Common Raven
Corvus corax
Common Ravens are impressive, highly intelligent birds found throughout Oregon, particularly in more open and wilder landscapes, including mountains, deserts, coastlines, and even venturing into some rural and suburban areas. They are often distinguished from American Crows by their larger size, wedge-shaped tail (crows have fan-shaped tails), shaggier throat feathers, and deeper, more varied vocalizations (often a guttural "kronk" or "gronk" instead of a sharp "caw").
However, like American Crows, Common Ravens are **sexually monomorphic**. This means that male and female Common Ravens look virtually identical in their plumage and overall appearance. Both sexes are entirely iridescent black, with a robust build, thick bill, and shaggy throat feathers.
Therefore, for the casual observer in Oregon, visually telling a male from a female Common Raven is extremely difficult, if not impossible, without specific behavioral cues or specialized scientific methods.
General Appearance (Both Sexes):
Plumage: Deep, glossy, all-black plumage with an iridescent sheen that can appear purplish or bluish in certain light.
Size and Shape: They are the largest passerines (songbirds) in the world. They have a massive, powerful black bill, a thick neck, and distinctive shaggy "hackles" (throat feathers) that are often ruffled during vocalizations or displays. Their tail is wedge-shaped, a key differentiator from the fan-shaped tail of a crow. Their wings are long and somewhat "fingered" at the tips in flight.
Vocalizations: Highly varied and complex, including deep, resonant "kronk" calls, guttural gurgles, whistles, clicks, and even mimicry.
Behavior: Known for their intelligence, problem-solving abilities, and complex social interactions. They are often seen singly or in pairs, though non-breeding birds and young can gather in larger groups, especially at food sources like carrion or landfills. They are also known for their acrobatic flight, performing rolls and dives.
Subtle Differences and Behavioral Cues (where distinctions might be observed):
Since direct visual identification is unreliable, behavioral observations, especially during the breeding season, offer the best clues:
Size (Slight Average Difference): While not a field mark, scientific studies have shown that males are typically slightly larger and heavier than females on average. This difference is usually too subtle to notice unless you have both sexes side-by-side for direct comparison. Males might also have slightly longer bills or wings, but again, this requires precise measurement.
Behavior during Breeding Season (Most Reliable):
Pair Bonds: Common Ravens form strong, long-term, monogamous pair bonds and are highly territorial during the breeding season. You'll often see them together as a pair year-round.
Courtship Displays: Males perform spectacular aerial displays during courtship, including soaring, swooping, and tumbling in mid-air. Pairs may also soar high together, touch bills, and preen each other's feathers while perched.
Nest Building: Both sexes participate in building their large, bulky nests, typically on cliff ledges or in tall trees (especially conifers). However, the female generally does more of the actual construction of the nest cup and lining.
Incubation: The female Common Raven is almost exclusively responsible for incubating the eggs (usually 3-7, pale blue-green with brown blotches) for about 18-21 days. During this period, the male will consistently bring food to the incubating female. This is one of the most reliable ways to differentiate them behaviorally.
Parental Care: Once the young hatch, both parents share in feeding the nestlings, which fledge at about 5-7 weeks old.
Territorial Defense: Both sexes are fiercely protective of their nest and territory, actively driving away intruders, including other ravens and potential predators.
Juvenile Common Ravens:
Young ravens generally resemble adults but may have duller, less glossy black plumage and their throat hackles might be less developed or shaggy. Their calls might also be less varied or mature.
However, like American Crows, Common Ravens are **sexually monomorphic**. This means that male and female Common Ravens look virtually identical in their plumage and overall appearance. Both sexes are entirely iridescent black, with a robust build, thick bill, and shaggy throat feathers.
Therefore, for the casual observer in Oregon, visually telling a male from a female Common Raven is extremely difficult, if not impossible, without specific behavioral cues or specialized scientific methods.
General Appearance (Both Sexes):
Plumage: Deep, glossy, all-black plumage with an iridescent sheen that can appear purplish or bluish in certain light.
Size and Shape: They are the largest passerines (songbirds) in the world. They have a massive, powerful black bill, a thick neck, and distinctive shaggy "hackles" (throat feathers) that are often ruffled during vocalizations or displays. Their tail is wedge-shaped, a key differentiator from the fan-shaped tail of a crow. Their wings are long and somewhat "fingered" at the tips in flight.
Vocalizations: Highly varied and complex, including deep, resonant "kronk" calls, guttural gurgles, whistles, clicks, and even mimicry.
Behavior: Known for their intelligence, problem-solving abilities, and complex social interactions. They are often seen singly or in pairs, though non-breeding birds and young can gather in larger groups, especially at food sources like carrion or landfills. They are also known for their acrobatic flight, performing rolls and dives.
Subtle Differences and Behavioral Cues (where distinctions might be observed):
Since direct visual identification is unreliable, behavioral observations, especially during the breeding season, offer the best clues:
Size (Slight Average Difference): While not a field mark, scientific studies have shown that males are typically slightly larger and heavier than females on average. This difference is usually too subtle to notice unless you have both sexes side-by-side for direct comparison. Males might also have slightly longer bills or wings, but again, this requires precise measurement.
Behavior during Breeding Season (Most Reliable):
Pair Bonds: Common Ravens form strong, long-term, monogamous pair bonds and are highly territorial during the breeding season. You'll often see them together as a pair year-round.
Courtship Displays: Males perform spectacular aerial displays during courtship, including soaring, swooping, and tumbling in mid-air. Pairs may also soar high together, touch bills, and preen each other's feathers while perched.
Nest Building: Both sexes participate in building their large, bulky nests, typically on cliff ledges or in tall trees (especially conifers). However, the female generally does more of the actual construction of the nest cup and lining.
Incubation: The female Common Raven is almost exclusively responsible for incubating the eggs (usually 3-7, pale blue-green with brown blotches) for about 18-21 days. During this period, the male will consistently bring food to the incubating female. This is one of the most reliable ways to differentiate them behaviorally.
Parental Care: Once the young hatch, both parents share in feeding the nestlings, which fledge at about 5-7 weeks old.
Territorial Defense: Both sexes are fiercely protective of their nest and territory, actively driving away intruders, including other ravens and potential predators.
Juvenile Common Ravens:
Young ravens generally resemble adults but may have duller, less glossy black plumage and their throat hackles might be less developed or shaggy. Their calls might also be less varied or mature.