Are invasive populations characterized by a broader diet than native populations?
Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
PeerJ
Abstract
Background. Invasive species are among the most significant threats to biodiversity.
The diet of invasive animal populations is a crucial factor that must be considered
in the context of biological invasions. A broad dietary spectrum is a frequently
cited characteristic of invasive species, allowing them to thrive in a wide range of
environments. Therefore, empirical studies comparing diet in invasive and native
populations are necessary to understand dietary requirements, dietary flexibility, and
the associated impacts of invasive species.
Methods. In this study, we compared the diet of populations of the African clawed
frog, Xenopus laevis in its native range, with several areas where it has become invasive.
Each prey category detected in stomach contents was assigned to an ecological category,
allowing a comparison of the diversity of ecological traits among the prey items in the
diet of native and introduced populations. The comparison of diets was also performed
using evenness as a niche breadth index on all sampled populations, and electivity as a
prey selection index for three out of the six sampled populations.
Results. Our results showed that diet breadth could be either narrow or broad in
invasive populations. According to diet and prey availability, zooplankton was strongly
preferred in most cases. In lotic environments, zooplankton was replaced by benthic
preys, such as ephemeropteran larvae.
Discussion. The relative proportions of prey with different ecological traits, and
dietary variability within and between areas of occurrence, suggest that X. laevis is
a generalist predator in both native and invasive populations. Shifts in the realized
trophic niche are observed, and appear related to resource availability. Xenopus laevis
may strongly impact aquatic ecosystems because of its near complete aquatic lifestyle
and its significant consumption of key taxa for the trophic relationships in ponds.
Description
CITATION: Courant, J., et al. 2017. Are invasive populations characterized by a broader diet than native populations?. PeerJ, 5:e3250, doi:10.7717/peerj.3250.
The original publication is available at https://peerj.com
The original publication is available at https://peerj.com
Keywords
African clawed frog, Biodiversity, Ecology, Ecosystem science, Zoology
Citation
Courant, J., et al. 2017. Are invasive populations characterized by a broader diet than native populations?. PeerJ, 5:e3250, doi:10.7717/peerj.3250