Greenland white-fronted geese Anser albifrons flavirostris wintering in Britain and Ireland migrate over the sea for 700-1200 km to stage 3-5 weeks in Iceland in spring, continuing a similar distance over the sea and ...
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Greenland white-fronted geese Anser albifrons flavirostris wintering in Britain and Ireland migrate over the sea for 700-1200 km to stage 3-5 weeks in Iceland in spring, continuing a similar distance over the sea and Greenland Ice Cap to West Greenland breeding grounds. During 1969 to 2012, the geese advanced the mean departure date from Ireland by 15 days, during which time also they attained threshold fat stores earlier as well as departing in fatter condition. Over that period, Iceland spring-staging geese shifted from consuming underground plant storage organs to grazing managed hayfields, which provide fresh grass growth despite sub-zero temperatures, when traditional natural foods are inaccessible in frozen substrates. In 2012 and 2013, geese arrived three weeks earlier to Iceland, in fatter condition and accumulated fat significantly slower than in 1997-1999 and 2007. Although geese accumulated sufficient fat stores earlier in Iceland in 2007, 2012 and 2013, they departed around the same date as in 1997-1999, prolonging spring staging by three weeks. Plasticity in winter departure dates is likely due to improved winter feeding conditions (enabling earlier departure in better condition) and a novel predictable food resource in Iceland. Greenland white-fronted geese attained threshold fat stores in Iceland earlier, but remained rather than departing earlier to Greenland. Despite arriving earlier in Iceland, arrival dates on the breeding areas have not changed since the 1880s, presumably because of relatively constant cool springs and heavy snowfall in West Greenland during recent years [Current Zoology 60 (2): 233-242, 2014].
Understanding how individuals manage costs during the migration period is challenging because individuals are difficult to follow between sites; the advent of hybrid Global Positioning Systemacceleration (ACC) track...
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Understanding how individuals manage costs during the migration period is challenging because individuals are difficult to follow between sites; the advent of hybrid Global Positioning Systemacceleration (ACC) tracking devices enables researchers to link spatial and temporal attributes of avian migration with behavior for the first time ever. We fitted these devices on male Greenland white-fronted geese Anser albifrons flavirostris wintering at 2 sites (Loch Ken, Scotland and Wexford, Ireland) to understand whether birds migrating further during spring fed more on winter- ing and staging areas in advance of migration episodes. Although Irish birds flew significantly further (ca. 300 kin) than Scottish birds during spring, their cumulative hours of migratory flight, flight speed during migration, and overall dynamic body ACC (i.e., a proxy for energy expenditure) were not significantly different. Further, Irish birds did not feed significantly more or expend significantly more energy in advance of migration episodes. These results suggest broad individual plasticity in this species, although Scottish birds arriving on breeding areas in Greenland with greater energy stores (because they migrated less) may be better prepared for food scarcity, which might increase their reproductive success.
Background:Many species of owls(Strigidae) represent cryptic species and their taxonomic study is in *** recent years,two new species of owls of the genus Strix have been described from the Middle East by different re...
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Background:Many species of owls(Strigidae) represent cryptic species and their taxonomic study is in *** recent years,two new species of owls of the genus Strix have been described from the Middle East by different research *** has been suggested that one of these species,***,is not a valid species but taxonomic compari?sons have been hampered by the lack of voucher specimens of ***,and the poor state of the holotype of ***:Here we use new DNA sequence data to clarify the taxonomy and nomenclature of the *** *** also report the capture of a single *** sensu stricto in Mashhad,***:A cytochrome b sequence of *** was found to be identical to that of the holotype of ***,indicating that the name *** is best regarded as a junior synonym of *** identity of the *** captured in Mashhad,Iran,was confirmed using DNA sequence *** represents a major(1300 km) range exten?sion of this ***:The population discovered in Oman in 2013 and originally named ‘***' actually represents the rediscovery of ***,which was known from a single specimen and had not been recorded since *** range of *** extends into northeast *** study augments the body of evidence for the recognition of *** and *** as separate species and highlights the importance of using multiple evidence to study cryptic owl species.
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