Do Gyrfalcons Nest in the Same Place Again

Geographic Range

The gyrfalcon (Falco rusticolus) is an arctic dwelling species with a holarctic distribution. It is rarely found south of 60 degrees. The majority of the breeding range is establish due north of 60 degrees while in parts of Eastern Canada it can be found breeding to 55 degrees, mainly along sea coasts. Although gyrfalcons are non-migratory, they volition disperse from the breeding range during the winter season, very rarely reaching the northern limit of the Us (Poole 1987; Wheeler and Clark 1995; Cade 1982).

• nearctic
  • native
• palearctic
  • native

Habitat

The gyrfalcon is typically found in northern latitudes abroad from the boreal woods. Although some individuals have been recorded nesting in trees, the bulk of individuals of this species nest in the arctic tundra. Nesting habitat is ordinarily among alpine cliffs while the hunting and foraging areas are more diverse. Foraging areas may include coastal areas and beaches that are used heavily by waterfowl, stooping off cliffs at unsuspecting prey such as small birds below them, or on the open up tundra where tail chases on ptarmigan and larger mammals is common.

Habitat fragmentation is currently not a threat to this species, due mainly to the short growing season and climate of the area. Since cliff faces are not disturbed and the tundra is not highly altered nor farmed, habitat for this species seems to be stable.

Winter can force this species to move regionally to feed. While in more southern climates, they prefer agricultural fields which remind them of their northern convenance grounds, typically perching low to the ground on fence posts (Pletz, E. 2000 personal communication; Poole 1987).

• tundra

Physical Description

The world's largest falcon is polymorphic, being recognized in three colour phases: white, greyness, and dark. The dark stage is dark grey, well-nigh black, in some individuals and groups of this morph are establish in northern Canada. The white morph is generally found in Greenland, and is usually almost pure white with some markings unremarkably on the wings. The greyness morph is an intermediate and plant throughout the range, typically two tones of grey are found on the body, nearly easily beind seen on the flying feathers versus the residual of the wing. This species is sexually dimorphic and thus has a broad ranging weight. Males counterbalance 800-1300g, averaging 53cm full length and females weigh 1400-2100g, averaging 56cm total length. The shape of the gyrfalcon is characteristically the same as nearly falcons. This includes long pointed wings (different the rounded wings of buteos), long tail and a notched bill. It also however, differs from other falcons by large size, shorter wings that only extend 2/three downward the tail when perched (compared with other falcons where the wings extend all the style to the tail), and broader wings. Adults characteristically have xanthous ceres, middle-rings and legs while juveniles display these features in a blue color. Every bit in all falcons, the eyes appear blackness. This species may perhaps only be confused with the Northern Goshawk (Accipiter gentilis) which inhabits dense forests, or the Peregrine Falcon (Falco peregrinus) which is somewhat smaller with a dark slaty-blue-black "helmet" and a lighter underside(Wheeler and Clark 1995; Cade 1982).

• endothermic
• bilateral symmetry

• Range mass

  800 to 2100 m

  28.19 to 74.01 oz

Reproduction

Gyrfalcons nest in the remote northern portions of the earth. Until recently, trivial was known about nesting sites, incubation times, fledging dates, or reproductive behavior. Although much has been discovered recently, many other aspects of the reproductive wheel have however to be determined.

Males begin defending nesting territory in mid-winter, about the end of January, while females generally go far at nesting sites near the beginning of March. Pair bonding occurs for nearly six weeks and after the eggs are usually laid near the end of April.

Gyrfalcons do non construct their own stick nests in trees (although quondam common raven (Corvus corax) stick nests in trees are sometimes used), and usually notice suitable nesting sites on cliff faces where in that location is a shelf with an overhang. Nest sites are used yr after yr and accumulate casualty remain piles, while the rocks turn white from excessive guano.

The clutch can exist from ii-seven eggs, nonetheless,the average size is 4, which is typically incubated past the female with some help from the male. Incubation has recently been determined to be 35 days and all birds in the clutch hatch within a 24-36 hour period.

Due to cold climate, chicks are covered in heavy down and are left to thermoregulate themselves after only 10 days as the female leaves the nest to join the male in hunting duties for the growing family (Cade 1982).

• iteroparous
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous

Lifespan/Longevity

• Average lifespan
  Condition: wild

  162 months

  Bird Banding Laboratory

Behavior

The gyrfalcon is a alone species except during the breeding flavor when it will interact with its mate. During not-breeding times, this bird volition hunt, forage, and roost lonely. Information technology is mostly non-migratory but will motility short distances, particularly during winter to suitable areas where prey tin can be institute.

This falcon has no natural enemies due to its big size, however, information technology volition exist eaten past a variety of animals if given the chance. Due to its large and capability of flying, many predators can't concentrate on hunting this species exclusively, and most mortalities occur to immature inexperienced birds or ones that become injured. Some animals of the north that may feed upon Gyrfalcons include Arctic fox (Alopex lagopus), red play a trick on (Vulpes velox), grizzly bear (Ursus arctos), wolverine (Gulo gulo), and great horned owls (Bubo virginianus) (Poole 1987; Cade 1982).

• flies
• motile

Advice and Perception

• visual
• tactile
• audio-visual
• chemical

Food Habits

Different eagles which use their big size to rob meals, and peregrine falcons which use gravity to proceeds tremendous speed, the gyrfalcon uses raw ability to capture prey, normally in a tail hunt. Usually low coursing flights are used in open habitat (no trees for concealment) where gyrfalcons will strike prey both in the air or on the basis . The majority of prey (by biomass) that consitutes the diet consists of ptarmigan (Lagopus sp.), Chill ground squirrel (Spermophilus parryii) and Arctic hares (Lepus arcticus). Other prey includes other small mammals (mice and voles) every bit well as other birds (ducks, sparrows, buntings)

While hunting, this falcon uses peachy eyesight to spot potential prey, as almost all animals in the north are cryptically colored to avoid detection. When potential prey is spotted a chase unremarkably occurs where more than likely the prey will be knocked to the ground in a powerful accident from the talons and so pounced upon. Gyrfalcons are powerful enough to accept sustained flight while hunting and occasionally wear their prey out until capture is easy. During nesting, the gyrfalcon will also cache meals with large prey such equally Chill hares between feedings. Rock doves (Columba livia), or pigeons every bit they are normally known, although non native are preyed upon heavily in major centers past gyrfalcons during winter months (Lange and Dekker 1999; Stelfox and Fisher 1998; Cade 1982; Poole 1987).

Economical Importance for Humans: Positive

Falconry is one of the oldest sports dating back some 4000 years, the majority proficient in the middle east. The white stage of the gyrfalcon, historically was hunted only by royality, and even today is still considered the "bird of kings". In North America, collecting wild raptors is illegal, only they are captured for trade in portions of their range in the Old World. McLean (1984) reports the demand to be high from the middle east, while Trefry (2000, personal communication) suggests few gyrfalcons are bred in captivity. Unfortunately, many are captured illegally and sold on the blackness market.

Another economical aspect of this bird is its rarity to birdwatchers, many of whom are willing to travel to picket, study and photo this bird. These travellers must exist transported, fed, and sheltered, all of which have economic science spinoffs to the communities where these birds are plant.

To a small extent, these birds are hunted for food and feathers used for clothing or formalism purposes by native Inuit. This number is small and they are not hunted exclusively, only opprotunistically and are spiritually significant to the native people of the northward (Holt 1999, personal communication; McLean 1984; Trefry 2000, personal advice) (McLean, 1984)

Economic Importance for Humans: Negative

In that location are no reported negative impacts by the gyrfalcon on humans.

Conservation Status

In Canada, the gyrfalcon is not recorded equally endangered, threatened, or species of special concern. Population estimates are currently thought to be under 50 000 birds total, with many of these being sub-adults and not sexually mature. Also, population levels have stayed fairly constant with little flucuation over the long term. This is possibly due to the fact that habitat loss is not a major concern due to low human interaction in the north, the fact that there is no hunting flavor on these birds, and pesticides levels take been lower in these non-migrators.

In the United States this species has been given no special status equally information technology is only a vagrant visitor and does non breed in the mainland U.s.a.. This species does however, nest in Alaska where populations seem to be stable.

Poaching, mainly in the form of capturing and selling birds to falconers is notwithstanding a major concern. Due to tight restrictions on exporting in Canada, this does not occur very often or at least is non detected very frequently. Besides, due to its habitat and its remoteness, these birds are not regularly captured.

Raptor monitoring, through surveys and banding is becoming more than prevalent, however, do to their remoteness, not all areas are covered in every bit neat of detail. This is due to the fact that birds of prey are skillful indicators to overall ecosystem health. Past monitoring these big birds, nosotros can determine if the ecosystem is on a downwardly slide early and try to restore information technology.(Poole and Bromley 1985;)

• IUCN Cerise List

  Least Concern
  More data

• IUCN Red List

  To the lowest degree Concern
  More information

• U.s.a. Migratory Bird Human activity

  Protected

• United states of america Federal List

  No special condition

• CITES

  Appendix I

• State of Michigan List

  No special status

To notice gyrfalcons in the wild, the best time is commonly the winter when they seasonally disperse from their breeding grounds. Open up areas, like to the arctic tundra, with food will commonly accept a visiting gyrfalcon in northern climates. Open water with overwintering waterfowl is especially good areas to see these birds. Large numbers of rock doves may too prove to be areas where gyrfalcons will hunt.

Unremarkably, patience is required to view these birds, as they are rare, even in their normal range. To view one in the wild is special, to see one hunt in the wild is boggling.

Contributors

Tyler Flockhart (writer), Academy of Alberta, Cindy Paszkowski (editor), University of Alberta.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern function of the New Earth. This includes Greenland, the Canadian Arctic islands, and all of the North American equally far due south as the highlands of key Mexico.

Palearctic

living in the northern part of the Former World. In otherwords, Europe and Asia and northern Africa.

audio-visual

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can exist divided in i plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambience temperature. Endothermy is a synapomorphy of the Mammalia, although information technology may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

iteroparous

offspring are produced in more than one grouping (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the fauna is naturally establish, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female person; development of offspring occurs outside the mother's trunk.

sexual

reproduction that includes combining the genetic contribution of 2 individuals, a male and a female

tactile

uses touch to communicate

tundra

A terrestrial biome with low, shrubby or mat-like vegetation establish at extremely high latitudes or elevations, near the limit of establish growth. Soils unremarkably bailiwick to permafrost. Plant diverseness is typically depression and the growing season is short.

visual

uses sight to communicate

References

Cade, T. 1982. The Falcons of the Globe.. Ithaca, New York: Comstock/Cornell University Press.

Lange, J., D. Dekker. 1999. The Downtown Falcon vs. Pigeon Show. The Edmonton Naturalist, V 27, no.i: 10-11.

McLean, B. 1984. Gyrfalcon nesting survey in a southern Baffin Isle, May-June 1984. Report prepared for the Baffin Regional Inuit Clan and the Baffin Regional Council.

Poole, Chiliad. 1987. Aspects of the environmental, food habits and foraging characteristics of Gyrfalcon in the key Candian Arctic. M.Sc. Thesis. Edmonton, Alberta: University of Alberta.

Poole, K., R. Bromley. 1985. Aspects of the environmental of the gyrfalcon in the key Canadian arctic, 1983 and 1984.. YellowKnife, NWT: Northwest Territories Renewable Resource.

Stelfox, H., C. Fisher. 1998. A Winter Birding Guide for the Edmonton Region. Edmonton, Alberta: Edmonton Natural History Club.

Wheeler, B., Due west. Clark. 1995. A photographic guide to North American Raptors. San Diego, California: Academic Press Inc..

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Source: https://animaldiversity.org/accounts/Falco_rusticolus/

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