Several members of the corvid family are common throughout San Mateo County, these include the American crow (Corvus Brachyrhynchos) and the common raven (Corvus corax). Crows and ravens are both large birds with shiny black feathers. However, with close observation they can be easily distinguished.
Ravens are larger and have a heavier beak, and their feathers look shaggy, especially around their throats. Ravens usually live alone or in pairs, and make a variety of croaking calls.
Crows are smaller and slimmer, with smooth feathers. They often live in large family groups, and make cawing noises.
Both crows and ravens will raid open compost and garbage bins if given the chance. Crows may also create a nuisance by congregating or roosting in large groups, where their droppings may deface or damage vehicles and structures.
The District does not provide bird abatement services. However, most problems with crows and ravens can be solved by limiting their access to food sources and/or eliminating their roosting areas. You may also find this information from the Washington Department of Fish and Wildlife helpful.
Crows, ravens, and other related species play an important role in the West Nile virus transmission cycle. More information can be found here.