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Burnham K.K.,University of Oxford | Burnham K.K.,High Arctic Institute | Newton I.,UK Center for Ecology and Hydrology
Ibis | Year: 2011

Little information exists on the movements of Gyrfalcons Falco rusticolus outside the breeding season, particularly amongst High Arctic populations, with almost all current knowledge based on Low Arctic populations. This study is the first to provide data on summer and winter ranges and migration distances. We highlight a behaviour previously unknown in Gyrfalcons, in which birds winter on sea ice far from land. During 2000-2004, data were collected from 48 Gyrfalcons tagged with satellite transmitters in three parts of Greenland: Thule (northwest), Kangerlussuaq (central-west) and Scoresbysund (central-east). Breeding home-range size for seven adult females varied from 140 to 1197km2 and was 489 and 503km2 for two adult males. Complete outward migrations from breeding to wintering areas were recorded for three individuals: an adult male which travelled 3137km over a 38-day period (83km/day) from northern Ellesmere Island to southern Greenland, an adult female which travelled 4234km from Thule to southern Greenland (via eastern Canada) over an 83-day period (51km/day), and an adult female which travelled 391km from Kangerlussuaq to southern Greenland over a 13-day period (30km/day). Significant differences were found in winter home-range size between Falcons tagged on the west coast (383-6657km2) and east coast (26810-63647km2). Several Falcons had no obvious winter home-ranges and travelled continually during the non-breeding period, at times spending up to 40 consecutive days at sea, presumably resting on icebergs and feeding on seabirds. During the winter, one juvenile female travelled over 4548km over an approximately 200-day period, spending over half that time over the ocean between Greenland and Iceland. These are some of the largest winter home-ranges ever documented in raptors and provide the first documentation of the long-term use of pelagic habitats by any falcon. In general, return migrations were faster than outward ones. This study highlights the importance of sea ice and fjord regions in southwest Greenland as winter habitat for Gyrfalcons, and provides the first detailed insights into the complex and highly variable movement patterns of the species. © 2011 The Authors. Ibis © 2011 British Ornithologists' Union. Source


Burnham K.K.,High Arctic Institute | Sinnett D.R.,United Road Services | Johnson J.A.,University of North Texas | Burnham J.L.,Augustana College at Rock Island | And 2 more authors.
Polar Biology | Year: 2014

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 (1993-2012). 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. © 2014 Springer-Verlag Berlin Heidelberg. Source


Johnson J.A.,University of North Texas | Talbot S.L.,U.S. Geological Survey | Sage G.K.,U.S. Geological Survey | Burnham K.K.,High Arctic Institute | And 5 more authors.
PLoS ONE | Year: 2010

Background: Our ability to monitor populations or species that were once threatened or endangered and in the process of recovery is enhanced by using genetic methods to assess overall population stability and size over time. This can be accomplished most directly by obtaining genetic measures from temporally-spaced samples that reflect the overall stability of the population as given by changes in genetic diversity levels (allelic richness and heterozygosity), degree of population differentiation (FST and DEST), and effective population size (Ne). The primary goal of any recovery effort is to produce a longterm self-sustaining population, and these genetic measures provide a metric by which we can gauge our progress and help make important management decisions. Methodology/Principal Findings: The peregrine falcon in North America (Falco peregrinus tundrius and anatum) was delisted in 1994 and 1999, respectively, and its abundance will be monitored by the species Recovery Team every three years until 2015. Although the United States Fish and Wildlife Service makes a distinction between tundrius and anatum subspecies, our genetic results based on eleven microsatellite loci suggest limited differentiation that can be attributed to an isolation by distance relationship and warrant no delineation of these two subspecies in its northern latitudinal distribution from Alaska through Canada into Greenland. Using temporal samples collected at Padre Island, Texas during migration (seven temporal time periods between 1985-2007), no significant differences in genetic diversity or significant population differentiation in allele frequencies between time periods were observed and were indistinguishable from those obtained from tundrius/anatum breeding locations throughout their northern distribution. Estimates of harmonic mean Ne were variable and imprecise, but always greater than 500 when employing multiple temporal genetic methods. Conclusions/Significance: These results, including those from simulations to assess the power of each method to estimate Ne, suggest a stable or growing population, which is consistent with ongoing field-based monitoring surveys. Therefore, historic and continuing efforts to prevent the extinction of the peregrine falcon in North America appear successful with no indication of recent decline, at least from the northern latitude range-wide perspective. The results also further highlight the importance of archiving samples and their use for continual assessment of population recovery and long-term viability. Source


Johnson J.A.,University of North Texas | Ambers A.D.,University of North Texas | Burnham K.K.,High Arctic Institute
Journal of Heredity | Year: 2012

Genetic variation at the melanocortin-1 receptor (MC1R) gene is correlated with melanin color variation in a few reported vertebrates. In Gyrfalcon (Falco rusticolus), plumage color variation exists throughout their arctic and subarctic circumpolar distribution, from white to gray and almost black. Multiple color variants do exist within the majority of populations; however, a few areas (e.g., northern Greenland and Iceland) possess a single color variant. Here, we show that the white/melanic color pattern observed in Gyrfalcons is explained by allelic variation at MC1R. Six nucleotide substitutions in MC1R resulted in 9 alleles that differed in geographic frequency with at least 2 MC1R alleles observed in almost all sampled populations in Greenland, Iceland, Canada, and Alaska. In north Greenland, where white Gyrfalcons predominate, a single MC1R allele was observed at high frequency (>98%), whereas in Iceland, where only gray Gyrfalcons are known to breed, 7 alleles were observed. Of the 6 nucleotide substitutions, 3 resulted in amino acid substitutions, one of which (Val128Ile) was perfectly associated with the white/melanic polymorphism. Furthermore, the degree of melanism was correlated with number of MC1R variant alleles, with silver Gyrfalcons all heterozygous and the majority of dark gray individuals homozygous (Ile128). These results provide strong support that MC1R is associated with plumage color in this species. © 2012 The American Genetic Association. Source


Burnham K.K.,High Arctic Institute | Johnson J.A.,University of North Texas | Konkel B.,High Arctic Institute | Burnham J.L.,Augustana College at Rock Island
Arctic | Year: 2012

Common eider (Somateria mollissima) populations in Greenland severely declined throughout the 20th century. As a result, in 2001, harvest regulations were changed and the length of the hunting season was reduced. Recent data suggest that these changes have been successful, and population regrowth is occurring. In the Avanersuaq District, northwest Greenland, only one systematic survey quantifying the number of nesting eiders had previously been conducted, in 1997 and 1998. Although this district had historically been identified as having the largest number of breeding eiders in Greenland, the 1997 - 98 survey results showed a relatively small estimated population of 5000 pairs. However, it is not known to what extent changes in hunting regulations have affected nesting abundance in this area. Therefore, the Avanersuaq District was system- atically resurveyed during the 2009 breeding season, approximately 11 years after the previous survey. These results showed that the population had increased to 5.4 times its 1997 - 98 size, with an annual compounded growth rate of 15.3%. On a single island, nearly 4500 active nests were observed. Five islands had more than 2600 nests each and comprised 75% of the total nests counted. Along with historical information to account for additional nesting habitat not surveyed, the observed population growth rate from this study suggests that the overall Avanersuaq common eider breeding population size ranges from 25 000 to 30 000 pairs, or roughly half of the total estimated West Greenland breeding population. Despite the significance of the Avanersuaq District as a breeding area for common eiders, we have only limited information about this population. The effects of recent extensions of the hunting season on this population are also unknown, and the only wintering location information is based on a few individuals banded in the 1920s and 1940s. Additional research on migratory movements is suggested before any further changes are made to hunting regulations. © The Arctic Institute of North America. Source

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