Yearly and Seasonal Variation of Breeding Parameters in a Declining Multi-Brooded Passerine, the Tree Sparrow

Ardea

Juan José Sanz¹  Vicente García-Navas¹ 

[1]1 Área de Zoología, Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Avenida Carlos III s/n 45071 Toledo, Spain

关键词: Seasonal And Inter-annual Trends;   

DOI  :  

学科分类：动物科学

来源: Nederlandse Ornithologische Unie/Netherlands Ornithological Union

【 摘 要 】

Overafive-yearperiodwemonitoredbreedingparametersinacolonyofTreeSparrowsPassermontanusincentralSpain.Thismulti-broodedspeciescanraiseonetothreebroodsperseason.Inthisstudy,weanalyzedinter-broodvariationinreproductivesuccesstoinfertheexistenceofseasonalpatterns.Wealsoexploredinter-annualvariationoflife-historytraits,whichisofparticularinterestinadecliningspeciesliketheTreeSparrow.Inagreementwithourexpectationofamulti-broodedspecies,clutchsizeshowedaquadraticrelationshipwithlayingdate.Wefoundthattheinter-broodintervalvariedsignificantlydependingonthenumberofbreedingattempts,whichsuggeststhatthespeciesmayengageintime-savingbehavioursasreportedforothermulti-broodedpasserines.Nestlingsfromsecondbroodsfledgedinbetterconditionthannestlingsfromfirstandthirdbroods.Fewerfledglingswereproducedinthirdbroodsthaninprecedingbreedingattempts.Thereproductiveoutputofthirdbroodsvariedtoalargeextentamongyears,whereasinter-annualvariationwasmuchlessmarkedinfirstandsecondbroods.Overtheyears,wealsodetectedadecreaseinnestlingsize(tarsusandwinglength),whichwasconsistentamongbreedingattempts.Finally,theproductivityofthecolonyremainedfairlystableoverthestudyperiod.Thispatterncontrastswithnegativepopulationtrendsdetectedbynationalmonitoringprogrammes.Theproximityofwetlandhabitatsinthesurroundingsofourcolony—essentialforadequateinvertebratesforthechicks—issuggestedasamainreasonforthisdifference.

【 授权许可】

Unknown