By Tracie Hornung
Rowena Wildlife Clinic received a raven last summer, still with blue eyes – an indicator that it was a juvenile. It had fledged with a non-functional, flaccid left wing. The clinic vet, Dr. Jean Cypher, thought the problem could have been the result of nerve damage, possibly a nest injury.
The teenage raven spent the fall and winter in the comfort of a clinic aviary, eating well, slowly regaining the use of its wing, and growing into a beautiful and healthy adult. The bird improved to the point that it could fly back and forth in the 50-foot flight pen. Over the last few months it began, as is typical of ravens, to destroy the aviary apparently just for fun. The raven enlarged all the holes around tree branches, pecked and peeled away the Coroplast ™, and hollowed out grooves in plywood.
Ravens in the nearby woods were obviously aware that one of their own was living in the aviary and frequently called out to the captive. Early this spring, when Dr. Cypher determined that the young adult was ready to be released, she opened the door of the aviary to let the bird leave whenever it was ready. It frequently hopped out, surveyed the scene awhile, then returned inside.
Its newly acquired raven friends repeatedly called out to the bird. Still, day after day for three weeks, the raven didn’t budge. Who knows what it was thinking. But because ravens are among the smartest birds, it might have been using that time to watch those noisy, big, black birds and deciding if it was safe to leave its secure home and join them.
Finally, the raven made its decision – and took wing! For a week there was no sight of it. But then the raven returned. Dr. Cypher says she thinks it hasn’t figured out too well how to find food yet.
“He seems pretty eager to return for a rat handout or a bit of dog chow. Glad he’s hanging around if he needs a little boost.”
The raven species that occupies a vast year-round range in North America is known as the Common Raven. However, other than its proliferation, it is anything but common.
It is the brain in that species that I find most fascinating. (Although their beauty and impressive wingspan – almost 47 inches – are nothing to sneeze at.)
Cornell University’s All About Birds website notes that ravens are able to put together cause and effect, citing a study done in Wyoming. During hunting season the sound of a gunshot drew ravens to investigate a presumed carcass, whereas the birds ignored sounds that are just as loud but harmless, such as an airhorn or a car door slamming.
Ravens’ intelligence, combined with their predatory nature, makes them extremely dangerous to other species – and even their own. (Dr. Jean is caring for another raven that was the victim of assault by other ravens. During one of the last snowfalls of winter, the raven was found nearly dead under several other ravens. They had pecked out its left eye, and the victim was thin, and had bruising and small scratches all over. Dr. Cypher says she wonders if the birds were food-stressed in the late winter, and were getting ready to kill and eat the victim. She continues to care for the raven, which is understandably a shy fellow. It’s only now starting to hop around the clinic, and its prognosis is uncertain. )
Much like wolves and orcas, ravens work together to hunt, alerting each other to prey or distracting a parent while the other raven nabs its egg or baby. Decreases in the populations of vulnerable species such as desert tortoises, Marbled Murrelets, Least Terns and sage grouse are attributed in part to increases in raven populations. (The Idaho Times-News recently reported on a controversial Idaho state plan to poison ravens to reduce the number of sage grouse kills.)
No doubt the imbalance in raven populations derives, as in most cases of species imbalances, to an overall ecosystem problem. For whatever reasons their population numbers are strong, ravens are considered by the International Union for Conservation of Nature (IUCN) a species of least concern.
So the good news is that for the foreseeable future we don’t have to worry, when we wander through the forest, of losing sight of ravens or the aural rapture of hearing one or more of their 30 different calls. To hear some of them now, visit All About Birds.