Common Raven

Common raven (Corvus corax).

NPS/Kent Miller

The deep, resounding croak of a common raven (Corvus corax) echoes in high mountain, desert, forest, tundra, and coastal habitats across the Northern Hemisphere. Indeed, this largest of the songbirds (Passeriformes) comprises 10 subspecies across North America, Europe, Asia, and North Africa—an astonishing geographic range. Like its jay, crow, and magpie relatives in the corvid family (Corvidae), it is remarkably adaptable.

Glossy black plumage covers the adult raven’s entire body, being slightly duller and browner in younger birds. Its deep call, large, stout bill, and wedge-shaped tail in flight distinguish the raven from the similar looking but smaller American crow (Corvus brachyrhynchos). Long, erectable feathers (hackles) on the raven’s throat also help distinguish the two. With its 1-meter-plus wing span and frequent soaring, the raven is sometimes confused with similarly sized soaring hawks, though the raven’s long pointed bill is a dead giveaway.

Raven in flight. Note wedge-shaped tail.

Frank Lospalluto

Habitat

Ravens occur year-round in a wide variety of landscapes wherever food and a suitable nesting platform can be found. While they prefer uninhabited areas, they also occur in rural and urban areas with steady food supplies, such as garbage dumps.

Diet and Foraging

Surviving in many different habitats means eating many different kinds of food. The omnivorous raven is a master forager, from scavenging carrion to taking live prey to eating arthropods, grains, and fruit! Mammals dominate their prey, and the indigestible bits, such as fur and bones, are expelled as pellets, similar to raptors. Ravens attack rock doves in flight, steal nestlings out of nests, and follow wolves to carcasses. They’ve even been known to investigate gun shots during hunting season, presumably for clues to a fresh carcass, while ignoring similarly loud sounds not tied to food. Ravens learn from each other and from watching other raptors where to find food. These adept foraging skills have landed ravens in ill-favor with humans when the prey are species of conservation concern, such as desert tortoise (Gopherus agassizii) juveniles, or the eggs of the least tern (Sternula antillarum). Like all corvids, ravens cache food, usually in the ground. But they do it furtively, knowing that other ravens may be watching as closely as they watch their fellow stashers.

Behavior

Ravens have a vast repertoire of vocalizations thanks to local dialects and individual variation. Loud raspy begging calls of the young, adult croaks to signal location or territoriality, predator alarm calls, and female knocking (rattle) calls are some of the many distinct calls with a known function.

Have you ever watched a raven playing in the wind? Dives, rolls, and loops make for aerobatic drama year-round, especially in spring.

Ravens are generally solitary or in pairs, but they do gather at concentrated or semi-permanent food sources. Some even roost communally at night (primarily nonbreeders) in groups thought to actively share information.

Folklore ties ravens to bright shiny objects, for good reason. Young ravens actively investigate a wide variety of objects near the nest for edibility. One study introduced fledglings to new objects daily in their nest area and found that they strongly preferred objects they had never seen before, a trait known as neophilia. This ability to identify edible food, in whatever form, along with clever foraging skills, no doubt contribute to the raven’s adaptability.

Reproduction

Ravens are likely monogamous. Pairs roost together year-round and preen each other’s feathers (allopreening). Ravens nest annually, starting at 2–4 years of age. In late winter, a pair steps up courtship displays and territory defense. They build a stick nest (40–153 cm [15–60 in] wide) lined with soft material, such as mud, fur, or shredded bark, typically in a tree or on a cliff ledge, though also on power-line towers, telephone poles, and other infrastructure. The female lays an average of 5 ovate, green to olive or blue eggs with variable markings. After almost 3 weeks the eggs hatch into nestlings that will fledge in 5–7 weeks.

Fun Facts

• A group is called an “unkindness” of ravens.

• Raven intelligence studies have shown their ability to “count” to seven and do advanced problem solving (see Learn More).

Where to See

Corvus corax is common in all Klamath Network parks and breeds in most of them.

Learn More

https://www.allaboutbirds.org/news/similar-species-crows-and-ravens/

https://www.scientificamerican.com/article/young-ravens-rival-adult-chimps-in-a-big-test-of-general-intelligence/

Download a pdf of this article.

Prepared by Sonya Daw
NPS Klamath Inventory & Monitoring Network
Southern Oregon University
1250 Siskiyou Blvd
Ashland, OR 97520

Featured Creature Edition: January 2023

Thumbnail image credit: NPS/Jacob W. Frank