Fratercula corniculata
horned puffin

Fratercula corniculata, horned puffins, is widespread in the Pacific and low Arctic. It breeds along the coast of British Columbia, on some islands and peninsulas around Alaska, and along the Bering Sea coast of Russia. It winters off shore, mainly in the North Pacific. The species is commonly found on Russian islands but can also be seen off the coast of Japan and British Columbia, rarely as far south as southern California. Horned puffins tend to stay in their breeding grounds during the winter as long as the grounds are not iced over.

In Alaska, 50% percent of all individuals live ninety kilometers from the mainland of the west coast, on the Semidi Islands. (Freethy, 1987; Gatson, et al., 1998; Harrison, 1983; Hatch, 1983a)

Horned puffins nest in bluffs of fractured rock or crevices in cliff faces near the shoreline. They may also create burrows in upland areas. In the Semidi Islands, they occur in the same habitat as parakeet auklets (Aethia psittacula). (Freethy, 1987; Gatson, et al., 1998; Hatch, 1983a)

Horned puffins forage off shore close to their breeding colonies, spending most of the year in coastal waters. They show no preference with respect to water temperature or salinity. They winter off-shore, preferring open water areas with large populations of the pelagic fish on which they feed. (Gatson, et al., 1998; Hoyo, et al., 1996)

The most common time for mating is either morning or evening. Birds indicate readiness by head flicking, which may be done either on land or in water. During this display, the bill may be open or closed. Members of a pair may mutually bow or put their bills side by side. Horned puffins form monogamous pairs.

Males may perform a swim display in which they raise themselves from the water and extend their necks upwards. Then they flick their heads, and at this time mounting is often observed. Mating takes place mostly in water with some rare cases on land. ("Alaska Seabird Information Series", 2006; Gatson, et al., 1998)

The general reproductive behaviors of horned puffins are not as well known as those of most auks. Birds arrive in the breeding colonies between April and May. Colonies are usually small. The nesting sites are on steep slopes or cliffs, and nests are usually separated by a distance of 1.5 meters. The nest itself may be in a burrow, in a rock crevice (usually), or under a boulder. It is lined with feathers, grass, or debris collected by both sexes.

A mating pair produces one egg, which is oval in shape. If the egg is lost it is replaced in 10 to 21 days. The egg itself is gray with purple dots, a type of spotting that suggests an ancestral habit of laying eggs out in the open. Horned puffin eggs quickly become covered in guano and other debris. They incubate for around 41 days, and both males and females participate in caring for and incubating eggs.

After the egg is hatched, parental care continues for 6 days. Feeding of a chick is done during the day by both parents. The chick becomes able to manage its own body temperature between 5 and 6 days after hatching. After this and for the next 35 days, the chick is left alone in the nest while both parents bring it food. There is no evidence of post-fledging care and the chicks depart at night by themselves. Horned puffins reach reproductive maturity between 3 and 5 years of age.

Not much is known about the molting process besides that it takes place in autumn to winter, and bill ornaments are dropped at the end of caring for the chick.

Like some other marine birds, females have sperm storage glands. It is not known if they are functional. (Freethy, 1987; Gatson, et al., 1998; Hatch, 1983b)

Female horned puffins lay a single egg in the spring, which is incubated by both parents for 41 days. After the egg hatches, the parents tend the chick closely for the next week. The chick is born altricial, but is able to thermoregulate a little over a week after hatching. After that, the chick is left alone in the nest for the next 37 to 46 days while being attended by the parents only for feeding. Pairs defend their nests and males defend their mates. Males show a threat display and fight if provoked. (Gatson, et al., 1998; Hatch, 2002)

The life span of Fratercula corniculata is not well studied. Some estimates are that it can survive 20 years or more. (Gatson, et al., 1998)

In captivity the horned puffin does not do well, especially when taken as a chick. A chick's diet must be supplemented with vitamins or it dies quickly due to malnourishment and bacterial infections. (Tocidlowski, et al., 1997)

These birds are usually not vocal but become so when they are threatened. They are diurnal, and peak time for them to be on land is between 8am and 12pm. They do not interact with other auks in their colonies.

Horned puffins are nomadic and move from breeding grounds when they are too iced over. (Freethy, 1987; Hatch, 1983a)

The densities of horned puffin colonies are determined by nest site availability. The higher the breeding site above the water, the less favorable it is considered to be.

Fratercula corniculata winters close to the breeding grounds and individuals are interspersed at low densities. Over-wintering locations and patterns, however, are poorly known.

The flight of the horned puffin is characterized by a quick take-off. After taking flight these birds beat their wings in a rapid yet shallow pattern. They fly at least thirty meters above the sea. (Freethy, 1987; Hoyo, et al., 1996)

The typical nesting range is unknown but individuals need almost two meters between nests. The nesting pair defends its site. (Gatson, et al., 1998; Hoyo, et al., 1996)

Monitoring these birds is difficult and little is known about their communication. It is clear that horned puffins are not very vocal birds. When it does produce noise it is low pitched and comparative to a groan or growl. In aggressive defense they produce a sound described as "A-gaa-kah-kha-kha" and during head flicking there is a repetative "op-op-op-op." Visual displays are important in pair formation, courtship, and nest defense. Like all birds, horned puffins perceive their environments through visual, auditory, tactile and chemical stimuli. (Golubova and Nazarkin, 2009; Hatch, 1983a)

The main staple of horned puffins is fish such as juvenile herrings (genus Clupea), capelin (genus Mallotus), and sand lances (genus Ammodytes). Puffins also sometimes prey upon salmon (genus Oncorhynchus) and cod (genus Gadus). They capture fish by surface diving. During the summer the diet varies. It may include fish, squid (class Cephalopoda), and other invertebrates. Diets of forty-one individuals from Buldir Islands contained, in order of abundance, squid, then fish, then marine worms (Polychaeta). The diet of the horned puffin during winter is not well studied. Puffin chicks are fed mostly raw fish. ("Alaska Seabird Information Series", 2006; Gatson, et al., 1998; Golubova and Nazarkin, 2009)

Fratercula corniculata is preyed upon mainly by introduced species. Significant predators include Arctic fox, red fox, and Norwegian rats. Nevertheless, predation does not substantially affect horned puffin populations because of their hard-to-reach nesting sites. ("Alaska Seabird Information Series", 2006)

Horned puffins prey on fish, squid, and marine worms, but the overall impact of this predation on prey populations is unknown. They have little impact on other auks because of the isolated nesting grounds this species prefers. ("Alaska Seabird Information Series", 2006; Freethy, 1987; Gatson, et al., 1998)

Alaskan Natives used horned puffins as food and clothing. Parkas are made from the tough skin of this auk and the feathers provide the natives with further insulation. The eggs are still collected as food in the Bering Straight region with minimal effect on the populations. Fratercula corniculata also is the focus of tourism in some regions of Alaska. ("Alaska Seabird Information Series", 2006)

This species has no significant negative impact on humans. ("Alaska Seabird Information Series", 2006)

The estimated breeding population for horned puffins today is 1.2 million birds, with most breeding on islands off the coast of Alaska. The largest breeding populations are in the Semidi Islands with 350,000 breeders. (Gatson, et al., 1998)

Horned puffin breeding numbers appear to have dropped from 1977 to well into the mid 1990’s. Overwater counts have produced conflicting results, however. Some have have not shown a significant decline, while others estimates have suggested that sea-bird populations, including horned puffins, dropped by 50 percent from 1972 to 1993. One boat-based viewing survey suggested a 79 percent drop in horned puffin populations in Alaska from 1972 to 1998. Horned puffins have been found to carry toxic trace metals, including mercury and cadmium. These are contained in the fish that that puffins eat and have been found in the livers of horned puffins. Also, upon autopsy some horned puffin individuals have been found with PCBs and organochlorine pesticides. ("Alaska Seabird Information Series", 2006; Agler, et al., 1999; Elliott, 2004a; Elliott, 2004b; Hatch, 1983a)

Another major source of mortality in this species is bycatch in fishing gillnets. Losses due to bycatch were most significant in the 1950's through the 1990's, when tens of thousands of puffins were killed by salmon and squid fisheries. Since that time the bycatch has been more carefully monitored and has not led to further significant population decline. ("Alaska Seabird Information Series", 2006; Schreiber and Burger, 2002)

The fact that horned puffins are crevice nesting birds has made studying them and monitoring their populations quite difficult. The nesting sites are hard to locate and it may be impractical to count all individuals. Instead, counting of individuals must be done by monitoring bird counts at peak season or by counting birds that have been rafted offshore.

Weather affects monitoring as well. Wind speed, but not not sky conditions or precipitation, has a statistically significant affect on the counts. Overall, there is a weak drop in counts of puffins when weather is poor.

Extrapolating trends can be difficult because counting individuals and estimating breeding pairs does not yield an accurate reflection of colony numbers the following year. Some researchers have devised a technique that could help with this problem called an over-water count. This involves counting the puffins as they are flying to or from the nesting area. It allows one to count the birds in a standard setting, facilitating comparisons, but the accuracy of these counts and their ability to detect change has been questioned. ("Alaska Seabird Information Series", 2006; Freethy, 1987; Gatson, et al., 1998; Hatch, 1983a)