CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > The Rangeland Journal   
The Rangeland Journal
http://www.austrangesoc.com.au/
  Rangeland Ecology & Management
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Structure
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Sample Issue
Call for Papers
For Authors
General Information
Notice to Contributors
Submit Article
Open Access
For Referees
Referee Guidelines
Review an Article
Annual Referee Index
For Advertisers
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with CP
blank image
facebook twitter youtube

 

Article << Previous     |     Next >>   Contents Vol 32(1)

Demography of feral camels in central Australia and its relevance to population control

A. R. Pople A C, S. R. McLeod B

A Biosecurity Queensland, Primary Industries and Fisheries, Department of Employment, Economic Development and Innovation, Alan Fletcher Research Station, PO Box 36, Sherwood, Qld 4075, Australia.
B Vertebrate Pest Research Unit, New South Wales Department of Primary Industries, Forest Road, Orange, NSW 2800, Australia.
C Corresponding author. Email: Tony.Pople@deedi.qld.gov.au
 
PDF (655 KB) $25
 Export Citation
 Print
  


Abstract

Since their release over 100 years ago, camels have spread across central Australia and increased in number. Increasingly, they are being seen as a pest, with observed impacts from overgrazing and damage to infrastructure such as fences. Irregular aerial surveys since 1983 and an interview-based survey in 1966 suggest that camels have been increasing at close to their maximum rate. A comparison of three models of population growth fitted to these, albeit limited, data suggests that the Northern Territory population has indeed been growing at an annual exponential rate of r = 0.074, or 8% per year, with little evidence of a density-dependent brake. A stage-structured model using life history data from a central Australian camel population suggests that this rate approximates the theoretical maximum. Elasticity analysis indicates that adult survival is by far the biggest influence on rate of increase and that a 9% reduction in survival from 96% is needed to stop the population growing. In contrast, at least 70% of mature females need to be sterilised to have a similar effect. In a benign environment, a population of large mammals such as camels is expected to grow exponentially until close to carrying capacity. This will frustrate control programs, because an ever-increasing number of animals will need to be removed for zero growth the longer that culling or harvesting effort is delayed. A population projection for 2008 suggests ~10 500 animals need to be harvested across the Northern Territory. Current harvests are well short of this. The ability of commercial harvesting to control camel populations in central Australia will depend on the value of animals, access to animals and the presence of alternative species to harvest when camels are at low density.

Keywords: fertility control, harvesting, population dynamics.


   
Subscriber Login
Username:
Password:  



    
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2014