Definition of spatial positions within foraging Greater White-fronted Geese flocks from an individual's perspective:Cost-benefit dynamics change with the distance to flock edge  

作　　者：Mengzhen Wang Wenwen Chen Chunlin Li Jinming Zhao 

机构地区：[1]School of Life Science,Huaibei Normal University,Huaibei,235000,China [2]School of Resources and Environmental Engineering,Anhui University,Hefei,230601,China

出　　处：《Avian Research》2022年第4期454-460,共7页鸟类学研究（英文版）

基　　金：the National Natural Science Foundation of China(grant numbers 31800325,31970500,31770571);the Anhui Provincial Natural Science Foundation(grant numbers 1808085QC59,1908085QC128).

摘　　要：The costs and benefits of group living are not evenly distributed among individuals that occupy different spatial positions within a group(central or peripheral).However,the definitions of central and peripheral positions may artificially mask the true dynamics of cost and benefit of individuals.Using wintering foraging Greater Whitefronted Geese(Anser albifrons)flocks as our study system,we measured individual spatial position within a flock as distance to the flock edge.First,we tested the effects of distance to edge on the antipredation cost and foraging benefit of individual goose using generalized linear mixed models(GLMMs).Flock size and number of neighbors and their interactions with distance to edge were included as fixed effects in GLMMs.Then we used piecewise regression to determine the threshold value of distance to edge to classify central and peripheral individuals.Our results indicated distance to edge significantly affected percent of time spent on vigilance(vigilance time),percent of time spent on foraging(foraging time)and intake rate(pecks/min),whereas other factors had no effects.We found that the critical distance that predicted changes in behavior was around 2.5 m.Birds 2.5 m or less from the edge of the group were more vigilant,and had less efficient foraging than more central individuals.Behavioral differences between central and peripheral individuals were more easily detected when the birds were classified by the method introduced in this study than by the traditional minimum convex polygon method.Our research provides researchers a dichotomous classification scheme that places individuals into peripheral and central positions from an individual's perspective.

关 键 词：Distance to edge Foraging time Intake rate Spatial position within a group Vigilance time 

分 类 号：Q958[生物学—动物学]