November 2021 - American Crow
What group of birds is called a "murder?"
It is the American Crow. The crow is a large black bird, with long legs, a thick neck and a heavy straight bill. And by black, we mean all black--feathers, bill, eyes, legs, everything. When seen in flight, the wings are broad and the wingtip feathers look like fingers. The tail is rounded or square at the end. A crow is double the size of a blue jay and about two-thirds the size of a raven. The American Crow along with the Common Raven, Yellow-billed Magpie, California Scrub Jay and Steller's jay are members of the genus "Corvus." More than 40 species are in this genus living in every continent except South American, Antarctica and some Pacific Islands. Crows are omnivores, eating just about anything. They will eat earthworms, insects, grains and seeds, berries and fruits. Some small animals are on the menu such as mice, and yes, sometimes they take eggs and baby birds from nests of robins, jays and sparrows. Crows may follow adult birds to locate the nest. They will also steal food from other animals. Crows also eat fish, young turtles, mussels and clams. Road kill is a small part of their diet but they need to wait for help to eat it. Someone else needs to open the body or the body needs to decompose to make it easy for the crow to tear the flesh. Their beak isn't strong enough to tear open a dead animal. They build a nest in a crotch near the trunk of an evergreen tree. Both parents build the nest sometimes with the help of the juveniles from the previous year. (Juveniles may stay with the parents for a few years while they try to find a place of their own.) Twigs shape the nest and the nest is lined with pine needles, weeds and soft bark. This is not a small nest. It can range from 6-19 inches across and 4-15 inches deep. Three to nine eggs are laid in the nest and take 16-18 days to incubate. The young are born naked with a few tufts of gray down and with closed eyes. They stay in the nest for 20-40 days. Crows are very social. Rarely will you see a single crow. They roost and forage in large groups. Crows roost in winter in groups that may number in the hundreds of thousands. When roosting at night, it is thought that crows share information about sources of food and work out solutions to problems. Crows are among the smartest animals in the world and are considered as intelligent as the chimpanzees. Crows know how to use tools. They will dip a cup in water and use it to moisten dry food. Or rip off a splinter of wood from a fence for spearing and pulling prey from a hole. Distinguishing a crow from a raven can be difficult. "Field marks" are unique and easily-seen characteristics used to identify a bird. For these two, the tail of a crow is distinguished from a raven as it is rounded or squared where a raven's tail is wedged shaped. Their calls are also different. The crow sounds like "caw" and the raven's call is deep croak. If possible, size helps as well since ravens are larger than crows. Their "caw" can be varied to communicate danger, keep their family members on the alert, share new sources of food, and even announce a stranger is nearby. They are noisy, except when near the nest. Here they are quiet to keep the young safe. The oldest wild crow was photographed in Washington State and was at least 17 years 5 months old. In captivity, a crow in New York lived to be 59 years old. Tri County Wildlife Care, a local nonprofit started in 1994, is dedicated to the rescue and rehabilitation of our native wildlife and helping our community live in balance with wildlife. They envision a world where wildlife and people thrive together. For more information call (209) 283-3245, or visit pawspartners.org. |
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