New Zealand Journal of Ecology (2003) 27(2): 139- 145

Observed responses of captive stoats (Mustela erminea) to nest boxes and metal collars used to protect kaka (Nestor meridionalis) nest cavities

Research Article
Terry C. Greene 1,*
Alan Jones 2
  1. Department of Conservation, Private Bag 4715, Christchurch, New Zealand
  2. Pureora Field Centre, Department of Conservation, R.D. 7, Te Kuiti, New Zealand
*  Corresponding author

Artificial barriers, such as nest boxes and metal collars, are sometimes used, with variable success, to exclude predators and/or competitors from tree nests of vulnerable bird species. This paper describes the observed response of captive stoats (Mustela erminea) to a nest box design and an aluminium sheet collar used to protect kaka (Nestor meridionalis) nest cavities. The nest box, a prototype for kaka, was manufactured from PVC pipe. Initial trials failed to exclude stoats until an overhanging roof was added. All subsequent trials successfully prevented access by stoats. Trials with a 590 mm wide aluminium collar were less successful, but this was mainly due to restrictions enforced by enclosure design: Stoats gained access above the collar via the enclosure walls and ceiling. In only one of twelve trials was a stoat able to climb past the collar itself. The conservation implications of these trials and directions for future research are discussed.