The long-term impacts of an aerial 1080 application on non-target forest species [article]

Amanda Jane Peterson, University Of Canterbury
The control of introduced mammalian predators in New Zealand forests is crucial for the protection of native species and essential ecosystem services. Possum control in the form of aerial 1080 applications is conducted by TbFree New Zealand to prevent the spread of bovine tuberculosis, and often has the added conservation benefit of temporarily reducing levels of other mammalian predators such as rodents and mustelids. However, native non-target species such as birds and weta can also be at
more » ... of direct and secondary poisoning following 1080 applications, as well as increased predation risk through mesopredator release. To determine whether the benefits of 1080 applications outweigh the risks to non-target native species, both short and long-term monitoring of populations following aerial 1080 applications is needed. For this study, two forest regions in the South Island were selected for pre- and post-treatment monitoring of non-target species following an aerial 1080 application for possum control. Each region contained a treatment site and a paired non-treatment site. Relative indicies of possums, rodents and other mammalian predators were obtained using tracking tunnels and chew cards, indicies of birds were obtained using five-minute bird counts, and indicies of tree weta were obtained using tracking tunnels and artificial shelters. Monitoring was conducted before the aerial 1080 was applied in August 2012, and over the following 2012/13 and 2013/14 summer seasons. The aerial 1080 applications were successful at reducing possums to undetectable levels at both treatment sites for the two seasons following treatment. Mice were significantly reduced at one treatment site relative to the paired non-treatment site immediately following the 1080 operation, but had increased to pre-1080 levels by the second post-treatment monitoring season. Rats were detected at low levels, and showed no response to the treatment. Mustelids were not detected at either region throughout the monitoring period. No native species sho [...]
doi:10.26021/7222 fatcat:i43hxzd6hjh2jljqt2kbgmztma