Carnivore carcasses are avoided by carnivores
Authored by Wayne M Getz, Marcos Moleon, Carlos Martinez-Carrasco, Oliver C Muellerklein, Carlos Munoz-Lozano, Jose A Sanchez-Zapata
Date Published: 2017
DOI: 10.1111/1365-2656.12714
Sponsors:
European Union
Spanish Ministry of Science and Innovation (MICINN)
Platforms:
Nova
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
https://datadryad.org/resource/doi:10.5061/dryad.qn8d9
Abstract
Ecologists have traditionally focused on herbivore carcasses as study
models in scavenging research. However, some observations of scavengers
avoiding feeding on carnivore carrion suggest that different types of
carrion may lead to differential pressures. Untested assumptions about
carrion produced at different trophic levels could therefore lead
ecologists to overlook important evolutionary processes and their
ecological consequences.
Our general goal was to investigate the use of mammalian carnivore
carrion by vertebrate scavengers. In particular, we aimed to test the
hypothesis that carnivore carcasses are avoided by other carnivores,
especially at the intraspecific level, most likely to reduce exposure to
parasitism.
We take a three-pronged approach to study this principle by: (i)
providing data from field experiments, (ii) carrying out evolutionary
simulations of carnivore scavenging strategies under risks of parasitic
infection, and (iii) conducting a literature-review to test two
predictions regarding parasite life-history strategies.
First, our field experiments showed that the mean number of species
observed feeding at carcasses and the percentage of consumed carrion
biomass were substantially higher at herbivore carcasses than at
carnivore carcasses. This occurred even though the number of scavenger
species visiting carcasses and the time needed by scavengers to detect
carcasses were similar between both types of carcasses. In addition, we
did not observe cannibalism. Second, our evolutionary simulations
demonstrated that a risk of parasite transmission leads to the evolution
of scavengers with generally low cannibalistic tendencies, and that the
emergence of cannibalism-avoidance behaviour depends strongly on
assumptions about parasitebased mortality rates. Third, our literature
review indicated that parasite species potentially able to follow a
carnivore-carnivore indirect cycle, as well as those transmitted via
meat consumption, are rare in our study system.
Our findings support the existence of a novel coevolutionary relation
between carnivores and their parasites, and suggest that carnivore and
herbivore carcasses play very different roles in food webs and
ecosystems.
Tags
Agent-based model
Evolution
Infection
Genetic algorithm
Scavengers
patterns
transmission
Cannibalism
Food webs
Food-web
Parasites
Carrion
Disease risk
Evolution of
host-parasite interactions
Indirect
interactions
Scavenger
Neospora-caninum
Selective force