Nested species-rich networks of scavenging vertebrates support high levels of interspecific competition.

Published

Journal Article

Disentangling the processes that shape the organization of ecological assemblages and its implications for species coexistence is one of the foremost challenges of ecology. Although insightful advances have recently related community composition and structure with species coexistence in mutualistic and antagonistic networks, little is known regarding other species assemblages, such as those of scavengers exploiting carrion. Here we studied seven assemblages of scavengers feeding on ungulate carcasses in mainland Spain. We used dynamical models to investigate if community composition, species richness and structure (nestedness) affect species coexistence at carcasses. Scavenging networks showed a nested pattern in sites where highly efficient, obligate scavengers (i.e., vultures) were present and a non-nested pattern everywhere else. Griffon Vulture (Gyps fulvus) and certain meso-facultative mammalian scavengers (i.e., red fox, Vulpes vulpes, and stone marten, Martes foina) were the main species contributing to nestedness. Assemblages with vultures were also the richest ones in species. Nested species-rich assemblages with vulture presence were associated with high carcass consumption rates, indicating higher interspecific competition at the local scale. However, the proportion of species stopping the consumption of carrion (as derived from the competitive dynamic model) stabilized at high richness and nestedness levels. This suggests that high species richness and nestedness may characterize scavenging networks that are robust to high levels of interspecific competition for carrion. Some facilitative interactions driven by vultures and major facultative scavengers could be behind these observations. Our findings are relevant for understanding species' coexistence in highly competitive systems.

Full Text

Duke Authors

Cited Authors

  • Sebastián-González, E; Moleón, M; Gibert, JP; Botella, F; Mateo-Tomás, P; Olea, PP; Guimarães, PR; Sánchez-Zapata, JA

Published Date

  • January 2016

Published In

Volume / Issue

  • 97 / 1

Start / End Page

  • 95 - 105

PubMed ID

  • 27008779

Pubmed Central ID

  • 27008779

Electronic International Standard Serial Number (EISSN)

  • 1939-9170

International Standard Serial Number (ISSN)

  • 0012-9658

Digital Object Identifier (DOI)

  • 10.1890/15-0212.1

Language

  • eng