Nest Survival and Predation in Blue-Fronted Parrots Amazona aestiva: Effects of Nesting Behaviour and Cavity Characteristics

[摘要] InthisstudyweanalysefactorsaffectingnestsurvivalinBlue-frontedParrotsAmazonaaestivabreedingintheChacoregionofnorthernArgentina.Wecombinedtemporalandenvironmentalvariablesinordertodeterminewhichbestexplainvariationinoverallnestsurvivalandinpredationdependentnestsurvival.Wepredictedthathighanddeepcavities,thatareinaccessibletosnakesandotherpredators,wouldhavehighdailysurvivalrates.Wecomparedtherelativeeffectsonnestsurvivaloftimeofthebreedingseason,stageofthenestingcycle,andcharacteristicsofthenestcavity.Wemodelleddailysurvivalrate(DSR)forallobservednests,anddailysurvivalrateforneststhathadbeenpredated(dailysurvivalrateinrelationtopredationexclusively,DSRp).Nestpredationaccountedfor50%ofnestfailures.DSRwasonaverage0.989,translatingintoanapparenthatchingsuccessof0.39.DSRdecreasedwithtimeofbreedingandincreasedwithnestage.DSRpdecreasedwithtimeofbreedingandinclinationofthenestcavityentranceholeandincreasedwithheightfromthegroundoftheentrancehole.TherewasaquadraticeffectofnestageonDSRp,suchthatdailysurvivalwashighestduringincubation,lowestathatchingandtheearlynestlingstage,butincreasingthroughouttheremainderofthenestlingstage.Thiseffectbecamemorepronouncedasthebreedingseasonadvanced.Yearandobservereffectsdidnotaffecttheprobabilityofsurvival.TemporalpatternsandcharacteristicsofthenestcavityexplainedmostofthevariationinnestsurvivalinBlue-frontedParrots,whichhighlightstherelevanceofincludingthesecovariatesinfuturestudiesofnestsurvivalinparrots,andhasimportantmanagementandconservationimplications.

[学科分类] 动物科学

[关键词] Predation