams helps prevent grasslands from becoming forest, and the dams beavers build help increase biodiversity and improve water quality.

The bison and the beaver were vital elements of the North American prairie ecosystem, but now the bison is functionally extinct. A fate narrowly escaped by the beaver. 

So, what happened?​

The Impact of Colonization

There were once an estimated 30 million bison across North America, but now most people who live in their historic range have never seen a bison in person. Colonization of Canada and the United States drove the declines of bison. 

In the United States during the late 1800s, it was official government policy to kill bison, the goal to starve Indigenous people into submission and force them onto reservations. One American colonel is quoted as saying, “Kill every buffalo you can! Every buffalo dead is an Indian gone.”

“The buffalo gave sovereignty to everybody, we’re a sovereign nation. This is why we have treaties with the Crown. You don’t make treaties with conquered people. That’s what I had to point that out. We were a sovereign people and the buffalo helped us to achieve that,” says Jimmy John.

Stacks of American bison skulls waiting to be ground into fertilizer in the United States, circa 1892. PHOTO CREDIT: Burton Historical Collection, Detroit Public Library
In Canada, official policy wasn’t as blatant, however the signing of the treaties had ramifications that would devastate the prairies as well as its people. Land was taken and converted to farmland for crops and cattle, and the bison were now seen as a pest. Additionally, development of the railways fragmented habitats and herds and made it harder for the species to survive.

“The year following Treaty Number Seven brought extremely heavy slaughter of buffaloes, and the Canadian tribesman also suffered. It was difficult to believe: tens of millions buffaloes in 1877 yet virtual extermination of the herds a mere five years later. Only white bones, not quite hidden by the long prairie grass, remained as evidence of the original numbers,"

Grant MacEwan, p. 77 Tweet
In contrast to Indigenous hunting where animals were hunted only until one’s needs were met, and every component of the animal was used, settlers killed the bison en masse for sport.
“Back then [pre-European contact], we didn’t have all this [material things] but we still thrived. Because of the buffalo, the government knew this, what they did was intentional,” says Jimmy John.
 
“They slaughtered the buffalo. They didn’t even eat them. They just slaughtered them. From what I heard they used them for sport down in the US. Some of them [hunters] would be riding on the trains, driving by and shooting them, leaving them there to rot. To us that was a big no-no.”
 

For the beavers, the fur trade would be the cause of their demise. Starting in the 1600s, the fur trade was built upon European demand for furs to make hats. Within a matter of a couple of centuries, demand for fur outgrew supply and beavers were hunted nearly extinct in North America.

Most modern farms use intensive techniques that can deplete soil and damage the environment, such as excess fertilizers, pesticides, and use of monocultures. PHOTO CREDIT: Taylor Holmes

Another impact of colonization would be the introduction of European agricultural methods that began in the 1800s. The introduction of fossil fuels and development of mechanization, synthetic fertilizers, chemical pesticides and irrigation techniques in agriculture during the nineteenth and twentieth centuries as European colonists settled in North America added further strain to the prairies. 

These new forms of industrial agriculture are energy and resource intensive, depleting and creating an imbalance in nutrients in the soil. Further, the use of monocultures – large swaths of only one crop – left the prairies less ecologically productive overall, since the diversity of plant and animal life that made the prairies thrive were pushed out in place of canola and wheat fields.

The Suburban Dream

Lawn is the largest irrigated crop in the United States, and has replaced productive prairie with a habitat that doesn't support much life. PHOTO CREDIT: ArtisticOperations

Another contributor to the loss of prairie habitats across the continent lies right underneath many of our noses. In most communities across the prairies the plants in people’s yards are not native prairie species, nor do the yards boast the diversity the prairies once held. Instead, manicured monocultures and an array of introduced species are the standard in North America.

“All the best grasslands I’ve been to have cogongrass [and invasive lawn grass]popping up all over the place, the only way you could get rid of it was to spray them with herbicides several times over a couple of years,” says Lybarger, “[and] that plant is still being sold in Home Depot. You can go to [garden centres] and still buy cogongrass”

The modern, North American concept of the suburb took hold following the Second World War. With the war over and cars becoming more common people could now afford to live further from their work and other necessities, this allowed for an expansion of the urban landscape with sprawling single-family homes with green lawns and picket fences which replaced the once expansive prairies. 

Unfortunately this suburban dream of a green lawn without a weed in sight is the opposite of a productive, healthy ecosystem. Instead of rich biodiversity and an array of wildflowers, grasses and shrubs, the prairies have been replaced with lawns that require maintenance that damages the ecosystem long-term, like over-dependence on fertilizers, pesticides, and excess watering which create chemical imbalances or toxicity in the environment.

A pile of potash. Potash, which is high in potassium, is used extensively in the production of synthetic fertilizers for lawns and agriculture. PHOTO CREDIT: CatKosianok

Furthermore, this homogenous environment is the perfect breeding ground for pests to proliferate. Because of the lack of diversity, the organisms that would usually help keep insect, arachnid, mammalian and plant pests in balance are not able to live. The result of this is that pests come in to fill the gaps left in the monotony.

Where are we Now?

Practices dating back to the 1600s have contributed to the decline of North America’s grasslands, but the true extent of the damage is only beginning to be understood.

Ken Rosenberg, PhD, is a retired conservation biologist with the Cornell Lab of Ornithology. In 2019 Ken Rosenberg and colleagues published the Decline of the North American Avifauna, which found that North America has lost a net equivalent of 2.9 billion birds since 1970 – and grassland species saw the largest declines by habitat. This is significant not only for bird populations, but also for the ecosystem as a whole.

“What we found that was a surprise is this giant net loss in abundance across all species,” Rosenberg explains, “Some of the most abundant birds that are very common, sort of generalist species like grackles and robins, those sorts of things were also declining.”

While some species, notably waterfowl and birds of prey, saw increases in population — it’s not enough to counteract the overall decline. Birds play a vital role in grassland ecosystems including dispersing seeds, managing pests, and sanitation services, and these massive declines impair this ability for the environment to manage itself. 

Furthermore, these declines act as a canary in the prairies. Birds are one of the easiest groups of animals to observe and record, and humans have been doing so reliably for decades — whereas other groups (mammals, amphibians, insects, plants) are much harder to count and monitor. The fact that avian declines are so expansive, and that even generalist and introduced species are declining, speaks to an ecosystem that is unhealthy. 

“Those broad ecosystems are unhealthy…. When we saw these massive declines in those species which are thought of as pests, and those are declining at the same or higher rate even than of the native species, that’s what really brought home this idea that it’s the underlying health of the environment,” says Rosenberg.

The declines being seen in birds across the continent and prairies is likely just the beginning. Rosenberg and other conservationists believe that sharp declines are likely occurring in other groups of organisms, but these declines have simply not been documented yet – emphasizing the need to act now to slow declines and find balance between supporting our needs and protecting the prairies.

A herd of bison outside of Longview, Alta. PHOTO CREDIT: Taylor Holmes

Read More

What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

Read More »
Category: HistoryNatureSustainability

Is the Bat Trade Sustainable?

Posted on by Taylor Holmes

It’s easy to find bat and other exotic animal specimens, especially with the rise of social media and online marketplaces. Is the trade of exotic wildlife sustainable or ethical?

Bat specimens in a variety of forms are sold online to customers globally. Taxidermy, skeletons, diaphonized and encased specimens can be found for sale online. A 2024 study by Coleman et al found  specimens of one species, the painted bat (Kerivoula picta), in coffins and made into fashion accessories.

Painted bat specimens found for sale during the study (Coleman, J., et al, 2024). Most specimens I found were in similar forms to (b) and (c).

As of publication of this article, I was able to find bat specimens being sold from the U.S., U.K., and Canada — oftentimes selling species that are not native to the seller’s country. Many of the websites selling exotic bat specimens claim their bats are sourced sustainably and ethically, so let’s verify these claims.

Table of Contents

Claims of Sustainability

Non-threatened Species

Several private sellers claim that they only sell bat species that are classified as “Least Concern” by the IUCN. The implication is that if a species is not listed as vulnerable, threatened or endangered, that its sale is sustainable.

In some cases this claim was simply false. Several shops sold Painted Bats, a species which was reclassified to “Near-Threatened” in 2019. The Javan Slit-faced Bat (Nycteris javanica), listed on one site, was classified as “Vulnerable” in 2021. Another species listed for sale, the Java Giant Mastiff bat (Otomops formosus), is “Data Deficient” according to the IUCN. At the very least, some of these businesses are failing to properly research the exotic species they sell, and some may be intentionally misleading customers. 

Furthermore, a species being classified as “Least Concern” by the IUCN does not mean harvesting practices are sustainable. Over half of all bat species classed as Least Concern have unknown population trends. Additionally, hunting rates for many species is unknown. It is difficult if not impossible to verify hunting as sustainable when both bat populations and hunting rates are unknown.

A Painted Woolly Bat (Kerivoula picta).

Natural Deaths

Some sellers in Coleman et al’s study is that the bats sold were not killed, but rather died naturally in the wild and collected.

In the case of the painted bat, it is not possible to collect the number of bats in good enough condition to support the ornamental trade. Painted bats sold online are the result of hunting.

This applies to other species as well. Bats that die in the wild quickly begin to decompose. It is doubtful that complete bat specimens with no visible signs of decay were found deceased naturally in the wild, especially in quantity. 

Population Control

Another claim made is that bats were killed ethically for the purposes of population or pest control. One website claimed bats sold were, “byproducts of wildlife population control programs or pest control.” 

One website's policy on bats they sell claiming specimens are often, "byproducts of wildlife population control programs or pest control."

Bats are culled for various reasons. In Latin America, culls are frequently conducted against the Common Vampire Bat (Desmous rotundus) to prevent the spread of rabies. Australian fruit bats are killed to prevent the spread of viruses and limit damage to fruit crops. Fruit bats are also culled in Africa and Asia to limit damage to fruit crops.

While the culling of bats is done as forms of, “population control” and “pest control,” this does not mean these practices are effective, sustainable or ethical. 

Research has found culls ineffective in managing both disease and agricultural damage. Several studies out of Latin America have found that killing vampire bats did not prevent the spread of rabies or reduce viral load in bats (Streicker et al, 2012; Viana et al, 2023.) It does, however, harm other bat species that share roosts with vampire bats.

Oasalehm 2017
A pair of Common Vampire Bats (Desmodus rotundus) grooming each other. [Credit: Oasalehm, 2017]

In Australia, flying foxes are culled both legally and illegally to combat disease and agricultural damage. Half of the native flying fox species have seen significant population declines (Chapter 10, Schneeberger & Voigt, 2016). Between 2015-2016, over 30,000 Mascerene Flying Foxes (Pteropus niger) were killed in the African nation of Mauritius in attempts to reduce damage to fruit crops — or 37 per cent of the species’ total population. The result of these culls was the species being re-listed by the IUCN as “Endangered” in 2017.

Culling negatively impacts bats, endangers populations, and is ineffective. This brings into question vague claims that the selling of bats killed by these practices is sustainable, especially when the statements made by sellers are vague and generalized to every species listed for sale. 

Captive Bred

"Statements that bats were captive-bred are absurd—bat farms are nonexistent."

Coleman J., et al (2024)

Coleman et al mention sellers claiming bats are captive bred. Fruit bats can and have been captive bred by zoos and for research, but they are not farmed for sale. Additionally, captive breeding of insectivorous bats has been deemed unfeasible.

As of the publication of this article, I was unable to find sellers claiming bats were captive-bred. However, I thought it was still important to address in case someone else comes across the claim.

Scientists and Conservationists Agree

Both bat researchers and conservationists say the trade of bat specimens is unsustainable and unethical. It is simply not possible to hunt specimens sustainably and ethically for international trade and ethically given the lack of data on bat populations and hunting rates. The trade of bat specimens for ornamental use and oddity collecting is detrimental to bats and further endangers species, many of which are already at risk.

"We refute any assertion that the online bat trade is ethical... These bats were hunted. Further, visibly lactating females (based on appearance of the nipples) in photos confirms that harm extends to dependent pups whose mothers are taken.”

Coleman J., et al (2024)

While some cultures do hunt bats traditionally for ornamental uses, Coleman et al say that the ornamental trade is distinct from these practices. Indigenous people in a region hunting bats to use ceremonially for jewelry is not the same as the mass harvesting of bats to sell to people primarily outside of the bats’ native range.

The bat trade is a commodification of wildlife that exploits and endangers bat populations long term. When bat populations around the world are already facing threats from agriculture, logging, urbanization, disease, and climate change among other issues, hunting is an additional, avoidable pressure on populations. 

The Good News

While bat specimens are still readily available online, there has been significant headway when it some to the sale of bats. As of July 2024, Etsy has banned the sale of bats. Ebay also prohibits the sale of bats and their parts. The prohibition of the sale of bats on these massive platforms helps protect bats and set a precedence for better retail practices. 

Better Practices

  • Don’t buy bat specimens. The ornamental bat trade is unsustainable and unethical. Bat researchers and conservationists agree bats should NOT be bought and sold for decoration or collecting.
  • For those who still want bat-themed decor, there are alternative to real bat specimens. Felted and sewn options exist, some of which are hyperrealistic. Realistic replica skulls and skeletons can be found as well.
  • Share the impacts of bat harvesting and collecting on bats. Many of those who buy these specimens are unaware of the harms, and are less likely to buy bats if they know the costs. 

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What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

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Category: Bat MonthNatureSustainability

Red List Friends: The Painted Woolly Bat

Posted on by Taylor Holmes

The Red List Friends is a series showcasing some of the world’s at-risk species from the IUCN’s Red List of Threatened Species. Today’s RedList friend is the Painted Woolly Bat.

Kerivoula picta is the scientific name for the painted woolly bat, also known as the painted bat, “butterfly bat”, “coloured bat”, or “orange brown bat”. This bat species is famous for its bright orange coloration — making it a strikingly beautiful species. However, its beauty puts this species at risk, since it is often hunted for ornamental trade and collecting.

My latest video is all about the Painted Bat: its biology, ecology, threats and how we can help protect this at-risk species. 

  1. Tamowsky, B. (2024). “Exploring Thailand, Part 1: Beauty Among Banana Leaves.” Merlin Tuttle Bat Conservation. Accessed via https://www.merlintuttle.org/exploring-thailand-part-1-beauty-among-banana-leaves/

  2. “Kerivoula picta.” (N.D.). Bat Conservation International. Accessed via https://www.batcon.org/bat/kerivoula-picta/

  3. “Painted bat (kerivoula picta).” (N.D.). Thai National Parks. Accessed via https://www.thainationalparks.com/species/kerivoula-picta

  4. Funakoshi, K., et al. (2015). “Ecology and monogamous system of the painted wooly bat Kerivoula picta in Khon Kaen, Thailand.” Mammal Society of Japan. Accessed via https://bioone.org/journals/mammal-study/volume-40/issue-4/041.040.0402/Ecology-and-Monogamous-System-of-the-Painted-Woolly-Bat-iKerivoula/10.3106/041.040.0402.short

  5. “Kerivoula picta (Pallas, 1767).” (N.D.). Global Biodiversity Information Facility. Accessed via https://www.gbif.org/pt/species/2432543#:~:text=fonte:%20Vespertilionidae-,breeding,likely%20live%20longer%20than%20this.

  6. Balanger, L. (1999). “Kerivoula picta (painted bat).” Animal Diversity Web. Accessed via https://animaldiversity.org/accounts/Kerivoula_picta/

  7. Birkett, K.; K. Weidman and Y. Woo. (2014). “Vespertilionidae (evening bats and vesper bats). Animal Diversity Web. Accessed via https://animaldiversity.org/accounts/Vespertilionidae/

  8. “Painted Bat – Facts, Diet, Habitat & Pictures.” (N.D.). Animalia. Accessed via https://animalia.bio/painted-bat?taxonomy=95#google_vignette

  9. Coleman, J., et al. (2024). “Dying for décor: quantifying the online, ornamental trade in a distinctive bat species, Kerivoula picta.” European Journal of Wildlife Research. Accessed via https://link.springer.com/epdf/10.1007/s10344-024-01829-9?sharing_token=cNU6zybVVsuQxIwziH5Jyve4RwlQNchNByi7wbcMAY7cnp7qWoigBPQFtBoRlzGUpcs47cEQyzWoeFH9HXebmytA8CkYiw1I-eM3Tbh52N5VQecvlpfYWfbrP8aXWYdTqc1dXWgXRI5cIF-KOwtPVmx8kf2LmBW2-Z3q8B1QAkQ%3D

  10. “This Bat is Not for Sale.” (2025). Bat Conservation International. Accessed via https://www.batcon.org/this-bat-is-not-for-sale/

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What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

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Category: Bat MonthNatureSustainability

10 Major Threats to Bats Worldwide

Posted on by Taylor Holmes

Bats play important roles in our ecosystems and economies, but they also face a variety of threats — many of them human caused — which are causing global population declines. What are the major threats to bats and what can be done to protect our flying friends.

Bats are the second most diverse order of mammals, and are found on every continent except Antarctica. They play vital roles in our ecosystems and economies by controlling insect populations, pollinating our crops, and regenerating rainforests, though they may go unnoticed or underappreciated.

In contrast, how humanity changes the environment is impossible to ignore. We alter landscapes in ways no other organism has managed, carving our name across the Earth’s surface. 

Humans have modified 95 per cent of the earth’s landmass excluding Antarctica (BBC), and these changes are driving an ongoing mass extinction of species. Bats are just one of the victims of humanity’s hegemony.

My latest video explores the various threats bats face in depth.

  1. Frick, W.; Kingston, T.; Flanders, J. (2019). “A review of the major threats and challenges to global bat conservation.” Annals of the New York Academy of Sciences. Accessed via https://www.batcon.org/wp-content/uploads/Fricketal2019NYAS.pdf
  2. Voigt, C., Kingston, T. (2016). “Bats in the Anthropocene: Conservation of Bats in a Changing World.” (Individual chapters referenced in order of use). Springer Cham. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9 
  3. Wells, M. (2025). “Landmarks That Can Be Seen From Space: Photos.” Business Insider. Accessed via https://www.businessinsider.com/landmarks-seen-from-space-photos
  4. Lucchesi, E. (2022). “Earthly Objects That Can Be Seen From Space.” Discover Magazine. Accessed via https://www.discovermagazine.com/earthly-objects-that-can-be-seen-from-space-44290
  5. Gray, R. (2023). “How humans have changed the Earth’s surface in 2023.” BBC News. Accessed via https://www.bbc.com/future/article/20231222-how-humans-have-changed-earths-surface-in-2023
  6. Fox, C.; Messina, F. (2013). “Life History.” Oxford Bibliographies. Accessed via https://www.oxfordbibliographies.com/display/document/obo-9780199830060/obo-9780199830060-0016.xml
  7. “Bats 101.” (N.D.). Bat Conservation International. Accessed via https://www.batcon.org/about-bats/bats-101/
  8. Meyer, C.; Struebig, M.; Willig, M. (2016). “Chapter 4 – Responses of Tropical Bats to Habitat Fragmentation, Logging, and Deforestation.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  9. Law, B.; Park, K.; Lacki, M. (2016). “Chapter 5 – Insectivorous Bats and Silviculture: Balancing Timber Production and Bat Conservation.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  10. Williams-Guillén, K.; Olimpi, E.; Maas, B.; Taylor, P.; Arlettaz, R. (2016). “Chapter 6 – Bats in the Anthropogenic Matrix: Challenges and Opportunities for the Conservation of Chiroptera and Their Ecosystem Services in Agricultural Landscapes.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  11. “Appendices I, II and III.” (2025). CITES. Accessed via https://cites.org/eng/app/appendices.php
  12. Mildenstein, T.; Tanshi, I.; Racey, P. (2016). “Chapter 12 – Exploitation of Bats for Bushmeat and Medicine.” Springer Link. https://link.springer.com/book/10.1007/978-3-319-25220-9
  13. “Combatting Illicit Wildlife Trade and Corruption in Maritime Transport.” (N.D.). International Maritime Organization. Accessed via https://www.imo.org/en/ourwork/facilitation/pages/illicitwildlifetrade-default.aspx#:~:text=Wildlife%20trafficking%20is%20estimated%20to,counterfeit%20products%2C%20drugs%20and%20humans.
  14. “Wildlife Trafficking: Why battling this illicit trade is so crucial.” (2025). United States Immigration and Customs Enforcement. Accessed via https://www.ice.gov/features/wildlife
  15. “Stopping the Illegal Wildlife Trade.” (N.D.). The World Wildlife Fund. Accessed via https://www.wwf.org.uk/what-we-do/stopping-illegal-wildlife-trade
  16. Coleman, J., et al. (2024). “Dying for décor: quantifying the online, ornamental trade in a distinctive bat species, Kerivoula picta.” European Journal of Wildlife Research. Accessed via https://link.springer.com/epdf/10.1007/s10344-024-01829-9?sharing_token=cNU6zybVVsuQxIwziH5Jyve4RwlQNchNByi7wbcMAY7cnp7qWoigBPQFtBoRlzGUpcs47cEQyzWoeFH9HXebmytA8CkYiw1I-eM3Tbh52N5VQecvlpfYWfbrP8aXWYdTqc1dXWgXRI5cIF-KOwtPVmx8kf2LmBW2-Z3q8B1QAkQ%3D
  17. Aziz, S.; Olival, K.; Bumrungsri, S.; Richards, G.; Racey, P. (2016). “Chapter 13 – The Conflict Between Pteropodid Bats and Fruit Growers: Species, Legislation and Mitigation.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  18. Kingston, T., Florens, V., Oleksy, R., Ruhomaun, K. & Tatayah, V. (2017). “Pteropus niger, Greater Mascarene Flying Fox.” IUCN Red List of Threatened Species. Accessed via https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.iucnredlist.org/species/pdf/86475525&ved=2ahUKEwjf66iK0ZKQAxX4OjQIHZ_EGh8QFnoECBgQAQ&usg=AOvVaw2-4RSm5y2FHK4xh4gfJ52Y
  19. Waldien, D. (2015). “Re: Bat Conservation International’s Position on the proposed control of Mauritius Fruit Bats Pteropus niger.” Bat Conservation International. Accessed via https://www.batcon.org/files/BCI_MauritiusBat_Culling_20152.pdf
  20. Furey, N.; Racey, P. (2016). “Chapter 15 – Conservation Ecology of Cave Bats.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  21. Chiarini, V., Duchkeck, J., De Waele, J. (2022). “A Global Perspective on Sustainable Show Cave Tourism.” Geoheritage. Accessed via https://pmc.ncbi.nlm.nih.gov/articles/PMC9244007/
  22. “Population.” (N.D.). United Nations. Accessed via https://www.un.org/en/global-issues/population#:~:text=Day%20of%20Eight%20Billion,are%20in%20sub%2DSaharan%20Africa.
  23. “Urban Development.” (N.D.). World Bank Group. Accessed via https://www.worldbank.org/en/topic/urbandevelopment/overview#:~:text=Building%20more%20livable%20cities%20is,people%20will%20live%20in%20cities.
  24. Jung, K.; Threlfall, C. (2016). “Chapter 2 – Urbanisation and Its Effects on Bats ⸺ A Global Meta-Analysis.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  25. Aronson, M., et al. (2014). “A global analysis of the impacts of urbanization on bird and plant diversity reveals anthropogenic drivers.” The Royal Society Publishing. Accessed via https://pmc.ncbi.nlm.nih.gov/articles/PMC4027400/
  26. Kunnari, M. (2020). “The American Lawn.” ARCGIS. Accessed via https://storymaps.arcgis.com/stories/6730610a287e459a84f0c04f74ad8cb2
  27. Sotelo, G. (2022). “What is the Difference Between Native, Non-native, and Invasive Plants?” The Audubon Society. Accessed via https://www.audubon.org/news/what-difference-between-native-non-native-and-invasive-plants
  28. Altringham, J.; Kerth, G. (2016). “Chapter 3 – Bats and Roads.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  29. Furey, N.; Racey, P. (2016). “Chapter 15 – Conservation Ecology of Cave Bats.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  30. “Karst.” (N.D.). National Geographic. Accessed via https://education.nationalgeographic.org/resource/karst/
  31. Snell, G. (2021). “Teeming with life, the destruction of Vietnam’s karsts hits biodiversity.” Southeast Asia Globe. Accessed via https://southeastasiaglobe.com/karst-forest-limestone-mining-vietnam/
  32. “Share of electricity production from wind, 2024.” (2024). Our World in Data. Accessed via https://ourworldindata.org/grapher/share-electricity-wind
  33. Arnett, E.; Baerwald, E.; Mathews, F.; Rodrigues, L.; Rodríguez-Durán, A.; Rydell, J.; Villegas-Patraca, R.; Voigt, C. (2016). “Chapter 11 – Impacts of Wind Energy Development on Bats: A Global Perspective.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  34. Frick, W.; Puechmaille, S.; Willis, C. (2016). “Chapter 9 – White-Nose Syndrome in Bats.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  35. Snowden, W. (2025). “Inside the Bat Cave.” CBC News. Accessed via https://www.cbc.ca/newsinteractives/features/cadomin-cave-Alberta-bats-white-nose-syndrome
  36. “White-Nose Syndrome Killed Over 90% of Three North American Bat Species.” (2021) U.S. Geological Survey.Accessed via https://www.usgs.gov/news/national-news-release/white-nose-syndrome-killed-over-90-three-north-american-bat-species
  37. Wynne, J. (2017). “Appendix III. Procedures prior to entering and after exiting a cave or mine.” U.S. National Park Service. Accessed via https://www.nps.gov/articles/parkscience33-1_61_wynne_appendix_iii_3858.htm
  38. “Clean Caving Procedures.” (N.D.). Save Your Caves. Accessed via https://www.saveyourcaves.org/learn/clean-caving.html
  39. Hormick, P. (2025). “Why Cats and Bats Don’t Mix.” Bat Conservation International. Accessed via https://www.batcon.org/why-cats-and-bats-dont-mix/
  40. Oedin, M.; Brescia, F.; Millon, A.; Murphy, B.; Palmas, P.; Woinarski, J.; Vidal, E. (2021). “Cats Felis catus as a threat to bats worldwide: a review of the evidence.” Mammal Review. Accessed via https://onlinelibrary.wiley.com/doi/10.1111/mam.12240
  41. “Land Pollution.” (N.D.). National Geographic. Accessed via https://education.nationalgeographic.org/resource/pollution/
  42. Rowse, E.G.; Lewanzik, D.; Stone, E.L.; Harris, S.; Jones, G. “Chapter 7 – Dark Matters: The Effects of Artificial Lighting on Bats.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9

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What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

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Category: Bat MonthNatureSustainability

What is White-Nose Syndrome?

Posted on by Taylor Holmes

White-nose syndrome is disease devastating hibernating bat colonies in North America. It’s arrival was mysterious, but it is now one of the biggest threats to bat species on the continent. 

Biologists with the New York State Department of Environmental Conservation are conducting their annual winter surveys of hibernating bats in caves and mines. What they discover during these routine surveys is anything but.

Bats are seen flying out into snowy winter landscapes when they should be hibernating. Inside the cave is even more grim. Instead of cozy colonies cuddling on the ceiling, biologists find heaps of dead bats piling up on the floor of the cave. On the few remaining bats, a white, fuzzy growth is seen on their muzzles, wings and ears.

That was in 2007. At the time, the cause of this catastrophe was a mystery to biologists, but it would mark the beginning of one of the most devastating wildlife epidemics in recorded history.

Provinces and states with confirmed and probable cases of White-Nose Syndrome. Information from whitenosesyndrome.org

What is White-Nose Syndrome?

White-Nose Syndrome (WNS) caused by the fungus Pseudogymnoascus destructans and infects hibernating bats. The disease is named after and identified by fuzzy white growths on the nose, ears, wings and of bats. It also causes bats to wake often and prematurely during hibernation, which leads to starvation.

The fungus is native to Europe where it’s commonly found on bats, but rarely causes mortality. In North America, the disease is invasive and decimating bat populations across the continent. Since its introduction, WNS has become one of the biggest conservation threats to North American bat populations.

(A) bat with WNS growth on its nose. (B) scanning electron microscope showing fungus P. destructans.

Watch my latest video on WNS to learn more about it’s introduction, effects and possible treatments.

Citations:

  1. Frick, W.; Kingston, T.; Flanders, J. (2019). “A review of the major threats and challenges to global bat conservation.” Annals of the New York Academy of Sciences. Accessed via https://www.batcon.org/wp-content/uploads/Fricketal2019NYAS.pdf
  2. Frick, W.; Puechmaille, S.; Willis, C. (2016). “Chapter 9 – White-Nose Syndrome in Bats.” Springer Link. Accessed via https://link.springer.com/book/10.1007/978-3-319-25220-9
  3. Snowden, W. (2025). “Inside the Bat Cave.” CBC News. Accessed via https://www.cbc.ca/newsinteractives/features/cadomin-cave-Alberta-bats-white-nose-syndrome
  4. “White-Nose Syndrome Killed Over 90% of Three North American Bat Species.” (2021) U.S. Geological Survey. Accessed via https://www.usgs.gov/news/national-news-release/white-nose-syndrome-killed-over-90-three-north-american-bat-species
  5. Wynne, J. (2017). “Appendix III. Procedures prior to entering and after exiting a cave or mine.” U.S. National Park Service. Accessed via https://www.nps.gov/articles/parkscience33-1_61_wynne_appendix_iii_3858.htm
  6. “Clean Caving Procedures.” (N.D.). Save Your Caves. Accessed via https://www.saveyourcaves.org/learn/clean-caving.html

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What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

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Category: Bat MonthNatureSustainability

Backyard Friends: The Canada Goose

Posted on by Taylor Holmes
The Backyard Friends is an ongoing YouTube and blog series about animal pals that you might find in your backyard. No matter where we are, we are a part of the nature, not apart from it. 

Table of Contents

Overview

Scientific Name: Branta canadensis

Common names: Canada goose (NOT Canadian goose), honkers.

Conservation Status: Least Concern (population increasing globally)

Range: Native to North America, introduced to Western and Northern Europe, New Zealand

Description:

Canada geese are easily identified by their buff or brown coloured body, black neck and white chinstrap marking. They weigh up to nine kilograms (20 pounds), with an average wingspan between 127 and 170 centimetres (50-66 inches). Generally getting bigger as you travel south, and darker further westward.

The only species that could be mistaken for Canada Geese are Cackling Geese – which were considered four subspecies of Canada Geese until 2004 when they were recognized as their own species. They are smaller and have shorter necks, and often flock alongside Canada geese, adding to confusion.

Canada Goose, photographed in Toronto, ON (Taylor Holmes/2023)
Cackling Goose, photgraphed in Anchorange, AK (TRinaud/2023)

Habitat

Range

Range of Canada Goose, including introduced ranges. Map made with data from the IUCN and Merlin Bird ID. (Taylor Holmes/2025)

Native to North America, Canada geese breed across much of Canada and the northern United States. In winter they usually migrate to the southern United States and Mexico. However, some populations winter in northern areas with access to open water and food resources, even in extreme cold.

My hometown Calgary is one such city. Here Canada geese reside year-round, toughing it out along the shores of the Bow and Elbow rivers even as temperatures push -40.

A gaggle of geese in the Bow River in Calgary

Canada geese have also been introduced to Europe and New Zealand. Specimens were first brought to Europe in the 17th century for royal collections – namely those of King Charles the Second of England and King Louis the Thirteenth of France. Populations were later released in Europe and New Zealand to be hunted for sport.

Habitat

These adaptable creatures can be found in a variety of habitats, including tundra, wetlands, grasslands, agricultural and urban areas – though almost always near water. They thrive so much in our cities, parks, golf courses and parking lots they are often considered pests, and can be found in some pretty funny places. 

Once I saw a pair of geese attentively raising their brood outside of West Edmonton Mall. The couple were nesting in a little service area beside one of the entrances.

Diet

Diet: Omnivorous

On land they frequently forage for food in groups, but they also dabble in water for plants and small animals. Some subspecies of Canada goose (such as B. canadensis maxima) have adapted to urban life, grazing on domestic grasses (lawn) year-round.

  • Spring/Summer diet: primarily grasses and sedges – including skunk cabbage and eelgrass. In the water they dabble for aquatic plants and small crustaceans, mollusks or fish.
  • Fall/Winter diet: berries, seeds, and grains – including crops like corn and wheat.

Predators

Canada geese and their eggs are predated by wolves, coyotes, foxes, bears, wolverines, eagles and ravens. 

Humans also hunt Canada geese, harvesting roughly two-point-six million geese annually in North America. They are also hunted in Sweden, Denmark, Norway, and Germany.

Bald eagles are on of the Canada Goose's predators.

Behaviour

Aggression

Within their range, Canada Geese have a bad reputation, and are known for being aggressive… but their infamy isn’t entirely warranted, and their wrath is often avoidable.

Like many other animals, these geese do get more aggressive and territorial during mating season and when nesting.

Watching for warning behaviours like hissing, honking, vibrating head feathers and pumping their head with their bill open and tongue raised, can prevent unpleasant encounters. In my experience, you can usually just give geese and goslings a bit of space as you pass. 

However, managing aggression isn’t always as simple as “give them space.” Geese can be quite the menace if nesting near someone’s residence. Every now and again there’s a news story about nesting Canada Geese absolutely terrorizing people who happened to live near a pair.

Reproduction:

Reproduction

Mating system: Monogamous, Assortative.

Generally Canada geese choose partners who are similar in size to them, a system known as assortative mating. Males tend to be the larger of the two. In the wild they construct their nests on the ground near water, but they’ve also learned to utilize rooftops, balconies, and parking lots for nesting.

These birds are in it for the long haul. They mate for life and have very low “divorce rates”. Pairs will stay with each other year-round and both males and females care for offspring, which is rare in geese and ducks.

“Divorce was rare in my geese; usually a change in mates meant the death of the former partner.”

Michael R. Conover, 2009, p. 278

Canada Geese have one brood a year with between 2-8 eggs. Goslings have yellow plumage, and are precocial, or relatively independent at birth. They are able to leave the nest within 1-2 days after hatching, and are able to swim, feed and dive shortly thereafter.

These geese are known to form “gang broods”. These occur when multiple broods are combined together, the largest of these exceeding one-hundred goslings.

A gang brood being watched by two sets of parents (U.S. Fish and Wildlife Service/2012)

Sometimes this occurs before hatching, called a pre-hatch brood, where a goose lays eggs in the nest of another, and her children are raised by the other parent. Post-hatch broods occur after hatching, when a parent loses or abandons its children, or multiple couples merge broods to care for them cooperatively.

Some of the possible benefits of gang broods include greater predator protection through the dilution effect – more goslings means any one gosling is less likely to be picked out by predators. It may also provide better access to foraging, since larger goose families are dominant over smaller ones.

But not all Canada geese form gang broods, suggesting they may not be innately better than raising goslings individually. The main theorized drawback of gang broods is intra-brood competition, since being in a brood with 99 other goslings means having to share grazing areas, food access, and parental care with 99 other goslings.

Conservation

A drawing depicting Canada Goose hunting from a 1888 guide on hunting and waterfowl.

While so abundant and widespread now that they are often seen as a nuisance, Canada Geese were once on the brink of extinction. In the early 20th century, habitat loss and hunting had decimated Canada Goose populations, and they were nearly driven into extinction. However, thanks to better regulations and conservation efforts including the Migratory Birds Convention Act.

Nowadays, the Canada Goose is considered Least Concern by the IUCN, with both their range and populations increasing since the 1940s. While roughly two-point-six million Canada Geese are hunted annually in North America, this doesn’t seem to be impacting populations. 

Potential threats listed on the IUCN include shifting habitat due to climate change and extreme weather. Ranges for the Canada Goose have shifted northward, though this does not appear to currently impact population trends. 

Citations

  1. “Branta canadensis (Canada Goose)” (2018). IUCN RedList.
  2. “Canada Goose.” (N.D.) All About Birds.
  3. Attenborough, D. (1998). “The life of birds.” BBC London. p. 299.
  4. Yarza, F. (2014). “Branta canadensis.” Animal Diversity Web. 
  5. Richard-Craven, M. (2022) “10 Fun Facts About the Canada Goose.” The National Audubon Society.
  6. Rush, C., & Coluccy, J. (2021). “Understanding Waterfowl: Super Broods.” Ducks Unlimited.
  7. “Canada goose.” (2025). Encyclopedia Britannica.
  8. Conover, M. (2009). “Gang Brooding in Canada Geese: Role of Parental Condition and Experience.” The Condor/The Cooper Ornithological Society.

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What are Chinook Winds?

February 28, 2026 No Comments

Chinook winds are a fascinating phenomenon experienced in the eastern Rocky Mountains and western Canadian Prairies and Great Plains. Learn

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Category: Backyard FriendsNature