The American crow (Corvus brachyrhynchos) is commonly seen year-round in Frederick County. In winter the "caaw, caaw, caaaw" sound seems louder with the leaves down, as the crows communicate among themselves to identify food or danger.
The crow is all black, about 16 to 20 inches in length, and is a protected migratory bird. In winter the crows' diet turns to scavenging for nuts, acorns and any remaining seeds and berries. Winter crows also eat carrion and will raid bird feeders and compost areas.
They typically travel in groups of a half-dozen or more to feed, with a couple of the birds remaining posted in surrounding trees to look out for predators.
If it seems there are fewer crows in this area than in years past, it may be due to the crows' sensitivity to the West Nile virus. As a sentinel species for West Nile, crows succumb more rapidly than other species to the virus. They are not known to transmit the disease to humans.
Crows reach maturity in two years, and they are known to mate for life. Mating takes place on the ground in late winter. Both parents participate in raising the young. Their nests can be found built of sticks about a foot in diameter, high in a tree, typically 20 to 60 feet from the ground. Producing one brood per year, from two to six eggs, the fledgling crows start leaving the nest at 5 weeks of age.
It is interesting that crows are known to recognize individual humans.
Article by FCFCDB
Nature Notes for 2/6/2011