1. The region of feathers around the cloaca of a bird, located between the tail and the belly.
Usage: ornithology; technical

Examples

• Birdwatchers use the color and pattern of the crissum to help identify different species.
• The crissum of the robin displays distinctive white spots that aid in field identification.
• Ornithologists examine the crissum closely when cataloging plumage characteristics.
• The crissum feathers are often fluffed during preening behavior.
• In many warbler species, the crissum coloration differs from the rest of the underparts.