Wednesday, February 9, 2011

Not only found in the hall of the Library of Congress

Nature Watch

By Susan Thurn,
Cable Natural History Museum

How does a cooper’s hawk end up in the main hall of the Library of Congress? Is the bird stopping in for a library card? Reading a book is indeed one of the best things, after all! This is also an amazing library, with 32 million books and materials in 470 languages! Could it instead be chasing a meal indoors? The Cooper’s hawk is indeed one of the birds that can be enjoyed not just in one of the most amazing libraries in the world, but also in the north woods.

The Cooper’s hawk is a smaller hawk, quite colorful with red eyes, a dark gray back, and rusty bars on its breast. This hawk is very similar to the sharp-shinned hawk, making it very difficult to tell between the two species. When in flight, Cooper’s have stiff wingbeats with short glides. In hunting, they are quite skilled.

A very skilled flyer, Cooper’s hawks move through tree canopies in woodland habitats. They are often in high speed pursuit of medium sized birds. Some of their preferred dinners include the starling, mourning dove, pigeons, robins, grouse, flickers, and jays. They will also eat chipmunks, squirrels, mice, and even bats, although the western Cooper’s hawk more commonly eats mammals. They also rob nests for eggs. They can eat up to 12% of their own weight in one day. For a 200 pound person we would have to eat 24 pounds of food each day!

Cooper’s are also sometimes unwanted guests at our bird feeders, searching for an easy menu of birds rather than bird seed. When they capture their prey, the hawks use their feet and kill it with repeated squeezing. They also have been observed drowning their prey underwater until it stops moving.

Our north woods Cooper’s hawks prefer dense evergreen or deciduous forests. They spend our winters as migrants in Central America – Ahh, a summer in the northwoods followed by a winter in the warmth of the south. However, this lifestyle may not always be an easy one. A study of over 300 Cooper’s hawks showed that nearly 25% of them had evidence of healed bones, a result of swift flight through a rather challenging forest habitat. Perhaps getting a library card would seem easier! Actually, Cooper’s hawks have become much more common in urban areas, as cities provide them with plenty of pigeons and mourning dove prey.

Visitors to the Library of Congress were lucky to have a lovely view of one spectacular bird. The Cooper’s hawk is indeed a gem, and one we are lucky to share our homes with as well!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its new traveling exhibit in February, "In a New Light" photography exhibit, in Cable at 13470 County Highway M. Also find us on the web at to learn more about our exhibits and programs.

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