Moult and Breeding of Captive Northern Hawk Owls Surnia ulula

[摘要] During2003–07,themoultoffourcaptiveNorthernHawkOwlsSurniaululawasstudiedinPoznaÅ„ZoologicalGarden(Poland).Theaviarywasunderdailyobservationandallbreedingeventswererecorded.Itwasrecognizedthatcaptiveconditionsdifferfromthatinthewild(foodavailability,expendedenergy—especiallybymales,andstress)butthestudyofcaptiveowlsallowedadetailedstudyofmoultinrelationtothebreedingcycleofNorthernHawkOwls.Identificationofdatedmoultedfeathersenabledustoreconstructthemoultprocessofprimaries,secondariesandrectrices.Duringthisstudythefourbirdshaddifferentbreedingstatus:single,pairedwithoutbreeding,pairedwithunsuccessfulorsuccessfulbreeding.Inninecases,themoultcorrespondedtopatternsdescribedinliterature.Ineverycaseallprimariesandrectriceswererenewedeachseason.Malesstartedmoulting3–11daysearlierthanfemalesandshedallsecondarieseveryyearwhilefemalesreplacedfrom50–100%ofsecondariesannually.Rateofmoultwasnotrelatedtoambienttemperature.Duringasuccessfulbreedingseason,themoultofbothsexeswastwo-phased:ashortfirstphasewithlowmoultintensitylastinguntilyoungowletsleftthenestboxfollowedbyalonger,moreintensesecondphase.Breedingfemales(egglayingandincubation)startedtomoultafewweeksearlierthannon-breedingfemalesbutcompletedmoultatapproximatelythesamedate.Incontrast,breedingandnon-breedingmaleshadsimilarpatternsofmoultingintensity.

[学科分类] 动物科学

[关键词] Ecological Constraints