Bird Lore: Pelagic Cormorant

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The Pelagic Cormorant is common along the Edmonds waterfront. Individuals rest communally during the day on the dolphins at the ferry dock but they are solitary when swimming and diving. It is the smallest cormorant along the West Coast and is noticeably smaller than the larger, and also common, Double-crested Cormorant. (Read more about the Double-crested Cormorant at this link.)

On the ocean, the Pelagic Cormorant usually stays close to shore. It favors rocky bays and areas of deep water near the base of cliffs. Unlike the Double-crested Cormorant, the Pelagic Cormorant usually is not found away from marine waters. It eats mainly small fishes such as herrings, sculpins, greenlings, and sand lance. It also feeds on crabs and shrimps, as well as marine worms, amphipods, and algae. It is solitary when it feeds and does so by diving from the surface and propelling itself underwater by its feet. It can dive as deep as 120 feet and usually finds its food near the bottom in rocky areas.

The Pelagic Cormorant nests in loose colonies, usually on cliffs with near-vertical slopes and narrow ledges, facing to sea. It has also been known to nest on navigation buoys, navigation towers, and abandoned piers. Nest sites in Washington have included the cliffs at Cape Disappointment, and at Paahwoke-it, Tatoosh, Protection, Smith, and Colville and Castle Islands. Very few nests have been found in Puget Sound.

The male engages in courtship displays at the nest site. He will point his bill upward, his tail downward, and will quickly raise and lower the tips of his folded wings so that his white flank patches appear to flash rapidly. The adults are ineffective at defending their nest or their young, so this species relies on an inaccessible location for protection. Both sexes build the nest of mostly seaweed, grass and moss. Sometimes sticks are added to the nest and it can even contain general marine debris such as rope and plastic. This cormorant uses its own guano to solidify the nest materials and to anchor the nest to a cliff face.

Both adults incubate the 3-5 eggs for 26-37 days. They both probably feed the chicks, which are capable of short flights at 35-40 days of age. Although great variation has been observed, the nestlings usually fledge at 45-55 days of age. The adults may continue to feed the young birds for another few weeks.

The Pelagic Cormorant is the least social of the cormorants. Although it is often solitary, collective nouns for all cormorant species include gulp and flight. Gulp is an apt noun, based on the way a cormorant swallows prey such as fish. You can see the prey bulge its way down the elongated throat in the third photo. The oldest Pelagic Cormorant of record was 17 years and 10 months of age when it was found in British Columbia.

There are an estimated 69,000 breeding birds in the Pelagic Cormorant global population. Although the population appears to have declined between 1966 and 2014, the species is of low concern for conservation purposes. This is puzzling because it is listed as a species of high concern in the North American Waterbird Conservation Plan. Historically, all cormorant species have been killed, disturbed, and have had their nests and eggs destroyed by fishermen who believed that cormorants eat commercially valuable fish. Even the U.S. Fish and Wildlife Service has destroyed cormorants. Studies in British Columbia and Alaska have demonstrated that marine cormorant species predominantly feed on coarse fish that are not harvested by commercial fisheries. The Pelagic Cormorant is vulnerable to marine pollution and human disturbance near nest sites.

We don’t usually hear vocalizations of Pelagic Cormorants around Edmonds. However, there can be a lot of vocalizing as many birds arrive at a night roost. You can listen to group communication at a winter night roost in British Columbia here: https://www.xeno-canto.org/209340.

— By Carol Riddell

Carol Riddell, author of our new “Bird Lore” feature, manages the bird education displays, on behalf of Pilchuck Audubon Society and Edmonds Parks & Recreation, at the Olympic Beach Visitor Station.

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