Caribou depend on grasses beneath the snow to sustain themselves in winter and spring. As the Arctic warms, snow can melt and then refreeze, creating a layer of ice impenetrable to their hooves, cutting off this vital food source. Arctic Caribou populations have dropped by nearly 50% in most of their habitat.
Caribou are compromised in a warmer Arctic
Polar bears adapting to change
The great polar bear has had to adapt to deep changes in its habitat. Dwindling sea has brought them into more contact with humans, because they use sea ice to move long distances to hunt and can become stranded when the ice disappears.
Arctic bird populations are suffering massive decline
Seabirds travel incredibly long distances to reach their arctic breeding grounds. Populations of many species are plummeting and several factors, including climate change, are behind their decline.
Climate Chaos: Wildlife
Wildlife are completely dependent on their ecosystems to survive. Hundreds of thousands of years have given each animal its space to thrive in symbiosis with the land, plants and animals around them. For some species, in more gentle places on the earth, there is flexibility for them to adapt to changing conditions. In the Arctic, there is often a razor thin line between survival and rapid decline. Climate chaos has wrought many changes to the Arctic landscape. Sea ice is dwindling. For polar bears, this means they can become trapped on land and limited to a small area for hunting. Warmer winters and springs means that caribou now find their primary food source trapped below a thick layer of ice because melting snow has become a frozen icy barrier. Sea birds can find that the insects needed to raise their young have already hatched and gone when their babies are born; an earlier spring melt triggers a cascade of changes in their breeding grounds. The Arctic is harsh and each animal that has grown into that environment has a small space of optimal conditions, into which it fits. The new Arctic is a different place, and many of the animals there are not prepared for the changes.
It's all tied together
Polar bears are king of the Arctic. They are the largest predator around and very well equipped to survive in the harsh conditions of their Arctic habitat. Media coverage of polar bears has made them the most visible species under threat by the extreme changes climate chaos has wrought in the far north. The primary threat for the bears is diminished sea ice. The Arctic has warmed an average of 2.1 degrees celsius in the last 20 years and the landscape has changed in significant ways. Sea ice now melts earlier in the year and more of it disappears each summer. For the bears, this poses a significant problem. They use the ice to hunt their favorite food; seal. Seals live on the ice and where it goes, they follow. Bears move from land to ice and ice to land, to give birth to cubs and to hunt. When the sea ice melts and is far from the coastlines, bears are unable to move around and can be trapped on the land until the ice returns in the fall. An adaptable species, the bears will turn to other food sources, as the seals become inaccessible. They’ll eat just about anything and one tasty treat they’ve discovered is egg. Landed bears have been known to eat 90 percent of the eggs in a nesting site, if they come upon it. For the vulnerable birds in these places, the arrival of bears before their eggs hatch can be catastrophic. Sea bird populations have declined up to 70 percent in some species. Many factors are at work here, but bears turning to eggs as a food supply does not bode well for them. Polar bears have been protected in some areas, and are not yet considered a threatened species. However, two populations studied by scientists, found that average adult weight has dropped and fewer cubs survive. Food supply and habitat loss are likely culprits as the bears struggle to survive in a changing Arctic landscape.
Great change over great distance
There are approximately 200 species of birds in the Arctic. Most of the birds found here come from other parts of the world as part of a migratory pattern that follows food sources. Some birds travel up to 9,000 kilometers each year, coming to the Arctic to breed. Breeding is obviously a key part of their lives and the safety and abundance of food in their breeding grounds is key to success in these places. Climate change has brought significant pressures to the birds during this most vulnerable part of their lives. A critical piece to the bird’s survival is the hatching of insects in the breeding ground, providing an easy and abundant food source for baby birds. Warming temperatures in the Arctic spring and an earlier onset of springtime conditions has led to a mismatch of timing with the hatch of the insect eggs and the hatch of the bird eggs. Some species are being born to a dearth of food because the insects have already come and gone. More polar bears are eating bird eggs as sea ice decline keeps them onshore and isolated from seals, their preferred food source. Changes in permafrost that have allowed larger shrubs and even trees to move north have altered the ecosystems and the animals that inhabit them, bringing fox and other, small predators to places the birds nest. Combining the pressures in the Arctic with significant changes along the rest of their migratory routes, some bird species are suffering declines of up to 70 percent. The one exception is the goose. The number of geese in the Arctic has exploded and they are competing with smaller bird species for habitat and food. The further development of oil and gas reserves adds to the woes of sea birds due to their absolute vulnerability to pollution at shorelines. Scientists consider the state of migratory birds in the Arctic to be one of emergency. The extreme challenges birds face requires a global shift in caring for them all along their migratory routes and in their nesting sites. They need humans to make sure they can make it home again.
While climate records are being routinely broken, the cumulative impact of these changes could also cause fundamental parts of the Earth system to change dramatically and irreversibly.
Scientists with the University of Alaska Fairbanks, U.S. Geological Survey and other institutions have documented 56 beaver complexes that have been built since 1999 along rivers and creeks in Arctic northwestern Alaska.