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Feeding specialisation in badgers
Journal
Canadian Journal of
Zoology, Volume 80,Number 1, January 2002, pp. 83-93(11) -
NRC Research Press
Authors
Revilla E.; Palomares F.
Abstract
Several local populations of the otherwise trophic-generalist Eurasian badger
(Meles meles) have been defined as specializing locally on temporally
variable food resources such as earthworms (Lumbricus spp.), olive fruits
(Olea europaea), or young rabbits (Oryctolagus cuniculus), owing
to a lack of correlation between resource availability and use. However,
theoretical models predict that temporal variation in resources reduces the
probability of diet specialization. To understand the relationship between
temporal resource variability and local feeding specialization, we studied
temporal variation in diet composition and diversity (using fecal analysis), the
availability of a temporally stable key resource, and the relation between
consumption and availability of rabbits (key prey) and invertebrates (secondary
prey) for a badger population previously described as specialized on young
rabbits. We found strong variations in the use of different resources (including
young rabbits) and in diet diversity among seasons and years. The main food
resource was young rabbits during winter and spring, fruits in autumn, and
reptiles in summer. Diet diversity was inversely related to consumption of young
rabbits and directly related to consumption of secondary prey (invertebrates).
Consumption of rabbits (both young and adults) was correlated with their
abundance in the field, with a type 3 functional response in the consumption of
young rabbits, which is typical of a generalist to whom alternative prey are
available. There was no relationship between the abundance of invertebrates and
their consumption. Our results show that badgers in the study area were not
locally specialized, therefore care should be taken when referring to a
population as specialized without an adequate test of the predictions.
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