- 11–11.4 in
- 23.2–24.4 in
- 12.3–21.9 oz
- Alque rinoceros (French)
- Alcuela rinoceronte (Spanish)
- Both male and female Rhinoceros Auklets bear a "horn" on the base of the bill. The function of this feature 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.
Mostly pelagic; nests on islands in ground burrows.
- Condition at Hatching
- Covered in down, can walk, but stay in nest.
Dives underwater to capture prey, using its wings to swim.
Vulnerable to the effects of oil spills. Raccoons and other introduced mammals have caused catastrophic population losses and possibly total elimination of some colonies.
- Gaston, A. J., and S. B. C. Dechesne. 1996. Rhinoceros Auklet (Cerorhinca monocerata). In The Birds of North America, No. 212 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, sand The American Ornithologists Union, Washington, D.C.