Reproduction of the Middle Spotted Woodpecker Dendrocopos medius in the Nerussa-Desna Woodland, SW Russia, with Particular Reference to Habitat Fragmentation, Weather Conditions and Food Supply

[摘要] TheNerussa-Desnawoodland(south-westernRussia)isoneofthecoreareasfortheMiddleSpottedWoodpeckerDendrocoposmedius,ahabitatspecialistrestrictedmainlytomatureoakforests.Recentstudieshaveshownalowerbreedingdensityofthespeciesinfragmentedcomparedwithcontinuoushabitat.Toevaluatereproductionasapossiblemechanismunderlyingthefragmentationeffects,westudiedreproductiveperformanceofthespeciesinbothcontinuoushabitatandfragmentedhabitatintheforestedlandscapesoftheNerussa-Desnawoodland.During1997–2001,annualvariationofreproductiveindicesinbothcontinuousandfragmentedhabitatwasinsignificant.Noneoftheindiceswassignificantlylowerinfragmentedhabitatthoughnestlinglossesweresignificantlyhigherinfragments.Timingofbreedingin2000waslaterinfragmentedthancontinuoushabitat,probablyduetodifferentiallandscapephenology.Infragments,fledgingsuccessinayearwasinverselyrelatedtothemeanamountofrain.Onthebasisofindividualpairs,fledglingproductionalsocorrelatedsignificantlyandnegativelywiththeamountofrainduringthenestlingperiodinfood-poorfragmentsonly.In1999–2001,abundanceofLepidopteralarvae,mainfoodfortheMiddleSpottedWoodpeckerduringnestlingphase,variedsignificantlyincontinuoushabitat,whereasinfragmentedhabitatthepatternsofvariationdifferedbetweenfragments.Nosignificantcorrelationwasfoundbetweenlarvaldensityandreproductiveperformanceofindividualpairsineitherhabitat.Largeoakdensity,ahabitatfeaturerelatedtopotentialfoodabundance,washigherinfragmentsthanincontinuoushabitatbutwasnotrelatedtothereproductiveperformance.Thelowerlarvaldensitywithinsometerritoriesinfragmentsasopposedtocontinuoushabitatislikelytoexplainhighernestlingmortalityinfragmentedcomparedtocontinuoushabitat.Generally,wefoundlittleevidenceforloweredreproductiveperformanceinrelationtofragmentation.Therefore,thisseemsunlikelytoberesponsibleforthefragmentation-sensitivepatternsofdensity.

[学科分类] 动物科学

[关键词] Food Supply