Birds and Climate Change: Canaries in the Coalmine

This year’s Blog Action Day on climate change falls right at the end of an amazing ecological spectacle in North America: the annual southward migration of millions of birds headed for warmer climes for the winter. Our yards are quieter, our skies are emptier. And today’s a good day to think about the impacts facing these departing bird populations as a result of climate change.

In many instances, we read about the projected impacts of a changing climate on a country, or an ecological community, or a species, and the effects seem hard to imagine because they are so distant. Well, for many bird species, including many Canadian birds, the effects of climate change are being felt now. Not generations from now. Not 50 or 20 years from now. Now.

Birds are laying their eggs earlier to correspond to warmer spring temperatures. They are migrating earlier – or, if not, like some long-distance migrants, they risk arriving on their breeding grounds after their insect food sources have already peaked. They are shifting their distributions more northward. They are suffering from changes in ecological communities resulting in increased parasites and decreased food supply.

What does this mean? Birds can fly, after all, you might think, so can’t they just fly to habitat with a more suitable climate? Well, yes, in some cases. But this is not a strategy that will work forever, and it won’t work for all species. In some cases, there just won’t be any more suitable habitat.

We are already seeing this in Arctic breeding birds. For example, the Ivory Gull is one of the most northerly nesting Canadian birds. Ivory Gulls forage along sea ice. As sea ice is disappearing, so too are Canadian Ivory Gulls: they have declined 90% in the past two decades. Consider that 15% of the world’s birds breed in Arctic areas and you quickly understand that these impacts will extend well beyond our beautiful Ivory Gulls.

It’s time for Canada to take significant action on climate change, to save all our bird species that are canaries in the coalmine.

Photos: Shorebirds in flight (Shutterstock); Ivory Gull (Simon Stirrup)