USF St. Petersburg campus Faculty Publications

Population-level declines in Australian predators caused by an invasive species

SelectedWorks Author Profiles:

J. Sean Doody

Document Type

Article

Publication Date

2009

ISSN

1367-9430

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.

Comments

Citation only. Full-text article is available through licensed access provided by the publisher. Members of the USF System may access the full-text of the article through the authenticated link provided.

Language

en_US

Publisher

WILEY-BLACKWELL PUBLISHING, INC

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Share

COinS