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Adults have more male-biased sex ratios than first-winter juveniles in wintering duck populations

Avian Research 2021年第4期12卷 623-637页

作者： Kevin A.Wood Kane Brides Maurice E.Durham Richard D.Hearn wildfowl&wetlands trust SlimbridgeGloucestershire GL27BTUK

Background:The long-term monitoring of demographic changes in waterbird populations remains limited,but such information can be valuable for conservationists and waterbird *** sex ratios can indicate differences in survival rates between *** particular,differences in the sex ratios of fledged juveniles and adults can provide insight into the development of male bias among ***:In this study,we used data from individual birds captured over a 57-year period to assess the extent,and temporal variability in male bias in nine populations of ducks wintering in the United Kingdom:Gadwall(Mareca strepera),Northern Mallard(Anas platyrhynchos),Northern Pintail(Anas acuta),Common Pochard(Aythya ferina),Common Shelduck(Tadorna tadorna),Northern Shoveler(Spatula clypeata),Eurasian Teal(Anas crecca),Tufted Duck(Aythya fuligula),and Eurasian Wigeon(Mareca penelope).Results:Overall,eight of these populations were significantly male-biased and adults were more male-biased than first-winter juveniles for all nine *** increased male bias among adults is consistent with the hypothesis that factors such as higher mortality of reproductive-age females during the breeding season is a major cause of male bias in duck ***,such predation cannot explain the male bias detected in first-winter juveniles in four of the *** temporal trends in male bias differed between adults and first-winter juveniles in Northern Mallard,Northern Pintail,Common Pochard,Common Shelduck,Eurasian Teal,Tufted Duck,and Eurasian *** the study period we found increased male bias among adult Northern Mallard,Northern Pintail,Common Pochard,Common Shelduck,and Tufted Duck as well as both adult and first-winter juvenile Northern ***:We provide evidence that among wintering duck populations,sex ratios are typically male-biased,with adults exhibiting stronger male-biased sex ratios than first-winter *** monitoring

关键词： Anseriformes Bird ringing Demography Population structure Sex ratio Waterfowl

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Using accelerometry to compare costs of extended migration in an arctic herbivore

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Current Zoology 2017年第6期63卷 667-674页

作者： Mitch D. WEEGMAN Stuart BEARHOP Geoff M. HILTON Alyn J. WALSH Larry GRIFFIN Yehezkel S. RESHEFF Ran NATHAN Anthony DAVID Fox Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Cornwall Campus Penryn TR109EZ UK wildfowl & wetlands trust Slimbridge Gloucester GL2 7BT UK National Parks and Wildlife Service Wexford Wildfowl Reserve North Slob Wexford Ireland wildfowl & wetlands trust Caerlaverock Wetland Centre Eastpark Farm Caerlaverock Durnfriesshire DG1 4RS UK Department of Ecology Evolution and Behavior The Hebrew University of Jerusalem Givat Ram Jerusalem 91904 Israel Department of Bioscience Aarhus University Kale Grenavej 14 RФnde DK-8410 Denmark Present address: School of Natural Resources University of Missouri Columbia MO 65211 USA.

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.

关键词： avian migration cost energy expenditure global positioning system-acceleration tracking devices Greenland whitefronted geese individual decision-making proportion of time feeding.

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Aggressive behavioural interactions between swans(Cygnus spp.)and other waterbirds during winter:a webcam-based study

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Avian Research 2020年第3期11卷 310-325页

作者： Kevin A.Wood Phoebe Ham Jake Scales Eleanor Wyeth Paul E.Rose wildfowl&wetlands trust Slimbridge Wetland CentreSlimbridgeGloucestershire GL27BTUK Centre for Research in Animal Behaviour PsychologyWashington SingerUniversity of ExeterPerry RoadExeterDevon EX44QGUK University Centre Sparsholt College SparsholtHampshire SO212NFUK

Background:Our understanding of any impacts of swans on other waterbirds(including other swans),and potential effects on waterbird community structure,remain limited by a paucity of fundamental behavioural and ecological data,including which species swans interact aggressively with and how frequently such interactions ***:Behavioural observations of aggression by swans and other waterbirds in winters 2018/2019 and 2019/2020,were carried out via live-streaming webcams at two wintering sites in the *** occurrence sampling was used to identify all aggressive interactions between conspecific or heterospecifics individuals,whilst focal observations were used to record the total time spent by swans on aggressive interactions with other *** tests were then used to assess whether the proportion of intraspecific aggressive interactions of each species differed from 0.5(which would indicate equal numbers of intraspecific and interspecific interactions).Zero-inflated generalized linear mixed effects models(ZIGLMMs)were used to assess between-individual variation in the total time spent by swans on aggressive interactions with other ***:All three swan species were most frequently aggressive towards,and received most aggression from,their *** 10-min focal observations showed that Whooper(Cygnus cygnus)and Bewick’s Swans(*** bewickii)spent 13.8±4.7 s(means±95%CI)and 1.4±0.3 s,respectively,on aggression with other *** durations were equivalent to 2.3%and 0.2%of the Whooper and Bewick’s Swan time-activity budgets,*** selection indicated that the time spent in aggressive interactions with other swans was best-explained by the number of other swans present for Whooper Swans,and an interactive effect of time of day and winter of observation for Bewick’s ***,the relationship between swan numbers and Whooper Swan aggression times was not strong(R2=19.3%).Conclusions:Whilst swans do exhibit some agg

关键词： Aggression Agonistic behaviour Bewick’s Swans Intraspecific versus interspecific competition Remote data collection Waterfowl Whooper Swans

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Behavioural and energetic consequences of competition among three overwintering swan(Cygnus spp.)species

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Avian Research 2021年第4期12卷 707-721页

作者： Kevin A.Wood Julia L.Newth Geoff M.Hilton Eileen C.Rees wildfowl&wetlands trust SlimbridgeGloucestershire GL27BTUnited Kingdom Centre for Ecology and Conservation/Environment and Sustainabil-ity Institute College of Life and Environmental SciencesUniversity of ExeterExeter TR109EZUnited Kingdom Department of Zoology University of CambridgeDowning StreetCambridge CB23EJUnited Kingdom

Background:Winter numbers of the northwest European population of Bewick's Swans(Cygnus columbianus bewickii)declined recently by c.40%.During the same period,numbers of two sympatric and ecologically-similar congeners,the Mute Swan(Cygnus olor)and Whooper Swan(Cygnus cygnus)showed increases or *** has been suggested that these opposing population trends could have a causal relationship,as Mute and Whooper Swans are larger and competitively dominant to Bewick's Swans in foraging *** so,effects of competition of Mute and Whooper Swans on Bewick's Swans should be detectable as measurable impacts on behaviour and ***:Here,we studied the diurnal behaviour and energetics of 1083 focal adults and first-winter juveniles("cygnets")of the three swan species on their winter grounds in eastern *** analysed video recordings to derive time-activity budgets and these,together with estimates of energy gain and expenditure,were analysed to determine whether individual Bewick's Swans altered the time spent on key behaviours when sharing feeding habitat with other swan species,and any consequences for their energy expenditure and net energy ***:All three swan species spent a small proportion of their total time(0.011)on aggressive interactions,and these were predominantly intraspecific(≥0.714).Mixed-effects models indicated that sharing feeding habitat with higher densities of Mute and Whooper Swans increased the likelihood of engaging in aggression for cygnet Bewick's Swans,but not for *** levels of interspecific competition decreased the time spent by Bewick's Swan cygnets on foraging,whilst adults showed the opposite *** among low densities of conspecifics(

关键词： Avian behaviour Energy expenditure Ethology Interference competition Interspecific interactions Time activity budgets Video observations

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Climate change and contrasting plasticity in timing of a two-step migration episode of an Arctic-nesting avian herbivore

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Current Zoology 2014年第2期60卷 233-242页

作者： Anthony David FOX Mitch D.WEEGMAN Stuart BEARHOP GeoffM.HILTON Larry GRIFFIN David A.STROUD Alyn WALSH Department of Bioscience Aarhus University Kalo Grenavej 14 DK-8410 Ronde Denmark Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Cornwall CampusTR10 9EZ UK wildfowl and wetlands trust Slimbridge Gloucester GL2 7BT UK wildfowl and wetlands trust Eastpark Farm Caerlaverock Dumfriesshire DGI 4RS UK Greenland White-fronted Goose Study c/o Spring Meadows Taylors Green Warmington Peterborough PE8 6TG UK National Parks and Wildlife Service Wexford Wildfowl Reserve North Slob Wexford Ireland

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].

关键词： Anser albifronsflavirostris Climate mismatch Greenland white-fronted geese Migration phenology Vernalmigration

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Priority sites and conservation gaps of wintering waterbirds in the Yangtze River floodplain

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Journal of Geographical Sciences 2020年第10期30卷 1617-1632页

作者： XIA Shaoxia YU Xiubo LEI Jinyu HEARN Richard SMITH Bena LEI Gang XIE Ping Key Laboratory of Ecosystem Network Observation and Modelling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Living Yangtze Program World Wide Fund for Nature ChinaWuhan 430060China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China wildfowl&wetlands trust SlimbridgeGloucestershire GL27BTUnited Kingdom State Key Laboratory for Freshwater Ecology and Biotechnology of China Institute of HydrobiologyCASWuhan 430072China

The Yangtze River floodplain is critical for migratory waterbirds along the East Asian-Australasian Flyway (EAAF). Greater awareness of its global importance is urgently needed to ensure waterbird populations remain in favourable conservation status, as well as the enhancement of wider wetland biodiversity within this region. The designation of protected wetland areas and building a green ecological corridor in the Yangtze floodplain is now becoming a critical issue of interest to the Chinese government. Priority sites in this area were identified based on the criteria used to identify sites that qualify as wetlands of International Importance (Ramsar Sites) and Important Bird and Biodiversity Areas (IBAs) by using multi-source data. The results show that 140 of the sites surveyed are priority sites. The Importance Index (/) for the whole floodplain decreased slightly from 2001–2005 and an unbalanced distribution pattern is evident with Jiangxi and Hunan provinces significantly higher than the other provinces in the floodplain. Although more than 60% of the priority sites are currently located outside protected areas, the average Conservation Effectiveness Index (C) of the whole floodplain is 75.6%, which suggests the coverage of protected areas for most wintering waterbird population is reasonable. Conservation of the Yangtze River floodplain needs to be further strengthened due to declining waterbird abundances and the mismatch between the distribution of protected areas and their importance for wintering waterbirds. A comprehensive system for priority site identification and protection and scientific review is needed. Multi-sourced data from regular, systematic and coordinated monitoring of waterbird distribution and abundance across the EAAF, as well as national scale citizen science programmes are also critically important.

关键词： wintering waterbirds Yangtze River floodplain priority site feeding guild

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