Rhinoceros Auklet

The rhinoceros auklet (Cerorhinca monocerata), is a seabird and a very close relative of the birds that we know as puffins. She is the only living member of the genus Cerorhinca. Due of its close connexion with the puffins the common name rhinoceros puffin has been proposed for the species. It occupies large parts of the North Pacific, feeding on small fish and breeding in colonies. Its name derives from a horn-like extension of the beak (the rhamphotheca for this extension is anatomical term). This horn is only found in breeding adults, and is shed on the bill of puffins each year like the delicate sheath. The rhinoceros auklet (also known as the rhino auklet, horn-billed puffin, or unicorn puffin) is a medium-sized auk with a broad, sturdy, orange / brown bill (with the ' tail ' sticking out of it). The plumage is black on top and light below; both male and female breeding adults have white feathers behind their eyes and behind their ears. Males are significantly heavier than females (about 10 per cent weight). The rhinoceros auklet is a North Pacific auk that occurs from California to the Alaskan Aleutian Islands in North America; and Hokkaidō and Honshū, Japan, as well as the Korean Peninsula and Sakhalin Islands in Asia.

This winters in coastal waters and inshore waters and shows some migration. The rhinoceros auklet nests in burrows which sink into the ground, or in natural caves and cavities between 1 and 5 m deep. It picks nesting sites on mild inclines to support take-off, as it is a poor flier. Both parents spend 45 days incubating one single egg. The semi-precocial chick is then fed a bill full of fish (in the manner of puffins) for 50 days a night; this nocturnal behaviour is believed to be a response to the predation and kleptoparasitism of gulls. Rhinoceros Auklets are monogamous, and while migration through common environments during the non-breeding season, pair-mates migrate separately.

They do, however, synchronise their foraging actions until they return to the colony during the pre-laying period. Rhinoceros auklets feed on fish at sea, and sometimes take some krill and squid with them. They eat in the Midwater inshore during the breeding season. They have dived as deep as 57 m (187 ft) to catch their prey for as long as 148 seconds. The genus Cerorhinca formed in the North Pacific, possibly in Mid-late Miocene. As if only one species exists today, it used to be much more diverse in terms of numbers of species as well as distribution. Fossils were south up to Baja California. Smith et al. (2007) reported the Atlantic Ocean's first clade data, and suggested that the biogeographic past of Cerorhinca is more complex than previously thought.

Both male and female Auklets Rhinoceros bear a "bell" at the end of the bill. There is no comprehension of the role of the attribute. The Auklet Rhinoceros takes food to their nest site often at night. This behaviour may be an adaptation that stops gulls and other animals from stealing their food. The oldest known Rhinoceros Auklet was at least 28 years, 3 months old. It was found in 2010 in Washington, and was banded in 1984 in British Columbia. The Auklet Rhinoceros, noted for the triangular white plate at the base of its spine, is a marine species and an open sea in the north Pacific. It is the only member of its family and it is closely associated with puffins. A chunky dark seabird occasionally common off the north Pacific coast, close to the puffins. Often unaware, but boats really low on the water will hit this. When moved it instinctively sinks and swims underwater. Although taking off tends to be sluggish and laborious, it is a fast flier and can fly long distances to feeding areas everyday. The "hair" on the bill, which is responsible for the name of the bird, grows each year in early spring and will be shed late summer.