Photo: Tom Middleton/Vireo

Rhinoceros Auklet

Cerorhinca monocerata

A chunky dark seabird, related to the puffins, common at times off the northern Pacific Coast. Often unsuspicious, and boats may approach it rather closely on the water. If pressed, it dives and swims powerfully underwater. Although its takeoff appears clumsy and laborious, it is a fast flier, and may fly long distances to feeding areas daily. The "horn" on the bill, responsible for the bird's name, grows annually in early spring and is shed in late summer.
Conservation status Not as abundant as some Arctic auks, but still fairly numerous. On Farallon Islands, California, where the species ceased to breed for almost a century, it re-established itself in the 1970s after introduced rabbits were eliminated (rabbits may have competed for burrows).
Family Auks, Murres, Puffins
Habitat Ocean, tide-rips; nests in burrows on islands. Often far from land, but may feed close to shore, especially where tidal currents near islands cause upwellings or concentrations of food. In winter flocks may spend night on coastal bays, flying farther out to sea to forage by day. Nests on islands, in burrows in soil under grass, shrubs, trees.
A chunky dark seabird, related to the puffins, common at times off the northern Pacific Coast. Often unsuspicious, and boats may approach it rather closely on the water. If pressed, it dives and swims powerfully underwater. Although its takeoff appears clumsy and laborious, it is a fast flier, and may fly long distances to feeding areas daily. The "horn" on the bill, responsible for the bird's name, grows annually in early spring and is shed in late summer.
Photo Gallery
  • adult, breeding
  • juvenile (1st year)
Feeding Behavior

Forages while swimming underwater. Can remain submerged for up to 2 minutes. May tend to forage closer to shore than puffins.


Eggs

one. White, usually spotted with brown and gray. Incubation is by both sexes, 39-52 days, average 45 days. Young: both parents feed young, carrying fish in bill to nest. Young leaves nest about 7-8 weeks after hatching.


Young

both parents feed young, carrying fish in bill to nest. Young leaves nest about 7-8 weeks after hatching.

Diet

Fish, crustaceans. Food brought to nestlings is mostly small fish, particularly sand lance, herring, and anchovy, also rockfish, smelt, saury, and others. Favors fish that gathers in dense schools. Diet of adults probably similar. Also eats crustaceans.


Nesting

Breeds in colonies, mostly on islands. Generally active around colonies only in evening and at night, although at some colonies the adults visit by day as well. Courtship displays include members of pair nibbling at each other's bills. Advertise ownership of nest site by standing upright, with wings partly opened, pointing bill up and hissing. Nest site is in burrow in ground, typically on slight slope covered with grass, shrubs, trees, sometimes in steep slope or cliff. Burrow up to 20' long, usually 5-10', with one or more side branches. Nest is in chamber in burrow, a shallow cup of moss, twigs.

Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

More strongly migratory than most western auks. Although summer and winter ranges overlap widely, mostly vacates northern part of breeding range in winter, and large numbers move into California waters then.

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Migration

More strongly migratory than most western auks. Although summer and winter ranges overlap widely, mostly vacates northern part of breeding range in winter, and large numbers move into California waters then.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon
Songs and Calls
Low growling notes.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
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How climate change could affect this bird's range

In the broadest and most detailed study of its kind, Audubon scientists have used hundreds of thousands of citizen-science observations and sophisticated climate models to predict how birds in the U.S. and Canada will react to climate change.

Learn more

Read more: climate.audubon.org
Auks, Murres, Puffins Upright-perching Water Birds

Rhinoceros Auklet

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season.

More on reading these maps.

Each map is a visual guide to where a particular bird species may find the climate conditions it needs to survive in the future. We call this the bird’s “climatic range.”

The colors indicate the season in which the bird may find suitable conditions— blue for winter, yellow for summer (breeding), and green for where they overlap (indicating their presence year-round).

The darker the shaded area, the more likely it is the bird species will find suitable climate conditions to survive there.

The outline of the approximate current range for each season remains fixed in each frame, allowing you to compare how the range will expand, contract, or shift in the future.

The first frame of the animation shows where the bird can find a suitable climate today (based on data from 2000). The next three frames predict where this bird’s suitable climate may shift in the future—one frame each for 2020, 2050, and 2080.

You can play or pause the animation with the orange button in the lower left, or select an individual frame to study by clicking on its year.

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season. More on reading these maps.
Winter
Summer

Winter Range
Summer Range
Both Seasons
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