Bird-eat-bird world

Post by Jen Berlinghof

I remember the first time I saw it happen. It was a frigid Sunday in February, sixteen years ago. I had just started working for the Lake County Forest Preserves. The deep cold, the kind that temporarily freezes your eyelashes together every time you blink, kept potential hikers away from Ryerson Conservation Area that day. I ventured out only to fill the bird feeders, and the chickadees, juncos, cardinals, and woodpeckers quickly gathered around for a feast. I thought they would be my only visitors of the day. Then, a cacophony of bird wings ruptured the quiet. Bird visitors fled from the feeders in all directions. In a low hanging branch of a nearby oak, one bird remained: a Cooper’s hawk. It was devouring a mourning dove that had just been pecking around under the feeders only moments before.

Cooper's hawk eating birdWhile perhaps shocking the first time you see it, Cooper’s hawks targeting bird feeders has become a more common occurrence over the years. These medium-sized hawks with long, striped tails, are forest dwellers that specialize in darting nimbly through the woods in pursuit of their favorite food—other birds. Rock doves and mourning doves are common prey, easy targets at bird feeders, which the hawk captures in its sharp talons and kills by squeezing.

According to data from Project FeederWatch, a citizen science survey of birds that visit feeders at backyards, there has been a significant increase of Cooper’s hawks visiting bird feeders over the past 25 years. There are a multitude of reasons behind this rise in visitation. Hawk populations in general have increased since the ban of DDT in the early 1970s, a pesticide that caused the thinning of egg shells in raptors and other birds.

Additionally, there has been a significant increase backyard bird feeding. Over 40 percent of American households report feeding backyard birds, which congregates a Cooper’s hawk’s favorite foods into one big buffet. Scientists have found that this growing food source may contribute to some hawks staying put during the winter in lieu of migrating each fall. Research thus far has not provided evidence that these newer winter residents have caused significant declines in songbird species at feeders.

8133197634_f09d083757_k

It’s fascinating to find the food chain in action in our local forest preserves and even our own backyards. While the winter bird feeder season is ending soon, we are on the precipice of spring when many other animals will rise from various forms of winter “sleep.” Others will migrate back from afar.fox

Each spring our interactions with wildlife tend to increase. The spring issue of our quarterly Horizons magazine, features an article on “Living with Wildlife.” The feature includes tips on how to best interact with animals that have found suitable habitat in your backyard or other urban areas. By remembering a few key factors about living alongside wildlife, we can avoid potential problems, and enjoy the excitement that these animals bring to our backyards and communities.