The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook Columbia Gazetteer American Heritage Coll. They float lower in the water than do ducks, and at the approach of danger they sink progressively lower and then submerge, a practice which has given them the name helldiver. Many grebes cover their eggs with refuse when they leave the nest, and some carry the young on their backs.
Grebes have complex courtship rituals, including dancing in pairs on the water.
They eat crustaceans, fish, and aquatic insects and plants. Unique among birds is their unexplained habit of swallowing feathers. Other grebes are the western and Holboell's grebes of North America and the eared and horned grebes of North America, Europe, Asia, and Africa. There is a flightless species in South America. Grebes were formerly hunted for their silky breast feathers.