of its similar nesting habits, and it was formally applied to that species by Pennant in 1768. It was later extended to include the similar and related Pacific puffins. Since it may be more closely related to the rhinoceros auklet than the other puffins, it is sometimes placed in the monotypic genus Lunda. The juveniles, due to their similarity to C. monocerata, were initially mistaken for a distinct species of a monotypic genus, and named Sagmatorrhina lathami ("Latham's saddle-billed auk", from sagmata "saddle" and rhina "nose"). Distribution and habitat Tufted puffins form dense breeding colonies during the summer reproductive season from Washington state and British Columbia, throughout southeastern Alaska and the Aleutian Islands, Kamchatka, the Kuril Islands and throughout the Sea of Okhotsk. While they share some habitat with horned puffins (F. corniculata), the range of the tufted puffin is generally more eastern. They have been known to nest in small numbers as far south as the northern Channel Islands, off the coast of southern California. However, the last confirmed sighting at the Channel Islands occurred in 1997. Tufted puffins typically select islands or cliffs that are relatively inaccessible to predators, close to productive waters, and high enough that they can take to the air successfully. Ideal habitat is steep but with a relatively soft soil substrate and grass for the creation of burrows. During the winter feeding season, they spend their time almost exclusively at sea, extending their range throughout the North Pacific and south to Japan and California. Behavior Breeding Breeding takes place on isolated islands: over 25,000 pairs have been recorded in a single colony off the coast of British Columbia. The nest is usually a simple burrow dug with the bill and feet, but sometimes a crevice between rocks is used instead. It is well-lined with vegetation and feathers. Courtship occurs through skypointing, strutting, and billing. A single egg is laid, usually in June, and incubated by both parents for about 45 days. Fledglings leave the nest at between 40 and 55 days. Tuffen puffins may be purely aquatic locomotive animals until they are three, living entirely as marine animals returning to shore only to breed on the nesting cliffs where they hatched. They tend to be well offshore when hatching. Diet Tufted puffins feed on a variety of fish and marine invertebrates, which they catch by diving from the surface. However, their diet varies greatly