Proceedings of the Vertebrate Pest Conference

The kereru (New Zealand pigeon) is a threatened endemic species. Predation of eggs, chicks, and adults at nests by mammalian predators is considered to be a major potential threat. The impact of mammalian predators on kereru populations was studied on three remnant native bush areas on Banks Peninsula, New Zealand, from February 2004 to March 2005. In this study, 15 kereru were fitted with radio-transmitters and intensely monitored for survival. Three radio-tagged kereru were lost at the beginning of this study and their transmitters were redeployed, so a total of 18 radio-tagged kereru were monitored for predator-induced mortality. Five adult kereru died, 3 as a result of predation. A cat was recorded on video preying on one adult. It is hypothesised that cats were responsible for preying on other kereru during this study. Rat and possum predation limited nesting success; however, this could have been offset by replacement nesting after nest failures. Cats preyed on chicks and adult kereru, which impacted the breeding viability of the adult population. Kereru may be able to withstand some nest predation pressure if the pair is able to re-nest in the same season. However, the ability of kereru to re-nest is reliant on them having an adequate food source, so this may not be possible in poor seasons. These assertions require population modelling to determine their relative importance. Nesting success would benefit from rat and possum control during good breeding seasons. Adult survival would benefit from the control of predators such as cats and stoats. However, as kereru have integrated into urban habitat, managers must consult with the community before conducting predator control.