Rhinoceros Auklet

Cerorhinca monocerata

Rhinoceros Auklet

Cerorhinca monocerata

Other Common Names
Rhino auklet, horn-billed puffin, unicorn puffin

Seabird Aviary

Other Common Names

Rhino auklet, horn-billed puffin, unicorn puffin

At the Aquarium

Seabird Aviary

Appearance

As its name might suggest, this bird has a ‘horn’ on its bill, growing annually in the early spring and shed in late summer. Individuals in breeding plumage have brownish gray backs and chests while their bellies are lighter in color. The rhinoceros auklet has a yellow-orange bill and four white plumes on its head, one above and one below each eye. Plumes refer to an arrangement of decorative feathers, often larger and more elaborate than typical feathers used for flight.

In non-breeding plumage the plumes are absent or reduced and the bill is duller in color. Juveniles look similar to non-breeding adults but lack plumes on their head and have a smaller darker bill.

Habitat

Offshore and shorelines and islands

Diet

Fish and invertebrates such as squid and krill

Life History

In the winter the rhinoceros auklet remains in waters offshore from breeding areas and sometimes in nearshore coastal waters where food is more concentrated. Summer and winter ranges overlap in many areas, but many rhinoceros auklets leave the northern part of their breeding range and migrate south in the winter.

This species occurs in large groups at sea, commonly forming roosting flocks at night in sheltered bays during the winter. The rhinoceros auklet joins colonies in late March and early April to breed, laying eggs from the end of April to mid-June.They breed on maritime and inland grassy slopes, as well as on islands away from predators. This species lays one egg in nests at the end of a burrow which is created and maintained by both males and females.

Eggs are white and usually spotted with brown and gray. Both males and females incubate the eggs. This incubation period lasts 39 to 52 days. Young rhinoceros auklets leave the nest about 7 to 8 weeks after hatching.

IUCN Status

Least Concern

Ecosystem & Cultural Importance

As predators, rhinoceros auklets help regulate populations of fish and invertebrates. They are also food sources for a variety of other species. Eggs are often preyed upon by Keen’s mice and common ravens. The rhinoceros auklet holds cultural significance for the Haida and Tlingit indigenous peoples.

In the North Pacific, breeding occurs from California, off the coasts of Canada and Alaska to the Aleutian Islands. Also found on the Hokkaido and Honshu islands of Japan, as well as on the northern tip of North Korea, Sakhalin island in Russia and at two locations on the far eastern Siberian coast.

The rhinoceros auklet nests in small numbers in Oregon. Goat and Hunter Islands have the largest population of breeding rhinoceros auklets in Oregon.

Despite appearing clumsy during takeoff, the rhinoceros auklet is a fast flier and may travel long distances to feed. This species forages for food while swimming underwater and can remain submerged for up to 2 minutes!

Citations & Other Resources

BirdLife International. 2018. Cerorhinca monocerata. The IUCN Red List of Threatened Species 2018.
National Audubon Society. N.d. Rhinoceros Auklet. Audubon Field Guide.
Oregon Department of Fish & Wildlife. N.d. Rhinoceros Auklet.
Alsop, F. 2001. Birds of North America (1st American ed.). DK.
Hayward, J. L., G.J. Atkins, A.A. Reichert, and S.M. Henson. 2015. Common Ravens (Corvus corax) Prey on Rhinoceros Auklet (Cerorhinca monocerata) Eggs, Chicks, and Possibly Adults. The Wilson Journal of Ornithology, 127(2), 336–339. https://doi.org/10.1676/wils-127-02-336-339.1
Blight, L. K., J.L Ryder, and D.F. Bertram. 1999. Predation on Rhinoceros Auklet Eggs by a Native Population of Peromyscus. The Condor (Los Angeles, Calif.), 101(4), 871–876. https://doi.org/10.2307/1370079
MOSS, M. L. 2007. HAIDA AND TLINGIT USE OF SEABIRDS FROM THE FORRESTER ISLANDS, SOUTHEAST ALASKA. Journal of Ethnobiology, 27(1), 28–45. https://doi.org/10.2993/0278-0771(2007)27[28:HATUOS]2.0.CO;2

Rhinoceros Auklet

Rhinoceros Auklet

Other Common Names

At the Aquarium

Appearance

Habitat

Diet

Life History

IUCN Status

Ecosystem & Cultural Importance

Citations & Other Resources

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