Common Eider Somateria mollissima Feeding Activity and the Influence of Human Disturbances
[摘要] WestudiedtheimpactofhumandisturbancesonthefeedingactivitiesofCommonEidersSomateriamollissimawinteringinSouthwestGreenland.Eideractivityandhumandisturbances(fastmoving,openboats)wererecordedduring9daysofobservationsinmidandlatewinter2002.Whenmostheavilydisturbed,thefeedingactivityinthestudyareawasreducedupto60%onadailybasis.Atthesametimelocomotionactivitytripled.Logisticregressionanalysesshowedthateidersattemptedtocompensateforlostfeedingopportunitiesbyreschedulingmorefeedingtoperiodswherefeedingconditionswererelativelylessprofitablewithrespecttoothervariables.Whenundisturbed,eidersavoidedfeedingduringhightideandintensifiedfeedingatthestartandattheendoftheday,butthesetendencieswerelevelledoutifeidersweredisturbed.Whendisturbed,thetimeintervalandthedistancetothelastdisturbancewerebothsignificantexplanatoryvariablesforthefeedingactivity.Therewasacumulativeeffectofrepeateddisturbancesonthefeedingactivityifdisturbanceswerecloseintimeandspace(lt;1h,lt;1km).Thedaywiththehighestnumberofdisturbancescoincidedwithobservationsofnocturnalfeedingthefollowingnightandmayindicatethatacriticalthresholdofdisturbanceswasreachedwhereeiderscouldnotrelyonadiurnalfeedingstrategy.
[发布日期] [发布机构]
[效力级别] [学科分类] 动物科学
[关键词] Greenland [时效性]
