Long-Term Trends in Population Density and Reproductive Success of Long-Eared Owl Asio otus in Brandenburg, Germany

[摘要] ThedensityandreproductionofLong-earedOwlsAsiootuswerestudiedina5000hastudyareaofHavelland,Brandenburg,Germanyfrom1984through2007.LocationsofterritorialLong-earedOwlsweremappedfromtheendofJanuaryuntiltheendofApril,countsoffledgedyoungweremadefrommid-MayuntilAugust.Long-earedOwlsnestedinconifergroupingsorisolatedwoodsintheagriculturallandscape.NearlyallnestingtookplaceinnestsofcrowsCorvidae,mainlyinScotsPinePinussylvestristrees.Atotalof867breedingattemptswererecorded;335(36.6%)pairsweresuccessfulinfledging1468young.Thereproductiveoutputwas1.57fledglingsforallpairsthatattemptedtonest,and4.31fledglingspersuccessfulpair.Averagepopulationdensityforthe24yearswas72.7breedingpair/100km2(range40–118breedingpair/100km2).Forthetimeframeof1984–2007therewasnotrendinthenumberofbreedingpairsorinthenumberofyoungfledged.After1990,whenconservation-focusedfarminginthenaturereservebegan,thenumberofyoungfledgedincreasedsignificantly.GrasslandmanagementisconsideredaprincipalconservationmeasureforLong-earedOwlsinBrandenburg.

[学科分类] 动物科学

[关键词] Germany