An important new analysis on the effects of climate change on birds was released this week by our BirdLife partner in the United States, the National Audubon Society. The analysis of four decades of Christmas Bird Count observations reveals that North American birds are moving northward and inland towards cooler temperatures in response to a changing climate.
Specifically, 58% of the 305 widespread species that winter on the continent have shifted significantly north since 1968, some by hundreds of kilometres. The ongoing trend of movement of these species is closely correlated to long-term winter temperature increases. The evidence is striking for some species: Purple Finch, Pine Siskin and Boreal Chickadee have dramatically shifted their home ranges by hundreds of kilometres further north in the boreal forest over the past four decades.
Even more alarmingly, some groups of species are running out of places to go in response to a changing climate. Only 38% of grassland bird species demonstrated significant shifts — the grassland habitat for species like Eastern Meadowlark, Vesper Sparrow and Burrowing Owl is already significantly depleted making the strategy of climate adaptation through range shifts for these species impossible.
What are the Canadian implications of these startling findings? Here are three:
1) The effects of global warming are being felt now. Species are being impacted in tangible, measurable ways. We can’t continue to assume that the effects of global warming are theoretical, or so far away as to be impractical to act on. We are already seeing the effects to birds.
2) Conservation decisions need to incorporate consideration of climate change adaptation. Protected areas networks are essential, but they must be big enough to allow species to adapt to a changing climate. Promises by the governments of Quebec and Ontario to protect half of their boreal forest habitat are a good step in this direction, and one that will help with climate change mitigation too.
3) We need concerted, global and national action on global warming. The Audubon report points out:
It took legions of bird-loving citizen scientists to document how North America’s birds are responding in the face of global warming. It will take action by America’s millions of bird enthusiasts—and their elected representatives—to address the problem of climate change while there’s still time.
The same can be said for Canada’s bird enthusiasts who tirelessly contribute to Christmas Bird Counts every year. It can certainly be said too about our elected representatives. We need both citizen action and concrete policy action to reduce the dramatic impacts that global warming is having on our bird populations. As this report on the Audubon analysis states, “When it comes to global warming, the canary in the coal mine isn’t a canary at all. It’s a purple finch.” Now that we know about the Purple Finch, let’s do something about it.
Photo: Boreal Chickadee by Jeff Nadler