Wednesday, July 30, 2008

Know your corvids.

By my reckoning, there are about 4,000 Northwestern Crows in our city (I have no idea; I pulled that number out of a hat – point is, there are many, many crows), and maybe a dozen Common Ravens (not sure about that number either, but despite the name they're not common). In certain places, such as the neighbourhood around Paulik Park on Heather Street with its acre or two of towering spruce, cedar and Douglas fir, you hear ravens all the time. They are not quiet birds, producing low-pitched croaks, ringing bell-like notes, and sore-throated squawks. Mostly, when not talking to each other, they are swearing at the crows.

How do you know you’re seeing a raven, not a crow? When they’re side by side the obvious difference is that the Common Raven is a lot larger (beak to tail 24,” wingspan 53," mass 2.6 lb. vs. 16,” 34,” 13 oz. in Northwestern Crow -- values from D. A. Sibley Field Guide to the Birds of Western North America).

Raven on the roof (of the local mall).

The Raven also has shaggy throat feathers, a somewhat “Roman-nosed" bill, and the crown of the head is more high-domed.

Raven, Corvus corax, being heckled by Northwestern Crow, Corvus caurinus.

In flight, the wings of the Common Raven are proportionally longer and narrower than in the crow, and the shape of the tail is distinctly different. It is diamond-shaped, the posterior margin forming a wedge, whereas the tail of the crow has a gently rounded posterior margin.

And another thing: it is usually the crow chasing the raven, which seems never to end. It must be tiresome being a Common Raven in the world of the much more common Northwestern Crow.


chey said...

Very interesting! I've seen that chase happen many times. I've always thought that it was the crow who was being chased. Now I'll be watching more closely. Thanks for pointing out some of the differences between ravens and crows.

kompoStella said...

yes, thanks for the facts, i'll refer people to your explanation - most cannot tell the difference. although i'm fascinated with the raven - it's nature and all the myths and folklore surrounding it - i find that all black birds is a joy to watch against the sky.

Anonymous said...

Very helpful, thanks. I good reminder of things I read once but don't routinely recall.

justducky said...

We live in Northern California in raven country. The adventures I've seen from the last 25 years!