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Ecology, management and conservation in natural and modified habitats
RESEARCH ARTICLE

Deslorelin implants control fertility in urban brushtail possums (Trichosurus vulpecula) without negatively influencing their body-condition index

Cheryl A. Lohr A C , Harriet Mills A , Helen Robertson B and Roberta Bencini A
+ Author Affiliations
- Author Affiliations

A School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6008, Australia.

B Perth Zoo, 20 Labouchere Road, South Perth, WA 6151, Australia.

C Corresponding author. Email: cheryl.lohr@gmail.com

Wildlife Research 36(4) 324-332 https://doi.org/10.1071/WR08050
Submitted: 3 April 2008  Accepted: 18 February 2009   Published: 1 June 2009

Abstract

Wild brushtail possums (Trichosurus vulpecula) occur in large numbers in the grounds of Perth Zoo, Western Australia. These possums are a problem because they consume feed the zoo buys for its captive animals, damage seedlings and trees and many need to be treated for injuries sustained during fights with conspecifics. A contraceptive implant, which contains the gonadotrophin releasing hormone (GnRH) agonist deslorelin, could be a potential method of managing this population. We tested the efficacy of the implant and its impact on the body-condition index of treated possums with Kaplan–Meier analysis and a mixed model with residual maximum likelihood. We implanted 60 female possums with deslorelin and monitored reproductive success of treated and untreated possums for the following 18 months. At the conclusion of the study, 80% of 20 treated females recaptured had shown no evidence of breeding activity, giving an average minimum duration of effective contraception of 381 days. The implant did not have a negative impact on the body-condition index of treated possums during the course of the study. Our results suggest that deslorelin implants could be an effective management tool for brushtail possums at Perth Zoo and in other urban environments.


Acknowledgements

Our most sincere thanks go to the staff at Perth Zoo, particularly Dr Karen Payne, Dr Simone Vitali, Dr Paul Eden, Dr Rebecca Vaughan and Caroline Lawrence. Also to Kevin Murray, for his help with the statistics and to those people who volunteered to help with the field work. Our thanks also go to the referees of this paper for their input. All experimental procedures described in this paper were approved by The University of Western Australia Animal Ethics Committee (05/100/514) and the Perth Zoo Animal Ethics Committee (PZRE 2005–25).


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