If your education was like mine, at some point in elementary school you were taught that birds migrate south in the winter. “South” was usually assumed to mean Florida. In fact, a woman I met recently told me that she honestly thought ALL birds went to Florida for the winter. I was stunned, but then I realized that before I got into birding I had never thought about migration beyond the tiny bit of info I’d been fed in school. I know more about bird migration now though, and there’s one particular aspect of it that I want to share with you, one that might impact how you feel about your morning cup of coffee.
But first let’s get a few things straight. Yes, birds tend to live and breed farther north in summer and then go south for the winter. But “north” and “south” are relative. Some birds breed in the Arctic and then fly south only as far as southern Canada or the northern U.S. for the winter. Other birds breed in Canada or the northern U.S. and fly all the way to Central or South America for the winter. Most warblers rely on insects as their main food source, so when insects aren’t available up north, they have to go south. A few species can survive on berries and seeds though, and those birds are sometimes able to stay up north all year (like the Yellow-rumped Warbler, for one).
The Prothonotary Warbler shown at the top of this post will probably spend next winter in Nicaragua, Costa Rica, or even Columbia. Then he’ll fly back north, arriving here in Michigan in late April or early May. If he flies from Bogota, Columbia, to Detroit, that’s a distance of 2,653 miles (4,270 km). Think about it: This bird is only 5.5″ long (14cm). If my math is correct, just flying ONE mile is 11,520 times the length of its body. That would be like me (five foot five inches tall) flying almost TWELVE miles with nothing but my own body strength. When you multiply those numbers by more than 2,500 miles, your mind –and your calculator– will explode with the effort of comprehending it all. Amazing little creatures, aren’t they?
So what do our warblers need while they’re down south? Well, they need a habitat that supports lots of insects–someplace where all the insects haven’t been killed with pesticides. Up until a few decades ago they found a wonderful supply of insects on coffee farms, where coffee was primarily grown in the cover of shade trees. But when the big coffee companies found that they could grow more coffee cheaper if they cut down all the trees, they began to do exactly that. Millions of acres of trees were destroyed in the name of profit. Even then the warblers might have had a chance at living on coffee plants. But the high-yield coffee plants that grow in the sun require lots of pesticides and fertilizers. And those chemicals kill even more of the insects that the warblers depend on for their survival.
Think about it. Even if “our” birds are happy and healthy up here where they breed in the summer, what happens if they can’t survive on their wintering grounds? They won’t be coming back north in the spring, that’s for sure. Imagine what life up north would be like with zillions of mosquitoes and no birds to help you out with that little problem. See how our world is tied together? The health of our ecosystem in North America is directly tied to that of South America. To care for the birds that eat our insects, we also have to make sure they are cared for in their southern habitats too.
This is why there’s an effort to get farmers to go back to the traditional method of growing coffee on shaded plantations that support the birds. Many people say that shade-grown coffee tastes better too, imagine that? Right now there’s only one brand of coffee that has the Bird-Friendly certification from the Smithsonian Migratory Bird Center, and that’s Birds & Beans. I don’t mean this to be a commercial for them, but I just wanted to let you know that there are lots of other companies marketing coffee as “bird safe” or “shade-grown,” even though some of those so-called certifications are questionable. If it matters to you, you can read about the certification process on the Smithsonian Migratory Bird Center website.