Limited sexual segregation in a dimorphic avian scavenger, the Andean condor.

Autor: Perrig PL; Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, 1630 Linden Dr., Madison, WI, 53706, USA. pperrig@comahue-conicet.gob.ar.; Grupo de Investigaciones en Biología de La Conservación, INIBIOMA (Universidad Nacional del Comahue, CONICET), Quintral, 1250 8400, Bariloche, Rio Negro, Argentina. pperrig@comahue-conicet.gob.ar., Lambertucci SA; Grupo de Investigaciones en Biología de La Conservación, INIBIOMA (Universidad Nacional del Comahue, CONICET), Quintral, 1250 8400, Bariloche, Rio Negro, Argentina., Alarcón PAE; Grupo de Investigaciones en Biología de La Conservación, INIBIOMA (Universidad Nacional del Comahue, CONICET), Quintral, 1250 8400, Bariloche, Rio Negro, Argentina., Middleton AD; Department of Environmental Science, Policy, and Management, University of California-Berkeley, Berkeley, CA, 94720, USA., Padró J; Grupo de Investigaciones en Biología de La Conservación, INIBIOMA (Universidad Nacional del Comahue, CONICET), Quintral, 1250 8400, Bariloche, Rio Negro, Argentina., Plaza PI; Grupo de Investigaciones en Biología de La Conservación, INIBIOMA (Universidad Nacional del Comahue, CONICET), Quintral, 1250 8400, Bariloche, Rio Negro, Argentina., Blanco G; Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC. José Gutiérrez Abascal 2, 28006, Madrid, Spain., Zapata JAS; Departamento de Biología Aplicada, Universidad Miguel Hernández, Elche, 03202, Alicante, Spain., Donázar JA; Estación Biológica de Doñana (CSIC), Américo Vespucio 26, 41092, Sevilla, Spain., Pauli JN; Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, 1630 Linden Dr., Madison, WI, 53706, USA.
Jazyk: angličtina
Zdroj: Oecologia [Oecologia] 2021 May; Vol. 196 (1), pp. 77-88. Date of Electronic Publication: 2021 Apr 10.
DOI: 10.1007/s00442-021-04909-8
Abstrakt: Sexual segregation is widely reported among sexually dimorphic species and generally attributed to intraspecific competition. Prey diversity and human activities can reinforce niche segregation by increasing resource heterogeneity. Here, we explored trophic and spatial sexual segregation in the only avian scavenger that exhibits pronounced sexual size dimorphism (up to 50% difference in body mass) and a highly despotic social system, the Andean condor (Vultur gryphus). We predicted that larger and dominant males would exclude smaller and subordinate females from high-quality resources, leading to sexual segregation particularly in human-dominated landscapes showing increased prey diversity. We compared resource use between females and males across six sites in Argentina featuring a range of prey diversity via stable isotopes analysis of molted feathers (n = 141 individuals). We then focused on two sites featuring contrasting levels of prey diversity and quantified assimilated diet via stable isotopes and space use via GPS monitoring (n = 23 and 12 tagged individuals). We found no clear differences in isotopic niche space, individual variation in isotopic signature, or assimilated diet between females and males. However, there were differences in foraging locations between sexes, with females apparently using areas of fewer food resources more frequently than males. Local conditions defined the dynamics of fine-scale sexual differences in foraging sites; yet, unpredictable and ephemeral carrion resources likely prevent segregation by sexes at the landscape scale. Our study highlights complex dynamics of sexual segregation in vultures and the relevancy of analyses under multiple spatial-temporal scales to explore segregation in social species.
Databáze: MEDLINE
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