Diet composition of the lizard P odarcis lilfordi (Lacertidae) on 2 small islands: an individualresource network approach  

作　　者：Silvia SANTAMARIA Camilla Aviaaja ENOKSEN Jens M.OLESEN Giacomo TAVECCHIA Andreu ROTGER Jose Manuel IGUAL Anna TRAVESET 

机构地区：[1]Global Change Research Group,Inst.Mediterrani d'Estudis Avanqats(CSIC-UIB),C/Miquel Marques 21,E07190 Esporles,Mallorca,Balearic Islands,Spain [2]Section for Ecoinformatics&Biodiversity,Department of Bioscience,Aarhus University,Aarhus C,8000,Denmark [3]Animal Ecology and Demography Group,Inst.Mediterrani d'Estudis Avanqats(CSIC-UIB),C/Miquel Marques 21,Esporles,Mallorca,Balearic Islands,E07190,Spain

出　　处：《Current Zoology》2020年第1期39-49,共11页动物学报（英文版）

基　　金：This work is framed within projects CGL2017-88122-P and BFU 2009-09359 financed by the Spanish Government.

摘　　要：Despite it is widely accepted that intrapopulation variation is fundamental to ecological and evolutionary processes,this level of information has only recently been included into network analysis of species/population interactions.When done,it has revealed non-random patterns in the distribution of trophic resources.Nestedness in resource use among individuals is the most recurrent observed pattern,often accompanied by an absence of modularity,but no previous studies examine bipartite modularity.We use network analysis to describe the diet composition of the Balearic endemic lizard Podarcis lilfordi in 2 islets at population and individual levels,based on the occurrence of food items in fecal samples.Our objectives are to 1)compare niche structure at both levels,2)characterize niche partition using nestedness and modularity,and 3)assess how size,sex,season,and spatial location influence niche structure.At population-level niche width was wide,but narrow at the level of the individual.Both islet networks were nested,indicating similar ranking of the food preferences among individuals,but also modular,which was partially explained by seasonality.Sex and body size did not notably affect diet composition.Large niche overlap and therefore possibly relaxed competition were observed among females in one of the islets and during spring on both islets.Likewise,higher modularity in autumn suggests that higher competition could lead to specialization in both populations,because resources are usually scarce in this season.The absence of spatial location influence on niche might respond to fine-grained spatio-temporally distribution of food resources.Behavioral traits,not included in this study,could also influence resource partitioning.

关 键 词：Balearic Islands INDIVIDUAL diet composition individual-level NETWORK modularity NESTEDNESS population NICHE width 

分 类 号：Q95[生物学—动物学]