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Research article - Peer-reviewed, 2020

Network structure of vertebrate scavenger assemblages at the global scale: drivers and ecosystem functioning implications

Sebastian-Gonzalez, Esther; Morales-Reyes, Zebensui; Botella, Francisco; Naves-Alegre, Lara; Perez-Garcia, Juan M.; Mateo-Tomas, Patricia; Olea, Pedro P.; Moleon, Marcos; Barbosa, Jomar M.; Hiraldo, Fernando; Arrondo, Eneko; Donazar, Jose A.; Cortes-Avizanda, Ainara; Selva, Nuria; Lambertucci, Sergio A.; Bhattacharjee, Aishwarya; Brewer, Alexis L.; Abernethy, Erin F.; Turner, Kelsey L.; Beasley, James C.;
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Abstract

The organization of ecological assemblages has important implications for ecosystem functioning, but little is known about how scavenger communities organize at the global scale. Here, we test four hypotheses on the factors affecting the network structure of terrestrial vertebrate scavenger assemblages and its implications on ecosystem functioning. We expect scavenger assemblages to be more nested (i.e. structured): 1) in species-rich and productive regions, as nestedness has been linked to high competition for carrion resources, and 2) regions with low human impact, because the most efficient carrion consumers that promote nestedness are large vertebrate scavengers, which are especially sensitive to human persecution. 3) We also expect climatic conditions to affect assemblage structure, because some scavenger assemblages have been shown to be more nested in colder months. Finally, 4) we expect more organized assemblages to be more efficient in the consumption of the resource. We first analyzed the relationship between the nestedness of the scavenger assemblages and climatic variables (i.e. temperature, precipitation, temperature variability and precipitation variability), ecosystem productivity and biomass (i.e. NDVI) and degree of human impact (i.e. human footprint) using 53 study sites in 22 countries across five continents. Then, we related structure (i.e. nestedness) with its function (i.e. carrion consumption rate). We found a more nested structure for scavenger assemblages in regions with higher NDVI values and lower human footprint. Moreover, more organized assemblages were more efficient in the consumption of carrion. However, our results did not support the prediction that the structure of the scavenger assemblages is directly related to climate. Our findings suggest that the nested structure of vertebrate scavenger assemblages affects its functionality and is driven by anthropogenic disturbance and ecosystem productivity worldwide. Disarray of scavenger assemblage structure by anthropogenic disturbance may lead to decreases in functionality of the terrestrial ecosystems via loss of key species and trophic facilitation processes.

Keywords

carrion; consumption rate; ecological networks; global change; macroecology; NDVI

Published in

Ecography
2020,
Publisher: WILEY

Authors' information

Sebastian-Gonzalez, Esther
Univ Miguel Hernandez
Morales-Reyes, Zebensui
Univ Miguel Hernandez
Botella, Francisco
Univ Miguel Hernandez
Naves-Alegre, Lara
Univ Miguel Hernandez
Perez-Garcia, Juan M.
Univ Miguel Hernandez
Mateo-Tomas, Patricia
Univ Coimbra
Olea, Pedro P.
Univ Autonoma Madrid
Moleon, Marcos
Univ Granada
Barbosa, Jomar M.
CSIC
Hiraldo, Fernando
CSIC
Arrondo, Eneko
CSIC
Donazar, Jose A.
CSIC
Cortes-Avizanda, Ainara
CSIC
Selva, Nuria
Polish Acad Sci
Lambertucci, Sergio A.
Univ Nacl Comahue
Bhattacharjee, Aishwarya
CUNY
Brewer, Alexis L.
CUNY Queens Coll
Abernethy, Erin F.
Oregon State Univ
Turner, Kelsey L.
Univ Georgia
Beasley, James C.
Univ Georgia
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Sustainable Development Goals

SDG15 Life on land

UKÄ Subject classification

Ecology

Publication Identifiers

DOI: https://doi.org/10.1111/ecog.05083

URI (permanent link to this page)

https://res.slu.se/id/publ/105697