Most Americans are familiar with Chickadees–a common North American bird with a signature Chick-a-dee-dee-dee call it was named after. These small birds are everywhere, and come in different species such as the Chestnut-backed Chickadee, Black-Capped Chickadee, and the Carolina Chickadee.
All total there are 7 different types of Chickadees in North America. Two of them, the Black-Capped Chickadee and the Carolina Chickadee, are so similar looking that they sometimes get confused themselves and crossbreed.
These two species typically live in completely different parts of North America, the Black-Capped Chickadee prefers the cold north, where the Carolina Chickadee prefers to live in the warmer south. The only place where hybrids occur is along a narrow border where their territories overlap.
According to researchers at Cornell Lab of Ornithology, Villanova University, and Cornell University, that border is moving due to climate change. Carolina Chickadees are moving farther and farther North, as winter in the North continues to warm.
The researchers discovered this during a 15 year long study enlisting the help of birders. They banded several different birds from the two different species, and kept track of where they went, what they did, and who bred with whom.
On average, the Carolina Chickadee has been moving north about 0.6 miles per year, and they moved almost perfectly in sync with the warming of winter.
What does this mean for the Chickadee? Mostly, it means that the Chickadee you see in your home state isn’t the one you are used to. Chickadees are adaptable, but many bird species aren’t.
Scott Taylor, the lead author of the 2014 study on Chickadees had this to say:
“The rapidity with which these changes are happening is a big deal. If we can see it happening with chickadees, which are pretty mobile, we should think more closely about what’s happening to other species. Small mammals, insects, and definitely plants are probably feeling these same pressures—they’re just not as able to move in response.”