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Wildlife around the world

Scientists around the world have noticed a wide variety of animals changing their habits in response to climate change. Some have been successful in adapting to climatic change. Others have not been as fortunate.

Marine and freshwater fish - File #: 3197896Pacific salmon

Usually restricted by cold water temperatures, Pacific salmon species such as sockeye, pink salmon and Coho salmon have been found far outside their normal ranges (1). A Coho salmon was found almost 2000 km further into northern waters than usual (2). Temperature increases in the Arctic as a result of climate change have allowed these temperate-water salmon to expand their ranges.


Trout are a cold-water fish, thriving in spring- and glacier -fed water. Already struggling under the burden of pollution, erosion and diversion projects, trout are now - literally - in hot water. As climate change raises temperatures in North America, streams, rivers and lakes are becoming too warm for trout to survive (3). Brook, brown and rainbow trout will lose up to 76% of their habitat if greenhouse gases continue to build up and trap heat in the atmosphere (4).

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Insects and other invertebrates


In North America and Europe, over 35 species of butterflies have been expanding their ranges northward by up to 200 km (5). In the western U.S., Edith's Checkerspot butterfly has not only shifted its range 92 km northward since the early 20th century, but has also gained 124 m in elevation (6).

Coral reefs

Coral reefs provide food and shelter in one of the most biodiverse ecosystems on earth. Coral reefs have undergone global mass-bleaching events whenever sea temperatures have exceeded summer averages by more than 1°C for several weeks (7). Since 1979, mass-bleaching events are become more frequent and destructive. In 1998, the most severe event thus far occurred, killing off 16% of the world's coral reefs (8). New evidence suggests that that the increased levels of carbon dioxide in the atmosphere may weaken the corals' calcium carbonate skeletons, making them more vulnerable to storm damage and other erosion (9).

Coral reefs cover less than 1% of the ocean floor, yet provide food and shelter for over one-third of all marine fish (10).

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Nutritious whitebark pine seeds are a major food source for grizzly bears in western North America. The ability of a grizzly sow to successfully bare young is linked to pine seed abundance - more seeds mean healthier bear families (11). Unfortunately, whitebark pine is vulnerable to the impacts of climate change. Warm temperatures allows pine blister rust - a deadly, introduced fungus - to thrive and spread, killing up to 90% of whitebark pine in a given area (12). Less trees, less seeds, less bears.

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Reptiles and amphibians

In Costa Rica and North America, disastrous losses in frog, toad and salamander populations are climate related (13). With less winter precipitation, breeding pools aren't deep enough to protect eggs and tadpoles from damaging ultraviolet rays. Weakened by UV-B radiation, they become susceptible to fungal infection, dying at epidemic rates. With inadequate water, over 50% of western toads succumb to fungal infection (14). Image of "painted turtle" by Kenneth M. Gale, Image #4322024,

In many reptiles, temperature determines the sex of offspring. Increased global temperatures could seriously skew sex ratios. A shortage of either sex could undermine a species' ability to replace itself from generation to generation. In painted turtles, offspring sex ratio is correlated with mean July temperature (15). Even a modest temperature increase (2 - 4°C), could dramatically reduce the number of male turtles produced (16).

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Many songbirds are laying their eggs earlier in the United Kingdom. One-third of U.K. bird species are starting families 8.8 days sooner than usual (17). Birds of every feather are picking up the nesting pace: waterbirds, resident and migrant insect eaters, and seed-eaters are all responding to earlier spring-like temperatures and longer growing seasons.


Arctic regions will experience the strongest global warming as carbon dioxide levels rise. Over half of the tundra is expected to be replaced by boreal forest. Approximately 14 million Calidrid sandpipers (95% of the world's population) raise young on the tundra (18). Scientists expect 7.5 million sandpipers to be lost as climate change eliminates their habitat (19).


In four years of unprecedented warm winters Adelie and Chinstrap penguin populations on King George Island have declined by 40 and 35% (20), respectively. Sea-ice cannot form on Antarctic seas warmed by climate change. The krill that typically feed on the algae are the primary food source of the penguins. As krill becomes scarce, penguins starve.

Arctic species

Many arctic animals rely on the predictable ebb and flow of sea ice for food and shelter:

Arctic cod

Arctic cod are an important food source for seals and whales. Cod gather underneath sea ice, feeding on zooplankton. The abundant zooplankton subsist off algae that grows on the underside of the ice.

See also Ringed seals in Manitoba Wildlife


Walruses require a delicate balance of ice thin enough to break through with their heads, but thick enough to support their weight (21).


Narwhals are almost always found close to sea ice. They prefer to forage for arctic cod at ice edges and cracks (22).

See also Beluga whales in Manitoba Wildlife

Bowhead whales

Bowhead whales feed on zooplankton, using sieve-like baleen in their mouths to filter massive mouthfuls of the tiny crustaceans (23). Without sea ice, the whales will have little to eat.