corvids
Since moving to far northern California, I’ve been courting the local beach ravens and they have proven very cooperative subjects. There is a lot to commend these enormous songbirds to the interested observer. They are extremely intelligent, to the point of using and even crafting tools. They are very socially complex among themselves but also have the ability to recognize individual humans by their faces and communicate that information with their kin. They are, like us, profoundly successful, opportunistic omnivores who can thrive in hot deserts, in some of the coldest places in the world and most everywhere in between. Ravens feature prominently in mythology and folklore where their cleverness was recognized by our ancestors all over the world before we ever had a way to quantify it. They are known to cooperate with hunters, both wolf and human, leading the hunters to herds of unseen prey animals that the ravens might benefit from the spoils of the hunt.
More words below, but first, pictures.
A common raven.
A common raven with an unusually pronounced hook at the end of their beak.
Liftoff!
A common raven in flight.
A pair of ravens.
A pair of ravens, one displaying dominance by fluffing their hackles.
These two are planning to use this photo for their holiday card.
It's not uncommon for ravens to show affection by touching beaks.
Note the distinctively thick beak and soft rictal bristles at the base on top and bottom. On the top, you can see the outline of the nares (nostril) under the naked feather shafts that form the bristles.
They observe me every bit as much as I observe them.
A raven in flight.
Distinguishing Ravens from Crows
To the untrained eye, it can be very difficult to tell a common raven (Corvus corax) from an American crow (Corvus brachyrhynchos). In truth, the distinction between what we call crows and what we call ravens is one of convention. They are closely related species of the same genus and we simply call the large ones ravens and the smaller ones crows. That being said, once we recognize that we’re the ones putting them in the boxes, crows and ravens can be distinguished in a variety of ways.
The most obvious physical characteristic is that ravens are much larger than crows - usually about twice as large with wingspans stretching up to 150cm (~5 feet), similar to that of a red-tailed hawk. This fact is helpful when they are side by side but less so in most cases because they tend to be mutually antagonistic and don’t usually hang out together. That said, if you see a big black bird and think “holy shit, that’s a really big bird”, it’s almost certainly a raven.
The raven has a massive beak. Truly, it’s like a beak with a bird attached to it. They tend to hook down a bit more at the tip, sometimes extremely so as in one of the photos above.
The central tail feathers of a raven are somewhat longer than the rest. This can give them more of a wedge shape when they are fanned out in flight. Crows, with uniform length tail feathers, tend to have a more gentle “C” shape in flight. Ravens are also far better equipped for soaring than crows who tend to be flapping their wings if they are flying.
Ravens have very long feathers around their neck called hackles. These can be articulated in display as seen above. Like all corvids, they have soft rictal bristles at the base of the beak that cover their nares (nostrils), but those of the raven are particularly pronounced. You can make out the outline of the nares in one of the profile photos above.
Unless you’re trained to do so and holding the animal in your hands, you’re unlikely to be able to tell a male from a female crow or raven. They exhibit minimal sexual dimorphism, with males on average being slightly larger than females. They form long-term pair bonds and raise chicks together year after year though the females tend to do most of the nest building which might offer clues if you happen to observe that particular behavior. Juveniles have bright pink mouths to tell mom and dad “FOOD GOES HERE” that blacken with maturity and social dominance.
Ravens and crows sound very different from one another. Crows tend to repeat the same grating “caw” and they do it a lot whether perched or flying. The raven’s common “caw” is a lower and less abrasive “croak” and while they tend to talk a lot less than crows, especially in flight, and they have a far wider variety of vocalizations including the ability to mimic human speech. I’m working to create some field recordings of these sounds with a home-made parabolic dish antenna and I’ll post the results here at some point.
Geographically, crows tend to be found in cities. They thrive in human constructed habitats and can flock in the thousands as they do in Portland and Seattle. Ravens tend to be found in more rural areas, pasture lands, and forests. Large flocks of crows will harass ravens and push them out of their territory.
Some resources:
A researcher with a wonderful talent for science communication, Dr. Kaeli Swift keeps a blog on corvid research, parts of which I have linked to above. She has since moved away from studying crows but there are some wonderful resources there.
The Cornell Lab of Ornithology is a wealth of information but in particular, I credit the Merlin Bird ID app with really jump-starting my interest in bird watching.
There are many excellent books on corvids generally and ravens in particular. Here’s a few of my favorites:
Mind of the Raven - Bernd Heinrich
Ravens in Winter - Bernd Heinrich
I’m a big fan of podcasts. I love absorbing information while my body is otherwise occupied. Here’s a few specific episodes that I found particularly enjoyable or enlightening.
Ologies - Corvid Thanatology (CROW FUNERALS) with Dr. Kaeli Swift
Beaver State Podcast - Crows and Ravens with Dr. Kaeli Swift
Voices of Greater Yellowstone - Ravens: Yellowstone’s Clever Corvids