Aethia cristatella

Geographic Range

Crested auklets are native to the Nearctic and Palearctic. They are common on remote islands and coastal areas in the Bering Sea and North Pacific (Jones 1993). They inhabit coastlines outside the Americas on the Chukotski peninsula in Eastern Siberia, Kurile Island, and other islands in the Okhotsk Sea. This species can sometimes be found wintering as far south Northern Japan (Jones 1993).

• Biogeographic Regions
• nearctic nearctic
  • native native
• palearctic palearctic
  • native native

Habitat

The preferred habitat of crested auklets is offshore and along the coasts of remote islands in the Bering Sea. They are one of the most abundant planktivorous sea birds found in the North Pacific and they nest in breeding colonies along with other species of auklets (Piatt et al. 1990). Rock crevices along talus slopes, boulder fields, or lava flows are critical for nesting. They situate their breeding colonies along these rocky cliffs so that they are facing the sea. Crested auklets are deep ocean foragers and often find their food far away from their nesting sites. During the winter season they flock in the nearby ice-free waters of the Gulf of Alaska and northern Japan (Hoyo et al. 1996). Little information exists on spring/fall migration among this species and their winter range.

• Habitat Regions
• polar polar
• terrestrial terrestrial
• saltwater or marine saltwater or marine

• Terrestrial Biomes
• tundra tundra

• Aquatic Biomes
• pelagic pelagic
• coastal coastal

Physical Description

Crested auklets are relatively small birds. Males and the females are similar in appearance. They differ in appearance from other auklet species that they nest with because all of their body plumage is dark. Their upper bodies are dark-grey while their lower bodies are usually brownish-grey. They have decorative, forward-coiled facial feathers and crests that distinguish them from other common birds in their range. Both sexes have ornamental feathers and facial crests, and these features vary in size with age and mass. Male birds typically have longer decorative crests than females. Adults molt their feathers once a year in order to grow new ones. Their facial decorations will be shed throughout March and April. These facial decorations endure a great amount of wear and tear throughout the breeding season so by fall they appear rather worn. The only difference between sexes is that longer feathers are found on the napes and necks of the males. Crested auklets have a very distinct citrus-like odor in their plumage which is important for them in both social and sexual behaviors (Jones et al. 2004).

Crested auklets have prominent white irises and a white stripe of feathers on each side of their head running from behind their eyes back to their ear-coverts. Their legs are grey and they have webbed feet with coal-black claws. Their bills are bright reddish-orange with a yellow tip. During the breeding season, the bill shape of this species differs between the sexes in that the female’s bill is less curved than the male’s bill, and it is slightly smaller in size. The noticeable curvature in the male’s bill during breeding seasons is thought to help them in their agonistic encounters. On the bills are brightly colored “horny” plates called the nasal plate, subnasal plate, rectal plate, and the maxillar plate. They will lose these plates at the end of the breeding seasons and after incubation periods. During winter, their bills become dull in color and slightly smaller in appearance due to loss of their facial ornamentation and facial plates. This makes identifying sexes more difficult at this time of year.

Crested auklets are covered in down at hatching. Some hatchlings have light grey abdomens and others have black abdomens, but nearly all of them have pale-grey patches on their bottom sides. Shortly after birth, at about 5 days, they begin a pre-juvenile molt. This molt lasts until they are around a month old. Juveniles are similar in appearance to adults except that their crests may not yet be visible. Their bodies are dark grey to black and the white stripe behind their eyes begins to develop and becomes slightly visible. Their irises at this stage of development are dark grey, their bills are black, and they are without their horny plates.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike
• male larger
• ornamentation ornamentation

Reproduction

Crested auklets are monogamous, with high site and mate fidelity throughout their breeding lives (Hoyo 1996). They compete with others for high quality mates and the best nesting sites. The more dominant crested auklets typically have longer crest lengths than other auklets in the colony. Longer crest lengths are preferred when these birds are selecting a mating partner. During the breeding season, pair bonds are formed following elaborate courtship behaviors including stereotypical postural displays that increase in intensity as the courtship between a pair progresses (Jones 1993). Many pair-bonds that form join to breed again in future breeding seasons.

After the first breeders arrive, non-breeders and juveniles arrive 3 to 4 weeks later. Some crested auklets participate in extra-pair copulations later in the breeding season as a way to assess the reproductive success of possible future partners. Males have been observed attempting extra pair copulations at their staging areas through aggressively disrupting pairs in the process of courting (Jones 1993). They rush in and attempt to disrupt females that are about to mate with other males. Birds that are not yet adults, and that are not yet breeding will make finding a suitable nest site their first priority. Adult auklets that are ready to breed and form a pair-bond display their courtship readiness by using the ocean as their staging area. This “staging area” is an area on the ocean that the male’s birds use to perform their courtship displays. This performance helps them attract a mate that they can form a pair-bond with and hopefully breed with that year. Some individuals that are not breeding may engage in courtship activities with extra-pair auklets near the end of the breeding season when chicks are either incubating or during the chick-rearing stage. Once a breeding pair of crested auklets re-forms prior to laying an egg, the male will actively guard the female and follow her around.

The female initiates courtship as she approaches a male that is trumpeting and performing a display. Both birds perform stereotypical postural displays that further advance their courtship (Jones 1993). During these mating rituals the male’s pupil contracts and appears glassy. The female stares intensely into his eye and then begins to touch the male’s facial areas with her bill. As long as the male doesn’t reject her, she will continue to court the male. Courtship between this pair continues with mutual cackling vocalizations along with intense billing, nibbling of male’s bill by the female, and burying bills in the nape and neck feathers of each other (Jones 1993). Both birds will touch each other with their bills and exhibit “ruff-sniff” displays toward each other. The climax of courtship is reached when the two begin neck twisting and then copulation begins.

Copulation in this species only occurs at sea. Copulation on water presents several issues including the possibility of loss of sperm during transmission if the female’s cloaca comes in contact with ocean water. During copulation, the male will look out for “scrums” in which several auklets will rush in and attempt to join/break up the mating. The male will actively defend his mating partner by chasing others off by using bill stabs against them.

• Mating System
• monogamous monogamous

The breeding season for crested auklets begins around May and lasts through mid-June. Timing of snow melt plays an important role in when exactly they begin breeding (Jones 1993). They lay a clutch size of one egg per breeding season and both parents are responsible for care of the chick. Most pairs will return to the same nesting site year after year unless a divorce occurred. Hatching is synchronous, with about 80% of the eggs hatching within a span of 10 days (Jones 1993). On average chick rearing lasts for about a month, sometimes longer; and they grow at a rate of 11 to 13 grams per day. Young do not fledge until they are close in body mass to their adult size. Several days before fledging young leave the nest site for awhile to start stretching out their flight muscles, referred to as “helicoptering” behavior. Little research has been done on the age at which young reach sexual maturity and can begin breeding. A few studies suggest that they begin to breed around three years old.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Chicks are precocial at the time of hatching. Both crested auklet parents participate in caring for young. Both incubate the egg and spend the night in their nest together. It is not yet known if parents help young during hatching. For the first day young are brooded continuously and both parents continue to brood for the fist week after hatching. Males brood young more than females do. After hatching, at least one of the adults will spend the first ten nights with their chick until they are able to thermoregulate themselves. After this occurs the chick can be left by itself in the nest if necessary.

Adults must forage for food for themselves and their chicks. They carry food in a sublingual pouch and feed the chicks one to four times a day. Females take more responsibility for feeding chicks than do males. After foraging for food, parents stay with the chick for about 5 to 10 minutes in the nest and feed it at regular intervals. Nests are kept clean and young do not defecate in the nest.

Parents care for their young from 1 to 3 months depending on where their colony is located. Chicks begin fledging when close to their adult mass. A few days before fledging they begin leaving the nest and stretching their muscles for flight. When ready they depart from the colony by taking flight from a boulder in attempt to fly towards sea where the risk of predation is extremely high.

• Parental Investment
• precocial precocial
• pre-fertilization
  • provisioning
  • protecting
    • male
    • female
• pre-hatching/birth
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

Little is known about the lifespan of crested auklets in the wild or in captivity. The estimated lifespan of this species is about 7.7 years. The estimated annual survival of adults in the populations is 86% per data from studies at Buldir, Alaska. These researchers color-marked certain birds at Buldir, and then documented their lifespan.

Behavior

Crested auklets are found in colonies or groups throughout the year. They nest in a colony on land during the breeding season and then flock in ice-free waters during the fall and winter months. When the breeding season begins, adults begin arriving at colonies in late April to June and sub-adults arrive around three weeks later (Jones 1993).

Crested auklets are highly social and vocal birds. Nesting colonies include several other auklet species. They are found year-round in flocks both at sea and in their nesting colonies. Crested auklets are highly aggressive towards other Aethia species that they nest with, especially least auklets ( Aethia pusilla ) (Jones 1993). Because they are so aggressive, they are able to chase least and whiskered auklets ( Aethia pygmaea ) from desired nest-sites, and from display areas at sea where mating occurs. Puffins occupy the same habitats as crested auklets, but crested auklets intentionally avoid them. Numerous antagonistic interactions occur at colonies which indicate competition between birds over nest sites and mates. The bill of male auklets becomes more curved and sharp during the breeding season in order to aid as a weapon in antagonistic encounters with others. Fights between males involve pecking at their opponent's eyes, seizing the gape, nape, or crest of their opponent, and grappling with their bills locked together (Jones 1993). The winners of the most violent fights are usually the auklets with the longest crests. Aggression also occurs at staging areas where copulation occurs. Males defend their mates from other males attempting extra-pair copulations. Female crested auklets are not as aggressive as males.

Crested auklets stand upright and move quickly and lightly on land. They can climb steep rocks using their sharp claws and a technique called wing fluttering. A unique characteristic about this species is that they produce a pungent citrus-like odor from their feathers, used in social communication and courtship. They are powerful flyers with long wings specialized for fast, direct flight. They can reach speeds of up to 30 to 40 meters per second, which creates a loud sound, especially when several birds are leaving the colony at once (Jones 1993). Crested auklets fly in flocks of 10 to 100 birds between nest sites and marine foraging areas. These birds are also strong swimmers. Their preening can take place on land or at sea. When preening, they use their beaks to spread their citrus-smelling secretions from their uropygial gland through their feathers. Preening is also a way in which they can waterproof themselves. They use intricate bathing rituals at staging areas before mating.

• Key Behaviors
• flies
• diurnal diurnal
• motile motile
• migratory migratory
• territorial territorial
• social social
• colonial colonial
• dominance hierarchies dominance hierarchies

Home Range

There is no information on home range for this species.

Communication and Perception

Crested auklets use visual, chemical, tactile, and acoustic modes of communication. They are very vocal during the breeding season and in flocks at sea. Nearly all of their communication occurs during the daytime when these birds are most active. Six different forms of vocal communication among adult crested auklets have been observed. They include barking, trumpeting, cackling, hooting and whining. A bark is a form of vocalization used by both sexes. It sounds like the “yap” of a small dog (Jones 1993). These “barks” are often associated with locomotion, such as when crested auklets leave the colony. This is a type of signal that can function as a location signal or a contact call to other birds in the flock or colony. Crackling is a vocalization that is performed by auklet pairs in the process of courtship. Crackling sounds like a series of clucking noises. This form of vocalization serves an important function in pair bonding. Hooting occurs from within crevices and sounds like a series of rhythmic soft bark-like sounds (Jones 1993). Whining is a form of softer communication in that is performed by solitary auklets that are not yet mating. Males emit a type of vocalization referred to as trumpeting. It is a form of sexual advertisement used in courtship displays. It consists of a series of honk-like sounds that increase in rhythm. These honking sounds are performed along with specific courting displays by that particular male. Trumpeting vocalizations are performed on top of large rocks at nesting sites or from staging areas at sea. Breeding males are frequently seen trumpeting in the pre-laying stage and then again during the chick-rearing stage (Jones 1993). Auklet chicks are also vocal. They are vocal throughout the day, especially while their parents are at and away from the nest site. Vocalizations consist of soft peeps and loud warble-whistles.

Few studies have been conducted on the exact purpose of plumage odor in crested auklets. During the breeding season these birds produce a pungent citrus-like odor, similar to tangerines. Plumage odor may have a social function in courtship because courtship involves a great deal of touching with the birds' bills in the strongly scented areas on their partners' necks (Jones 2004). The odor seems to play a more important role when these birds are in close contact with one another in colonies and at sea. Their behavior in these places indicates that the odor plays an important role in socializing and courtship because they closely interact and sniff each other. Behaviors such as rump-sniffing and neck-twisting are displayed during the more advanced stages of courtship among this species.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• duets duets
• pheromones pheromones

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Crested auklets eat crustaceans and other marine invertebrates including Thysanoessa euphausiids, mysids , hyperiids , gammarids , calanoid copepods , fish, and squid. They are deep ocean divers and forage underwater in social groups on colonial euphausiids on the ocean floor. Underwater, they pursue their prey in a rapid wing-propelled underwater flight (Jones 1993).

• Primary Diet
• carnivore carnivore
  • piscivore piscivore
  • eats non-insect arthropods
  • eats other marine invertebrates
• planktivore planktivore

• Animal Foods
• fish
• mollusks
• aquatic crustaceans
• other marine invertebrates
• zooplankton zooplankton

• Plant Foods
• phytoplankton phytoplankton

Predation

Crested auklets are preyed on by avian and mammalian predators and large, predatory fish. Avian predators attack crested auklets on land or at sea usually while they are flying. On land they wait near the nesting crevices and attack as they enter and leave. Mammalian predators enter nest crevices to take chicks and the eggs. Crested auklets are vigilant at nesting colonies and at sea in order to avoid predation. They usually wait for other auklets to take flight with them in order to have safety in numbers. When they are diving towards the sea they often weave back and forth in flight to avoid being an easy target for avian predators. When flying back to the colony they fly directly into their nest sites. Sometimes they circle above the colony, waiting for an opportune time to return. When predators are seen approaching, crested auklets make simultaneous panic flights in groups away from the colony as a way to alert the rest of the colony that a predator is nearby. Once caught by a predator, these birds fight back with aggressive bill-pecking, viciously scratching at their predators and beating their wings. Many of them are able to escape. Because most predation occurs during the day, some fledging of the chicks occurs at night when they are not as visible to predators (Jones 1993).

• Anti-predator Adaptations
• aposematic aposematic

Ecosystem Roles

The primary way in which this bird species affects its ecosytem is its role as prey for other animals.

Economic Importance for Humans: Positive

Crested auklets sometimes provide food for Eskimo and Aleut people. They are also valuable in research and education.

• Positive Impacts
• food food
• research and education

Economic Importance for Humans: Negative

There are no direct negative effects of crested auklets on humans.

Conservation Status

The status of the crested auklets on the IUCN Red List of threatened species is least concern. They are not on the United States Endangered Species Act list, but they are protected by the Migratory Bird Treaty Act.

Additional Links

Encyclopedia of Life

Contributors

Mandi Shifflett (author), James Madison University, Suzanne Baker (editor, instructor), James Madison University, Tanya Dewey (editor), Animal Diversity Web.

References

Ehrlich,, P., D. Dobkin, D. Wheye. 1988. The Birder's Handbook: A field guide to the natural history of North American Birds . New York, NY: Simon and Schuster Inc..

Fraser, G., I. Jones, J. Williams, F. Hunter, L. Scharf, V. Byrd. 1999. Breeding Biology of Crested Auklets at Buldir and Kasatochi Islands, Alaska. The Auk , 116/3: 690-701. Accessed May 05, 2009 at http://apps.isiknowledge.com/full_record.do?product=BIOSIS&search_mode=GeneralSearch&qid=4&SID=1DlOh3a9k5gMcBNK781&page=1&doc=4 .

Fraser, G., I. Jones, F. Hunter, L. Cowen. 2004. Mate Switching Patterns in Crested Auklets: The Role of Breeding Success and Ornamentation. Bird Behavior , 16/1-2: 7-12.

Hoyo, J., A. Elliot, J. Sargatal. 1996. Crested Auklet: Aethia cristatella. Pp. 718 in Handbook of the Birds of the World , Vol. 3, 1 Edition. Barcelona: lynx edicions.

Hunter, F., I. Jones. 1999. The frequency and function of aquatic courtship and copulation in least, crested, whiskered, and parakeet auklets. The Condor , 101: 518-528. Accessed May 05, 2009 at http://apps.isiknowledge.com/full_record.do?product=BIOSIS&search_mode=GeneralSearch&qid=1&SID=1DlOh3a9k5gMcBNK781&page=1&doc=7 .

Jones, I., J. Hagelin, H. Major, L. Rasmussen. 2004. An Experimental Field Study of the Function of Crested Auklet Feather Odor. The Condor , 106/1: 71-78. Accessed May 05, 2009 at http://www.jstor.org/stable/1370517 .

Jones, I., F. Hunter, G. Fraser. 2000. Patterns of Variation in Ornaments of Crested Auklets. Journal of Avian Biology , 31: 119-127. Accessed May 05, 2009 at http://apps.isiknowledge.com/full_record.do?product=BIOSIS&search_mode=GeneralSearch&qid=4&SID=1DlOh3a9k5gMcBNK781&page=1&doc=3 .

Jones, I., F. Hunter. 1999. Experimental evicence for mutual inter- and intrasexual selection favouring a crested auklet ornament. Animal Behavior , 51/1: 521-528. Accessed May 05, 2009 at http://www.idealibrary.com .

Jones, I., F. Hunter. 1993. Mutual Sexual Selection in a Monogamous Seabird. Nature , 362: 238-239. Accessed May 05, 2009 at http://apps.isiknowledge.com/full_record.do?product=BIOSIS&search_mode=GeneralSearch&qid=13&SID=1DlOh3a9k5gMcBNK781&page=2&doc=15 .

Jones, I. 1993. Crested Auklet. The Birds of North America , 0/70: 1-15.

Jones, I. 1993. Sexual Differences in Bill Shape and External Measurements of Crested Auklets. The Wilson Bulletin , 105/3: 525-529. Accessed May 05, 2009 at http://apps.isiknowledge.com/full_record.do?product=BIOSIS&search_mode=GeneralSearch&qid=9&SID=1DlOh3a9k5gMcBNK781&page=2&doc=16 .

Knudtson, E., G. Byrd. 1982. Breeding Biology of Crested, Lwast, and Whiskered Auklets on Buldir Island, Alaska. Condor , 84: 197-202. Accessed May 05, 2009 at http://apps.isiknowledge.com/full_record.do?product=BIOSIS&search_mode=GeneralSearch&qid=16&SID=1DlOh3a9k5gMcBNK781&page=1&doc=1 .

Piatt, J., B. Roberts, S. Hatch. 1990. Colony Attendance and Population Monitoring of Least and Crested Auklets on St. Lawrence Island, Alaska. The Condor , 92/1: 97-106. Accessed May 05, 2009 at http://apps.isiknowledge.com/full_record.do?product=BIOSIS&search_mode=GeneralSearch&qid=20&SID=1DlOh3a9k5gMcBNK781&page=1&doc=3 .

Piatt, J., B. Roberts, W. Lidster, J. Wells, S. Hatch. 1990. Effects of Human Disturbance on Breeding Least and Crested Auklets at St. Lawrence Island, Alaska. The Auk , 107/2: 342-350. Accessed May 05, 2009 at http://www.jstor.org/stable/4087618 .