Colour Morphs in the Collared Pygmy Owl Glaucidium brodiei are Age-Related, not a Polymorphism

[摘要] ColourmorphvariationiswidelyobservedinowlsandseveralstudieshavedescribeddifferencesInlifehistorytraitsamongthemorphs.Traditionally,Glaucidiumowlsaredescribedashavingtwocolourmorphs,rufousandgrey,whicharesupposedlyindependentofageorsex.During2010–2012,nestboxesweresetupinordertostudythebasiclifehistoryofCollaredPygmyOwlsGlaucidiumbrodiei.Webandedthepopulationandfollowedsomeofthefledglingsfornearlytwoyears.Ourresults—incombinationwithdatafrommuseumspecimens—clearlyshowthatthecolourmorphInCollaredPygmyOwlsisage-dependent,changingfromtheoriginalfledglingplumage(2–3monthsafterhatching)totherufousmorph(4–7monthsafterhatching),andfinallytothedefinitivegreyplumage.Ourresultsrejectthelong-standingpolymorphismhypothesisforthepygmyowl.Weconcludethattheageofthebirdsshouldbeconsideredbeforeacolourpolymorphismcanbeconfirmed,especiallyinsecretivenocturnalspecies.Thecaseofwithin-speciespolymorphismmightbeoverstatedinStrigiformes.

[学科分类] 动物科学

[关键词] Strix Aluco