Cerorhinca monocerata
The Rhinoceros Auklet (Cerorhinca monocerata) is a robust, medium-sized seabird belonging to the Alcid family, instantly recognizable by the unique horn-like projection above its bill during the breeding season. Measuring approximately 35-40 cm (14-16 inches) in length with a wingspan of 56-64 cm (22-25 inches) and weighing 500-800 grams (1.1-1.8 lbs), this species exhibits a sleek, dark slate-gray to black plumage on its dorsal side, contrasting sharply with a clean white belly. Its most dis...
Primarily a coastal marine species, Rhinoceros Auklets inhabit temperate and subarctic North Pacific waters, favoring offshore islands, rocky islets, and coastal headlands with suitable soil for burrowing. They forage in productive pelagic zones, often near upwellings or continental shelves, and ...
The diet consists predominantly of small schooling fish such as juvenile herring, anchovies, smelt, and sandlance, supplemented with crustaceans and squid. They are expert pursuit divers, actively hunting prey underwater.
Rhinoceros Auklets are largely pelagic, spending most of their lives at sea, but become strikingly nocturnal at their breeding colonies to minimize predation from gulls and raptors. Foraging involves impressive pursuit diving, where they use their powerful wings for propulsion underwater to catch...
The Rhinoceros Auklet's extensive breeding range spans the temperate and subarctic North Pacific. Key breeding colonies stretch from the Aleutian Islands and Gulf of Alaska south along the coast of British Columbia, Washington, Oregon, and down to central California (e.g., Farallon Islands). Acro...
Least Concern
- The Rhinoceros Auklet is named for the distinctive "horn" or cornified plate that grows on its upper bill during the breeding season and is shed afterward. - They are one of the most nocturnal seabirds at their breeding colonies, arriving and departing under the cover of darkness to avoid preda...