Bird of the Month: Pigeon Guillemot
By Hugh Jennings
Scientific Name: Cepphus columba
Length 13.5 in
AOU Band code PIGU
The Pigeon Guillemot (PIGU) is a member of the auk family and is about 13-1/2” long. It is generally found close to rocky shores along the Pacific Coast from Alaska to California. The genus name Cepphus is from the Greek kepphus meaning sea bird; the species name columba is from the Latin for dove or pigeon.
The breeding adult is all black except for a white wing patch and red feet(both sexes look alike). It has a pointed black bill. It resembles the Black Guillemot which is found on the Atlantic and Arctic coast, except that a wedge-shaped bar of black extends into the prominent white wing patch. The winter plumage is mostly white; upper parts are mottled dark brown with white below, and wings are blackish with a white patch.
Both guillemots have a "water dance" in the spring in which pairs sometimes gather on the water near the nesting colony for a mutual display, calling and showing off the red linings of the mouth. They will form lines on the water for a few seconds which suddenly break up when the whole party dives with individuals chasing each other below the surface, while floating on the surface.
Its diet consists of small fish and marine life, such as shrimp, crab, worms, mollusks and small octopus. It forages by swimming underwater propelled mainly by its wings. It uses its feet mostly for steering, but also for some propulsion. It feeds mostly within 50 ft. of the surface, but can dive to 150 ft.
Pairs nest alone or in small colonies of up to 50 pairs. The nest site is in crevices, in caves or in talus slopes at the foot of cliffs on rocky islands near salt water. It even uses abandoned burrows of puffins, under railroad ties and in burrows in clay banks in the Puget Sound region of Washington, where it digs its own burrows, sometimes in banks 200 ft. above the sea. The same nest site may be used for many years. The nest is a shallow scrape in a pile of dirt, pebbles, or shells. There are only 1 or 2 eggs, creamy to pale blue-green with gray and brown blotches concentrated near the large end. Incubation is by both sexes for 26-32 days.
Both parents fed the young, bringing them small fish. The young leave the nest 29-54 days after hatching, usually at night, scrambling or fluttering down to the water. They are able to swim and dive immediately, but are not capable of strong flight for another 2-3 weeks.