Selecting the best:Interspecific and age-related diet differences among sympatric steppe passerines  

作　　者：Julia Zurdo Paula Gomez-Lopez Adrian Barrero Daniel Bustillo-de la Rosa Julia Gomez-Catasús Margarita Reverter Cristian Perez-Granados Manuel B.Morales Juan Traba 

机构地区：[1]Terrestrial Ecology Group,Department of Ecology,Universidad Autonoma de Madrid(TEG-UAM),Madrid,Spain [2]Centro de Investigacion en Biodiversidady Cambio Global,Universidad Autonoma de Madrid(CIBC-UAM),Madrid,Spain [3]Ecology Department/IMEM“Ramon Margalef”,Universidad de Alicante,Alicante,Spain

出　　处：《Avian Research》2023年第4期611-622,共12页鸟类学研究（英文版）

基　　金：supported by the European Commission LIFE Ricotí(LIFE15-NAT-ES-000802);LIFE Connect Ricotí(LIFE20-NAT-ES000133)projects;This is a contribution to the Excellence Network Remedinal TE-CM(S2013/MAE2719);JG-C is funded by a Margarita Salas postdoctoral fellowship(CA4/RSUE/2022-00205)。

摘　　要：Parental food provisioning is crucial for the growth and survival of offspring.Growth rate depends on food quality and food supplied to offspring may differ from what adults use for their own.In the case of steppe passerine birds,detailed characterization on nestling dietary composition,as well as prey choice and resource partitioning among species,is a pending subject.Dietary differences between nestlings and adults remain also largely unexplored.By using faecal DNA metabarcoding,we described the diet of nestlings and adults of five shrub-steppe passerine species over the 2017–2019 breeding seasons in central Spain.We also monitored arthropod availability in the field to assess dietary selection.We expected interspecific dietary differences to limit competition for food resources among sympatric species,as well as parental selection of high quality prey for nestlings.We also predicted age-related differences,with nestlings being fed nutrient-rich prey more frequently than adults.The main arthropod orders provisioned to nestlings were Orthoptera,Julida,Araneae and Lepidoptera.Nestlings of the different species showed high interspecific diet overlap,indicating both a coincidence in growth needs among bird species and no or little limitation of the most profitable resources during the breeding season.Adults of all species showed higher diet richness than nestlings,and age-related differences in prey composition were mainly driven by the selection of the most easily digestible,larger protein-and calcium-rich prey for nestlings,which may favour their rapid growth,and avoiding highly sclerotized and less nutritional prey such as ants.Our study sheds light on the basic ecology and conservation of these declining steppe birds,indicating that interspecific competition may not be a major factor during the breeding season.Given the current global decline of arthropods,further long-term research would be necessary,along with the implementation of effective conservation measures that ensure a sufficient availability of res

关 键 词：18S Faecal material Nestling diet Prey choice Resource partitioning 

分 类 号：Q958[生物学—动物学]