Where have all the weta gone? Results after two decades of transferring a threatened New Zealand giant weta, Deinacrida mahoenui |
| |
Authors: | Corinne Watts Danny Thornburrow |
| |
Institution: | (1) Landcare Research, Private Bag 3127, Hamilton, New Zealand |
| |
Abstract: | There have been numerous transfers of the large-bodied orthopteran, the Mahoenui giant weta (Family Anostostomatidae: Deinacrida mahoenui), over the past 19 years but there has been limited follow-up monitoring to ascertain establishment and breeding of transferred
populations. Recent surveys carried out at all the locations where this weta were transferred, found weta at four of the seven
transferred sites. The most important factor determining the success of past transfers is the absence of introduced mammalian
predators, particularly rats, at a site. At two sites, Mahurangi Island Scenic Reserve and Warrenheip, weta appeared to be
flourishing and have successfully established new populations in the absence of rats. If mammals are present at a site, the
occurrence of dense prickly gorse to protect giant weta from predation is another important factor in their survival. Weta
were found at very low densities (only single specimens were captured) at Mangaokewa Scenic Reserve and Tikikaru (private
land) and it is likely their populations are not viable in the long term. Further efforts to establish Mahoenui giant weta
populations should be in mammal-free sanctuaries containing native forest. More intensive post-transfer monitoring using radio-transmitters
would enable better understanding of their behaviour after transfer. In addition, long-term regular monitoring of transferred
populations is required, particularly those where the likelihood of rat re-invasion is high. |
| |
Keywords: | Orthoptera Translocation Conservation Predation Rats Monitoring |
本文献已被 SpringerLink 等数据库收录! |
|