Winter has finally tightened its grip on Central Illinois. Crisp air and frozen ground define the landscape that was home to warm breezes and green growth not so long ago. In the shift of the seasons, nature also adapts to these new realities.
Some birds that have been here all summer leave us and fly south. The Summer Tanager that sang in the oak tree all summer near the visitor center at Tawny Oaks is now in Costa Rica. Some birds like the Northern Junco, at the feeder today, migrate from the north and over-winter here in Central Illinois. There are also the year-round residents like the Downy Woodpecker on the suet feeder that will nest here in the summer and remain here for the winter.
As I look out the window today, I see a group of colorful House Finches feeding at the thistle feeder. Suddenly, there’s a flurry of activity. Birds scatter in all directions as a swift, gray shape streaks through the flock of birds. One of the House Finches disappears and is replaced by a few floating, purple feathers. The feathers drift away in the wind. A young Cooper’s Hawk is finding the birdfeeder a productive location to grab lunch today. The hawk now sits in the oak tree with the House Finch in his talons. Winter is a desperate season. This hawk will live to see another day. The finch has helped make that possible.
The Cooper’s Hawk is about the size of a crow, so it’s a medium sized hawk. It has a long tail, and short, rounded wings. Adults are steely blue-gray above with warm reddish bars on the under-parts and thick dark bands on the tail. Juveniles are brown above and crisply streaked with brown on the upper breast, giving them a somewhat hooded look. It belongs to a group of hawks known as Accipiters. These woodland hawks specialize in precise flight and hunting small birds for food.
The Cooper’s Hawk is a year-round resident in our wooded parks. They are actually a conservation success story. In the 1970s, their populations were so low that they were listed as “Endangered” in the state of Illinois. Their populations were decimated by eggshell thinning, a condition resulting from the insecticide known as DDT that was used in agriculture. Many know the story of how DDT impacted Bald Eagles, but don’t realize that all birds of prey suffered. With the banning of DDT, Cooper’s Hawk populations began increasing in the late 1980s. In 1999, they were taken off of the Endangered Species List for Illinois, and now they can be seen nesting in our forested parks. A pair frequently nests along the Valley Trail at Forest Park Nature Center. They often take over an old squirrel nest and make it their own.
Another Accipiter that calls the woods home is the Sharp-shinned Hawk. This bird is smaller than the Cooper’s Hawk, but just as agile a flier with the same appetite for birds. It is sometimes hard to tell the difference by size alone. A small, male Cooper’s Hawk is only slightly larger than a large, female Sharp-shinned Hawk. One trait to look for to help differentiate these two birds is the shape of the tip of the tail. The Sharp-Shinned Hawk tends to have a square tail-tip while the Cooper’s Hawk has a rounded tail-tip. This is usually more noticeable when the bird is in flight.
As I watch the feeders at Tawny Oak, I see a large, dark colored hawk fly across the prairie. Something amongst the prairie grass catches his eye. He hovers, with fast wing flaps for a couple of seconds, and then drops to the ground, out of sight, among the tall grasses. This is the Rough-legged Hawk, a bird of prey that spends his summer catching lemmings on the Arctic tundra. They are the size of our resident, common, Red-tailed Hawk and have the same appetite for small mammals. However their hovering flight, dark-tipped tail, bold black belly and bend-of-wing patches, will tell you that this is a much different bird. An ambassador from the great, white north where the summer sun never sets. I’m glad he finds our Illinois prairie a suitable home on this winter day. His home is now frozen, and winter darkness now grips his nesting ground.
Some feel that winter drags on, and warmer weather will never return. Those who get out and experience the natural world, realize that winter will be over all too soon. Before we know it, the birds will be migrating again. There’s no time to waste for those who want to see all of the birds that are only here in winter. Embrace the winter day!