Population-level declines in Australian predators caused by an invasive species
Date
2009
Authors
Doody, J S
Green, B
Rhind, D
Castellano, C.M.
Sims, Rachel
Robinson, T.
Journal Title
Journal ISSN
Volume Title
Publisher
Cambridge University Press
Abstract
The cane toad Bufo marinus has been migrating westward across northern Australia since its introduction as a biological control agent in 1935. It has been implicated in the widespread decline of many native frog-eating predators. To investigate the impacts of this invasive species on native predatory reptiles, annual surveys were conducted from 2001 to 2007 to document variation in the relative abundances of three varanid lizards (Varanus mertensi, Varanus mitchelli and Varanus panoptes) and one crocodile Crocodylus johnstoni species known to consume toads. In addition, the indirect effects of this variation on one agamid lizard Amphibolurus gilberti, a known prey item of V. panoptes, were also examined. Surveys were performed at two sites in northern Australia before and after the arrival of B. marinus. Significant declines in the relative abundances of all three species of varanid lizard were observed following toad arrival. Declines in the abundance of V. panoptes, V. mitchelli and V. mertensi at the two sites ranged 83-96, 71-97 and 87-93%, respectively. In contrast, A. gilberti increased by 23-26%; whereas there were no significant population-level declines in C. johnstoni despite observations of individual effects (i.e. several dead crocodiles with B. marinus in their stomachs). These findings suggest population-level changes in Australian lizards caused by an invasive species.
Description
Keywords
Keywords: abundance; amphibian; invasive species; lizard; population decline; predator-prey interaction; species conservation; Australasia; Australia; Agamidae; Alligator; Amphibia; Amphibolurus; Anura; Bufo marinus; Crocodylidae (all crocodiles); Crocodylus johnso Amphibians; Australia; Conservation; Invasive species; Predator-prey interactions; Relative abundance; Reptiles
Citation
Collections
Source
Animal Conservation
Type
Journal article
Book Title
Entity type
Access Statement
License Rights
Restricted until
2037-12-31
Downloads
File
Description