The potential for eradication of hedgehogs (Erinaceus europaeus) from Quail Island, Banks Peninsula

Abstract

European hedgehogs (Erinaceus europaeus) are the most abundant mammal species remaining on Quail Island in Lyttelton Harbour. They are likely to be impacting on the existing native fauna of the island and will impede any future efforts to reintroduce native invertebrates, lizards and ground-nesting birds. During the summer of 1999/2000, Lincoln University researchers assessed the potential for eradication of hedgehogs from the island. Bait trials suggested that hedgehogs were readily live-trapped, that meat baits were more effective than eggs or cereal baits as lures, and that hedgehogs are present in all major habitat types on the island. A review of past studies suggested that a trap spacing of 150m should be suitable for hedgehog trapping. This spacing can be achieved on the 86 ha island by means of a grid of about 60 traps, which can be checked by one person in a day. Preliminary trapping with a grid of 53 live-traps over 11 nights resulted in the capture of 24 hedgehogs and 2 rats, with a time investment of 3.1 person hours per hedgehog captured. Catch rates did not decline significantly during the trial, which implies that a substantial population of hedgehogs remains on the island. It will take considerable additional effort to ensure that the last of these are captured.