Dovekies and penguins are an excellent example of convergent evolution. Both dovekies and penguins have developed similar morphological and physiological characteristics in order to adapt to icy conditions at the northern and southern poles of the earth. These equivalent niches caused both dovekies and penguins to evolve thick layers of blubber in the body, small, stiff wings, webbed feet, overlapping down feathers, and strong toe-nails.
Dovekies mainly use vocalizations to communicate. The ‘trilling call’ is the main type of vocalization and is used for recognition during flight, on land, and on water. The ‘trilling call' is used to identify mates. Other vocalizations include an alarm call, indicating predators are near, a 'clucking call', for close contact communication, and a 'billing call' that is often used after eggs have been laid. Chicks use a loud begging call for food, and a shrill peeping sound when separated from parents.
Another form of communication is body language. Dovekies use a 'head-vertical' posture when they have claimed a breeding territory. They use a 'head-down' landing posture, and rolling walk, in order to indicate passivity while intruding nesting territory claimed by other dovekies.
Additionally, dovekies have exceptional underwater vision. This is useful for capturing plankton at depths that offer little ambient light. It is speculated that they use bioluminescence to locate prey.
Communication Channels: visual ; tactile ; acoustic
Other Communication Modes: duets
Perception Channels: visual ; tactile ; acoustic ; chemical
Dovekie populations are relatively stable and sufficiently large. However, oil spills and deliberate introduction of mammalian predators such as arctic foxes for fur-farming have had a considerable impact on dovekie populations in the past.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Dovekies have no significant negative impact on humans. They are not pests, and do not compete with the fishing industry. They live and nest far from human populations.
Dovekies have nutritious eggs that have long served as a food source for local indigenous people. Their skins, bones, and beaks have been used for making garments and ornaments. Additionally, large populations of dovekies allow arctic fox populations to thrive, which in turn benefits local indigenous people who use fox furs for trading purposes.
Positive Impacts: food ; body parts are source of valuable material
Dovekies play an important role as predators, affecting and perhaps even regulating zooplankton populations, and as prey, supporting mammalian predator populations in the Arctic Circle. Due to their large abundance and wide distribution, dovekies may be considered a keystone species in the Arctic Circle. In large nesting colonies, dovekie guano creates excess nitrogen, killing macrophytic plants and leaving only nitrogen-tolerant vegetation, such as lichens.
Ecosystem Impact: keystone species
Dovekies are carnivores. They eat crustaceans, annelids, and mollusks, and small fish, but mainly depend on planktonic crustaceans for survival. Euphasiids, amphipods, Arctic cod, Calanus finmarchius, Gammarus species, Mysis species, Atylus carinatus, Argonauta arctia, and Parathemisto libella are all eaten by dovekies.
Dovekies have an enhanced capacity to store oxygen in their tissues, so they can use anaerobic respiration to perform long dives for food. They often dive 40 m below surface in pursuit of prey. They use their wings to move through the water by flapping them back and forth. This flying motion is unusual, but dovekies have small, stiff wings that are adapted for this type of underwater movement. They usually feed in the daytime when plankton is more visible.
Animal Foods: fish; terrestrial non-insect arthropods; mollusks; aquatic crustaceans; zooplankton
Primary Diet: carnivore (Eats non-insect arthropods); planktivore
Alle alle, commonly named little auks or dovekies, are native to the Nearctic and Palearctic regions. During non-breeding, winter months they are distributed from the southern limit of the pack ice south to the Gulf Stream, Virginia Capes, and Faeroe Islands. They breed north of the Arctic Circle from North Greenland, Franz Josef Land, and Novaya Zemlya south to North Iceland. With rising average global temperature, the pack ice has been retreating, so each year dovekies follow the south edge of the pack ice further north. Individuals are rarely seen much further south, as far as Cuba and the Canary Islands.
Biogeographic Regions: nearctic (Native ); palearctic (Native ); oceanic islands (Native ); arctic ocean (Native ); atlantic ocean (Native )
Other Geographic Terms: holarctic
Dovekies are adapted for marine habitats and live and feed offshore near upwelling zones or at oceanic fronts. They only come ashore to breed, when they seek out rocky scree slopes, eroded cliff faces, talus nooks, or porous lava flows from recent volcanic actions. They spend most of the winter in the northwest Atlantic foraging where plankton is abundant.
Range elevation: 400 (high) m.
Average depth: 40 m.
Habitat Regions: temperate ; polar ; terrestrial ; saltwater or marine
Terrestrial Biomes: tundra ; icecap
Aquatic Biomes: pelagic ; coastal
Although little information is available, it appears that dovekies normally live from 10 to 25 years of age. Natural lifespan of dovekies is often shortened by predation.
Typical lifespan
Status: wild: 10 to 25 years.
Average lifespan
Status: wild: 16 years.
Dovekies are one of the smallest seabird species. They are 19 to 23 cm in length, with an average wingspan of 40 cm. They weigh 140 to 152 g, and have a short, round body with a small sparrow-like bill. They are rotund birds, with rounded cheeks and a compact body. Two subspecies have been identified, and differ on the basis of size. The majority of dovekies belong to the smaller subspecies A. a. alle. The larger A. a. polaris is known only from Franz Josef Land and Severnaya Zemlya.
In the winter, dovekies have a distinct black and white coloration. They have a black bill and black neck, glossy black dorsal parts and tail, a white breast and belly, and black tarsi (toes and webs). They have dark brownish-black coloration under the wing. In the summer, the black coloration in the breast fades to a 'sooty' brown color, and the cheeks, chin, and throat also develop some brown feathers. Additionally, in the summer they develop a white patch behind the eye and the secondary feathers have white tips. For the most part, dovekies exhibit sexual monomorphism, except that the male has a larger bill, and the summer and winter plumage is different.
Dovekies are born with thick, dark plumage. The color varies from nearly black to a pale gray. Chicks lack the white eye patch behind the eye, and have a lighter coloration on their throat. Their back plumage is dull, not yet glossy like the adults, and their bill is browner. Chicks eventually undergo a complete molt and gain flight feathers that replace the body feathers.
Dovekies have small wings adapted for water, thick bodies, and large feet towards the front of the body. They have dense waterproof plumage and strong bones to resist water pressure. Dovekies bodies are highly adapted for cold temperatures. Their bodies have a small surface area, with thick layers of fat that insulate main organs and prevent heat loss. They have thick plumage that insulates the body from the freezing temperatures of the water. Their basal metabolic rate ranges from 2.29 to 2.55 cm^3 oxygen/hr, with an average rate at 2.42 cm^3 oxygen/hr.
Range mass: 140.3 to 164.7 g.
Range length: 19 to 23 cm.
Average length: 20.5 cm.
Average wingspan: 40 cm.
Range basal metabolic rate: 2.29 to 2.55 cm3.O2/g/hr.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; sexes colored or patterned differently
Humans, wild cats, arctic foxes, raccoons, mink, glaucous gulls, rats, and presumably other rodents are predators of dovekies when they are nesting on land. Most of these predators prey on both young and adult dovekies, but the smaller species, such as rats, feed on eggs. Dovekies have a black glossy back and fly low to the surface of the water in order to disguise themselves from gulls. They nest on high altitude, rocky, sloping, terrestrial landscapes to avoid proximity to predators. They travel and nest in large groups and use vocal warnings when predators approach. They may have marine predators, but we do not have detailed information on this.
Known Predators:
Anti-predator Adaptations: cryptic
Dovekies are monogamous and breed seasonally. They form pair bonds at their breeding site, which last for several years. Pairs reunite at the same nesting site each year. Although monogamous, it has been found that females sometimes copulate with other males when their mate is away from the colony, and most sources indicate that more research is needed in this area.
During breeding season, large colonies of dovekies, ranging from 1000 to several million, will gather at a nesting site. The site is usually a coastal cliff side, nunatak, or mountainside within 30 km from the coast. Nests are normally distributed in small groups of ten or more. Individual nesting sites are claimed by the male and are 0.5 to 1.0 m in diameter. The nest is comprised of a layer of pebbles that lead from the entrance to the depression where the egg is laid. At the entrance, a large rock normally marks the territory and is used for taking off. The nest is defended by the male, and fighting over nest sites will occur between males. This mainly involves relatively harmless grappling and interlocking of bills. After successfully claiming a nest site, a male will use a ‘head-vertical posture’ to indicate his claim. Also, there have been observations of males flying over a site and dropping a pebble, possibly indicating their intention to claim a site.
Males will approach females and use postures and vocalizations to attract the attention of females. Females then inspect males, and if a male is found suitable, the pair will often engage in a ‘head bowing’ ceremony that involves facing each other and mutually bowing their heads for approximately one minute. Then, ‘clucking’, bill touching, and fluttering of wings occurs. Pairs may then engage in a slow, low to the ground ‘Butterfly’ flight, ritualized walks, or preening and unique displays of various postures. Shortly after, copulation will occur. There is not much information available regarding male protection of his female mate.
Mating System: monogamous
Dovekies return to breed as early as February, and as late as May. Dovekies will lay and incubate one egg per breeding season. This could be due to the short amount of time allowed for breeding, which is influenced by the quick closing of the pack ice. Eggs are very large, averaging from 4 to 5 cm in length, and weighing an average of 30 g. Incubation periods usually last 29 days, and eggs begin to hatch four days after the first pipping crack appears. Chicks are born semi-precocial and brooded 2 to 4 days until becoming homeothermic. After this, chicks are left alone except during feeding, and start to exercise at the mouth of the nest cavity when aged 15 days. The chick reaches peak weight at age 21 days, and at 23 days most chicks exhibit highest fat proportions. They fledge when aged 27 to 28 days. Fledging is often synchronized and matured young depart from the colony either singly, with parents, or in small groups. Dovekies reach sexual maturity when aged 3 years, and breed until aged 8 years.
Breeding interval: Dovekies lay one brood per year.
Breeding season: Breeding mainly occurs from March to June.
Average eggs per season: 1.
Average time to hatching: 29 days.
Average fledging age: 27 days.
Average time to independence: 29 days.
Average age at sexual or reproductive maturity (female): 3 years.
Range age at sexual or reproductive maturity (male): 3 to 8 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
About a month before breeding season, dovekies will feed heavily, especially females, in order to prepare their bodies for the energy expenditures involved with breeding. This is especially important for females, because eggs are very large, and require a major allocation of resources. Normally the male will prepare the nest site, and after copulation and egg-laying, both male and female parents provide care and protection at nest site. Protection merely involves covering the egg with a wing, and being on the look out for predators while incubating the egg. Parents take shifts incubating the egg, females mostly tend to the egg during the day, and males at night.
After hatching, both parents take care of the chick until it develops a layer of down and becomes homeothermic. They both take trips to retrieve food for the young, mainly copepod crustaceans. This involves flying as far as 20 kilometers from the nesting site 4 to 14 times daily, catching food, and delivering it back to the nest in elastic gular pouches. It was found that males retrieve the food more often than females. As the chick begins to mature, fledging is learned from both parents. Therefore, parental care during all stages of reproduction is divided equally between male and female parents. Chicks are abandoned at sea shortly after fledging occurs, but parents will sometimes still associate with their young as they roam the open ocean in the winter months.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female); post-independence association with parents
