Gavia arctica   (Linnaeus,  1758) (Bird)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Chordata
Class: Aves
Order:Gaviiformes
Family:Gaviidae

Image copyrights: pbase

Description
Size: 65 cm.

Streamline body, legs short and set far back, toes fully webbed, skilled divers and swimmers, plumage dense, compact and rather harsh, wings of 11 primaries, the outermost minute, rectrices 18 or 20. Tarsi reticulate and laterally compressed. Sexes alike (winter), dimorphic (summer), breeding extralimital. Sexes alike, practically a tailless bird with pointed and straight bill.

Color: Adult breeding:- Throat black, upper parts chequered black-and-white, head and nape uniformly grey, and black-and-white streaking on down sides of neck. Adult non-breeding:- In winter, without black throat but with dark grey upperparts and white underparts. Compared with Red-throated Diver, appears black-and-white rather than grey-and-white. Wings sparingly spotted with white.

Voice: A deep, barking 'kwow' in flight.

Habits: Expert divers, generally remain submerged and capture prey under water. Breeding- It breeds on deep, productive, freshwater lakes1 or extensive pools with islets, peninsulas and other inaccessible nesting sites3. Non-breeding- Outside of the breeding season the species is most common on inshore waters along sheltered coasts1, occasionally also frequenting large inland freshwater bodies1, 2 such as natural lakes or barrages, lagoons and large rivers.

Breeding season:-Arctic loons occupying southern regions begin their breeding season in May, whereas the breeding season in northern regions is determined by the onset of spring. In the spring they migrate from their wintering grounds.

Breeding site- The nest is a heap of plant matter placed near the water's edge1 on islets or hummocks emerging from the water, sometimes also on clumps of grass on the shore. Upon nest completion the female will lay 1 to 3 eggs. The eggs are normally olive-brown with dark brown spots. Incubation takes 27 to 29 days followed by a vital growth period of 9 to 10 weeks.

Reproduction: Arctic loons are monogamous, meaning they live their whole lives with only one mate. The couple stays together during their winter migration and on their wintering grounds. New couples use a number of synchronous movements including bill-dipping, splash diving and rushing under water. Mating occurs on the water banks and often occurs right after the birds have arrived in the breeding area. This species exhibits strong site fidelity and often uses the same nesting site for every breeding season. Gavia arctica will continue to use this site for a short time following mating.

The male loon is responsible for building the nest. Both parents take part in the incubation, but the females display a higher percentage of parental care. Incubation takes about 27 to 29 days followed by a vital growth period of 9 to 10 weeks, where both parents aid in rearing the offspring. The semiprecocial young spend the first day in the nest, but are able to swim at 2 to 4 days old. Both parents participate in feeding the young constantly throughout the first few weeks. Parents individually feed offspring one at a time, offering only one piece of food at a time, consisting usually of crustaceans. Newly hatched young often ride on their parents' backs, likely to avoid predators and conserve energy.

Lifespan/Longevity: Arctic loons are thought to be relatively long-lived birds. However, there is little information available directly pertaining to their lifespan. The oldest recorded wild Arctic loon lived to be 28 years old.

Synonym (s)

Common Name (s)
• Black-throated Diver (English)
• Arctic Loon (English)
• Black-throated Loon (English)
• Blackthroated Diver (English)
Economic Importance and Threats
Threats:  Anthropogenic
(During the breeding season the species is threatened by the acidification of breeding waters, heavy metal pollution and water level fluctuations especially during the incubation period. It also suffers from lower reproductive success due to human disturbance (e.g. from tourists or wetland visitors) and is indirectly affected by breeding habitat alteration (e.g. afforestation). During the winter the species is highly vulnerable to coastal oil spills, especially in rich fishing grounds where large congregation may occur, and is commonly caught and drowned as bycatch in fishing nets. The species is also highly sensitive to disturbance from coastal wind farms (wind turbines). )
Threats:  Natural threats
(Susceptible to avian influenza so may be threatened by future outbreaks of the virus.)
Importance:  Commercial
(Economic Importance for Humans: Positive

Inuit, a member of the Eskimo peoples inhabiting northernmost North America from northern Alaska to eastern Canada, use Arctic loons' eggs for food. They sometimes hunt loons on the breeding ground for consumption as well.

Economic Importance for Humans: Negative

Arctic loons feed primarily on fish and may be considered competitors for fishermen.)
Importance:  Ecosystem balance
(Arctic loons serve as both prey and predator within their ecosystems. They provide food for local predators as well as control populations of fish, crustaceans and aquatic insects. They are also a host to several different body parasites, most of which are tapeworms and flukes.)
Importance:  Dangers
(Arctic loons feed primarily on fish and may be considered competitors for fishermen.)

Ecology
Habitat:  Coastal
Trophic Level:  Consumer
Prey:  Fish, crustaceans and aquatic insects
Predator:  Bald eagles, Herring gulls, raccoons, gulls, crows and foxes
IUCN Status:  Least Concern

Biogeography


• INDIA
• Punjab, Ambala District INDIA (Record: 19/2/1922)
• Haryana, Jagadhri, W. Yamuna Canal (Lat: 30.11) (Long: 77.28)

Literature Source(s)
  • Kumar, A; Sati, JP; Tak, PC and Alfred, JRB (2005) Handbook on Indian wetland birds and their conservation Zoological Survey of India, Dehra Dun 468 pp Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org
  • (2003) IUCN Red list of threatened species Available at - http://www.iucnredlist.org/
  • PBase Available at - http://www.pbase.com/
  • Myers, P; Espinosa, R; Parr, CS; Jones, T; Hammond, GS and Dewey, TA (2006) Animal diversity web Available at - http://animaldiversity.org.
  • Vernacular names of the Birds of the Indian Subcontinent Buceros, Envis newsletter: Avian Ecology & Inland Wetlands 62pp Available at - http://www.bnhsenvis.nic.in/pdf/BUCEROS%203%20(1).pdf
  • Ali S and Ripley SD (1968) Handbook of the birds of India and Pakistan Oxford university press 1 1-368pp Available at - NIO

Page last updated on:2012-09-17

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