Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Reintroduction methods and a review of mortality in the brush-tailed rock-wallaby, Grampians National Park, Australia

Reintroduction methods and a review of mortality in the brush-tailed rock-wallaby, Grampians... Captive-bred brush-tailed rock-wallabies (BTRW) were reintroduced into the Grampians National Park, Australia, during 200812. Two release strategies (methods) were examined: Small release with supplementation (Strategy 1) and Larger release, no supplementation (Strategy 2).Of the 39 animals released, 18% survived. Thirty-six percent of all mortality occurred within the first 100 days. Under Strategy 1, 22 animals were released in five groups. Twenty deaths occurred across 48 months, with predation estimated to account for 15% of mortalities. Under Strategy 2, 17 individuals were reintroduced across one month. Twelve deaths occurred in the five months following release, with predation estimated to account for 83.4% of mortalities. Of the independent variables tested for their relationship to survival time after release, release strategy was the only significant predictor of survival time after release with the risk of death 3.2 times greater in Strategy 2.Independent variables tested for their relationship to predation risk indicated that release strategy was also the only significant predictor of predation risk, with the risk of death associated with predation 10.5 times greater in Strategy 2. Data suggested that fox predation was the main factor affecting BTRW establishment. Predation risk declined by 75% during the first six months after release. A significant positive relationship was also found between predation risk and colony supplementation events.We conclude that predation risk at Moora Moora Creek is reduced in releases of fewer animals, that it declines across time and that disturbing BTRW colonies through the introduction of new animals can increase predation risk. We recommend that future reintroductions should employ diverse exotic predator control measures at the landscape scale, time releases to periods of lowest predator activity, and limit colony disturbance to maintain group cohesion and social structure. Furthermore, the preferred method of population establishment should be single, small releases over multiple sites without supplementation. Further testing of the reintroduction biology of this species is urgently required. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Australian Journal of Zoology CSIRO Publishing

Reintroduction methods and a review of mortality in the brush-tailed rock-wallaby, Grampians National Park, Australia

Loading next page...
 
/lp/csiro-publishing/reintroduction-methods-and-a-review-of-mortality-in-the-brush-tailed-gTJ1lEsvAJ

References (65)

Publisher
CSIRO Publishing
Copyright
Copyright © The Author(s). Published by CSIRO Publishing
ISSN
0004-959X
eISSN
1446-5698
DOI
10.1071/ZO15029
Publisher site
See Article on Publisher Site

Abstract

Captive-bred brush-tailed rock-wallabies (BTRW) were reintroduced into the Grampians National Park, Australia, during 200812. Two release strategies (methods) were examined: Small release with supplementation (Strategy 1) and Larger release, no supplementation (Strategy 2).Of the 39 animals released, 18% survived. Thirty-six percent of all mortality occurred within the first 100 days. Under Strategy 1, 22 animals were released in five groups. Twenty deaths occurred across 48 months, with predation estimated to account for 15% of mortalities. Under Strategy 2, 17 individuals were reintroduced across one month. Twelve deaths occurred in the five months following release, with predation estimated to account for 83.4% of mortalities. Of the independent variables tested for their relationship to survival time after release, release strategy was the only significant predictor of survival time after release with the risk of death 3.2 times greater in Strategy 2.Independent variables tested for their relationship to predation risk indicated that release strategy was also the only significant predictor of predation risk, with the risk of death associated with predation 10.5 times greater in Strategy 2. Data suggested that fox predation was the main factor affecting BTRW establishment. Predation risk declined by 75% during the first six months after release. A significant positive relationship was also found between predation risk and colony supplementation events.We conclude that predation risk at Moora Moora Creek is reduced in releases of fewer animals, that it declines across time and that disturbing BTRW colonies through the introduction of new animals can increase predation risk. We recommend that future reintroductions should employ diverse exotic predator control measures at the landscape scale, time releases to periods of lowest predator activity, and limit colony disturbance to maintain group cohesion and social structure. Furthermore, the preferred method of population establishment should be single, small releases over multiple sites without supplementation. Further testing of the reintroduction biology of this species is urgently required.

Journal

Australian Journal of ZoologyCSIRO Publishing

Published: Jan 29, 2016

There are no references for this article.