The use of poison eggs for the control of stoats

Stoats (Mustela erminea) are an important predator of many forest bird spec ies in New Zealand, and more effective methods for their control are being sought. Stoat control using Fenn traps has been shown to prevent predation on mohua (Mohoua ochrocephala), but this technique is labour-intensive and costly to use for protection of large areas of habitat. We evaluated 1080 d elivered in eggs as a poison for control of stoats. The lethal dose has bee n determined by captive and field trials, but attempts to implement a large -scale control operation have given inconclusive results. To clarify the ef fectiveness of 1080 eggs as a control technique, we carried out further fie ld trials with radio-tagged stoats in the Makarora Valley. Twenty animals w ere monitored by radio tracking, and data loggers and video cameras recorde d their visits to bait stations. The precise time an individual stoat ate a poison egg could be determined from data logger and video information, and its fate was followed. Sixteen of twenty stoats were killed by 1080 eggs, three died of other causes and one remained alive at the end of the trials.