American Crow – Corvus brachyrhynchos
Length: 17.5″; Wingspan: 39″; Weight: 16 oz.
Fish Crow – Corvus ossifragus
Length: 15″; Wingspan: 36″; Weight: 10 oz.
Probably many people on Seabrook have no idea that there are two kinds of crows here. For most of us, a crow is a crow. Actually there are two different species on the Island: the American Crow and the Fish Crow. They look so much alike that even the pros find it difficult to distinguish between them but there’s one fool-proof way.
Both crows are very big and black. In general, the Fish Crow is slightly smaller: its beak, its legs and overall. Their ranges of size overlap, however, and those differences are hard to establish in the field. So, size alone is not a safe way to differentiate them
An easier characteristic that is sometimes used to distinguish the two crows is their stance when they call. The Fish Crow often fluffs its feathers, particularly around its neck. The American Crow remains smooth. Note the two pictures below.
To be sure of an identification, however, you have to use your ears. Most people are familiar with the loud Caw Caw sound of the American Crow. The Fish Crow has a similar call but it sounds as though he has a cold. It’s very nasal. He also has a two-note call that sounds as though he is responding negatively to a question: Anh Anh.
Crows seem to be everywhere, both singularly and in small groups. They eat a great variety of foods, both animal and vegetable. This includes normal examples as well as carrion, trash, nestlings and eggs of other birds. Their dietary flexibility is one of the reasons they are so successful in so many different habitats which is also why they seem omnipresent.
Crows are very social birds, sometimes forming very large flocks in the hundreds. They are noted for being very intelligent with problem-solving capabilities. Some live into their teens in the wild; the oldest recorded in captivity died at 59 years old.
Crows are noisy birds in general. Occasionally several may join together and make an even larger racket than normal. This can be an example of mobbing which occurs when a group of crows deliberately pester a larger bird, usually a bird of prey such as a hawk or owl. They may even dive bomb the “enemy”. This behavior is not totally understood but it is assumed that the attackers are attempting to force the predator to move on. If you watch, you may see the predator suddenly take flight with the crows in pursuit squawking as they go.
If you would like to learn more about these birds visit:
- The Cornell Lab of Ornithology – All About Birders: American Crow
- The Cornell Lab of Ornithology – All About Birders: Fish Crow
Article submitted by: Marcia Hider
Photographs provided by: Bob Hider & Charley Moore
This blog post is part of a series SIB will publish on a regular basis to feature birds seen in the area, both migratory and permanent residents. When possible we will use photographs taken by our members. Please let us know if you have any special requests of birds you would like to learn more about.