Rhinoceros Auklet

Media Player Error
Update your browser

Rhinoceros Auklet by Liron Gertsman / Macaulay Library

Auks

Rhinoceros AukletCerorhinca monocerata

ORDER: Charadriiformes
FAMILY: Alcidae

Basic Description

The squat, grayish Rhinoceros Auklet is a close relative of puffins, although it doesn't sport quite such a fancy bill. Still, its name refers to the single vertical horn that sticks up from its orange bill—an odd accessory that turns out to be fluorescent and may be used for visual communication. These seabirds are fairly common along the Pacific Coast of North America, where they hunt close to shore for small schooling fish, pursuing them by "flying" underwater with strong wingbeats.

More ID Info

image of range map for Rhinoceros Auklet

Year-roundBreedingMigrationNonbreeding

Range map provided by Birds of the World

Explore Maps

Find This Bird

Rhinoceros Auklets are fairly common breeders in Pacific waters from southeastern Alaska to Washington, and are seen farther south during the nonbreeding season. They can be common sights during whale-watching tours in Puget Sound and the Salish Sea of Washington/British Columbia, as well as in Monterey Bay, California. Dedicated "pelagic" (offshore) birding trips are also likely to find the species. They're sometimes even seen from shore when following schooling prey, so patient scanning of the ocean (ideally with a spotting scope) can turn up a few.

Other Names

Alca Unicórnea (Spanish)
Macareux rhinocéros (French)

Cool Facts
- The purpose of the Rhinoceros Auklet's horn (technically part of the bill) has always been something of a mystery. But in 2019, research revealed that it's fluorescent. Although it looks grayish to us, the horn is brightly colored for animals that can see ultraviolet (as Rhinoceros Auklets can). This feature might help Rhinoceros Auklets see each other underwater when foraging or at night at their breeding colonies.
- Rhinoceros Auklets are closely related to puffins—and in the past they have been known as Horn-billed Puffins or Unicorn Puffins.
- The Rhinoceros Auklet, like puffins, can catch fish, hold on to them in its bill, and then go on catching more fish without losing hold of any of the slippery prey. This is thanks to special spikes in the rear of the upper jaw called palatal denticles. Other alcid (auk) species such as murres and guillemots can carry only one fish at a time.
- The Rhinoceros Auklet is the sole living member of its genus, Cercorhinca. In earlier times, during the Miocene and Pliocene epochs, at least five other species of this genus roamed the seas.
- The Rhinoceros Auklet bred on the Farallon Islands off California in the early 1800s but vanished in the 1860s, then reappeared there in the early 1970s. The reason for this hiatus is not known.
- The Rhinoceros Auklet delivers food to its nest site largely by night. This behavior may be an adaptation to keep gulls and other species from stealing its food.
- The oldest recorded Rhinoceros Auklet was at least 28 years, 3 months old. It was banded in 1984 in British Columbia and found in Oregon in 2010.