Sources of Variation in Enterococci and Enterobacteriaceae Loads in Nestlings of a Hole-Nesting Passerine

[摘要] Gutbacterialloadsinaviannestlingsmaybeaffectedbyfactorssuchasclimate,seasonalityandbroodsize.Thereisnopublishedinformationonthissubjectforwildbirds,despiteitspotentialimportancefornestlingwelfareandgrowth.Westudiedtheassociationsofthesefactorswithabundancesoftwocommongutbacterialtypes,enterococciandEnterobacteriaceae,innestlingPiedFlycatchersFicedulahypoleucaincentralSpain.Tothatend,weobtainedfaecalsamplesfrom54broods(102nestlings)onday7and13afterhatching,fordetectionandestimationofbacterialabundance.Enterobacteriaceaeloadsonday7werepositivelycorrelatedwithmeantemperatureduringtheprecedingsevendaysandnegativelycorrelatedwithrainfallandhatchingdate.ThenegativeassociationsofEnterobacteriaceaeloadswithrainfallwereonlyfoundforearlybroods,atlowtemperatures.Enterococciloadsonday7werepositivelyassociatedwithmeantemperature.Onday13,Enterobacteriaceaeloadswerenegativelycorrelatedwithhatchingdate,whileenterococciloadswerepositivelycorrelatedwithmeantemperature.Enterobacteriaceaeareapparentlymoresensitivetoseasonalchangesandclimaticvariationthanenterococci,possiblyinrelationtovariationindietandnutrition.Bycontrast,enterococciareonlysensitivetothermalvariation.TheattainmentoffullthermoregulatorycapacitybynestlingsreducesclimaticeffectsonEnterobacteriaceaeloads.

[学科分类] 动物科学

[关键词] Hatching Date