Ecology and Biology of Gyrfalcons in Greenland.

Burnham, K. P.

doi:10.4080/gpcw.2011.0209

Cited by 10 publications

(11 citation statements)

References 33 publications

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“…), particularly during the early breeding season when prey are limited. In Kangerlussuaq, Gyrfalcon lay date from 1998 to 2006 ranged from 28 March to 9 May (mean = 17 April; Burnham & Burnham ), with Rock Ptarmigan Lagopus muta , Snow Bunting Plectrophenax nivalis and Arctic Hare Lepus arcticus being the primary prey available early in the breeding season (Salomonsen , Boertmann , K. Burnham unpubl. data).…”

Section: Discussionmentioning

confidence: 99%

“…Using similar sampling years, the timing of Gyrfalcon nest initiation was approximately 18 days earlier in Kangerlussuaq (mean lay date = 107.4, sd = 9.4, n = 70; this study) than in the Thule population c . 1200 km to the north (date = 125.0, sd = 7.0, n = 40; Burnham & Burnham ). The Kangerlussuaq Gyrfalcon population also exhibited a much wider range of dates for the nesting period duration.…”

Section: Discussionmentioning

confidence: 99%

“…The Kangerlussuaq Gyrfalcon population also exhibited a much wider range of dates for the nesting period duration. For example, fledging dates in Kangerlussuaq ( n = 66 nests) between 1998 and 2006 occurred over a 43‐day period, compared with 31 days among nests in Thule ( n = 40, 1994–2010; Burnham & Burnham ). In combination with the effects of low immigration and genetic drift (Johnson et al .…”

Section: Discussionmentioning

confidence: 99%

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Timing of breeding and offspring number covary with plumage colour among GyrfalconsFalco rusticolus

Johnson

Burnham

2012

Ibis

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Plumage colour variation exists among Gyrfalcons throughout their Arctic and sub-Arctic circumpolar distribution, ranging from white through silver and grey to almost black. Although different colour variants coexist within many populations, a few geographical regions, such as northern Greenland, possess a single variant, suggesting that local environments may influence plumage colour variation. In central-west Greenland (66.5-67.5°N), where multiple colour variants exist, white male Gyrfalcons fathered significantly earlier clutches than grey males. No significant association was observed between female colour and lay date. However, significantly more offspring were produced by both male and female white Gyrfalcons than by grey variants when controlling for lay date, and silver Gyrfalcons produced an intermediate number of offspring for both sexes. This pattern was further supported by breeding plumage colour pairings. Grey females paired with grey males nested significantly later in the season and produced fewer offspring than those paired with white males, whereas no difference in lay date or offspring number was found between white males paired with white or with grey females. The difference in the number of offspring produced at each nest-site was also inversely correlated with the distance to the nearest neighbouring nest, and grey males nested in closer proximity to other nests compared with white and silver colour variants. These results suggest that factors associated with territory occupancy and timing of breeding may regulate reproductive success differently between colour variants, with directional selection favouring light-coloured Gyrfalcons and resulting in earlier lay date and a high frequency of white plumage colour variants in this population. Although gene flow exists between our study population and those further north (>75°N), white Gyrfalcons prevail where the breeding season duration is even shorter, suggesting that nesting chronology in combination with genetic drift may play an important role in influencing plumage colour polymorphism among Gyrfalcon populations.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Timing of breeding and offspring number covary with plumage colour among GyrfalconsFalco rusticolus

Johnson

Burnham

2012

Ibis

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“…Within our study area in the Avanersuaq District, an ameliorating climate has been suggested as a contributing factor to recent increases in both local common eider and peregrine falcon populations, and earlier nest initiation dates for gyrfalcon (Burnham and Burnham 2011;Burnham et al 2012a, b). As daily temperatures increase, the number of days available to breed and successfully raise offspring also increases, thereby allowing for a northward expansion among many species.…”

Section: Possible Mechanisms For Observed Abundance Changesmentioning

confidence: 93%

New species records and changes in abundance of waterfowl in northwest Greenland

Burnham¹,

Sinnett

Johnson

et al. 2014

Polar Biol

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Breeding populations of Nearctic and Palearctic waterfowl have undergone significant changes in abundance and distribution over the past 50 years. The Avanersuaq District in northwest Greenland is home to an assemblage of waterfowl from both geographic areas; however, minimal historic or current information is available on species abundance. In 2008 and 2009, we conducted field surveys in Greenland from 76.00°to 77.35°N for breeding and non-breeding waterfowl and have collected anecdotal field notes of avian observations over a 20-year period (1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012). During these periods, we documented the first observation of a Ross's goose (Chen rossii) and the first confirmed breeding by lesser snow geese (Chen caerulescens caerulescens) in Greenland. Northern pintails (Anas acuta) were observed for the first time in northwest Greenland, and a previously unknown breeding location for brent geese (Branta bernicla hrota) was also identified. Local populations of greater snow (C. c.) and Canada geese (B. canadensis) have increased in size. The Booth Sound and Drown Bay wetland areas and many islands throughout the Avanersuaq District were identified as critical habitat for both breeding and non-breeding waterfowl. Further increases in waterfowl abundance, including more frequent rare and new visitors, are likely in the study area as breeding populations further south continue to increase and an ameliorating climate allows for a longer breeding season. These results will prove useful as a baseline for comparisons with future surveys.

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“…If the research question involves the growth or survival of raptor nestlings, then it is best to survey prey during the brood rearing period. This can depend on the study population in question, but for Gyrfalcons brood rearing generally occurs from late May through early August (Poole and Bromley 1988, Burnham and Burnham 2011, Milligan and Powell 2014. Conversely, one may wish to determine the effects of prey abundance on the occupancy of nest sites, or the prelaying body condition and phenology of breeding adults, or nest abandonment during incubation.…”

Section: Designing and Implementing A Distance Sampling Surveymentioning

confidence: 99%