Wild kea response to non-toxic baits with and without deer repellent – implications for management

Abstract

ABSTRACT 1080 toxin (sodium fluoroacetate) is used in New Zealand for possum (Trichosurus vulpecula) and ship rat (Rattus rattus) control but can result in unintentional by-kill of native (e.g. kea Nestor notabilis) and non-native (e.g. deer) fauna. A newly developed deer repellent (Prodeer) in 1080 bait has proved highly effective in reducing deer by-kill while not impacting target pest efficacy. The ingredients in Prodeer bait are undisclosed due to commercial sensitivity, thus it is unknown whether this bait type increases acceptability and palatability to kea and increases risk over and above that posed by the standard (RS5) bait type normally used in aerial poisoning operations. During choice trials comparing kea responses to, and consumption of, non-toxic Prodeer and RS5 baits at alpine sites around Arthur’s Pass National Park and central Westland we found kea Prodeer and RS5 consumption (per interaction and total) were not significantly different. Most individuals consumed substantially less of both bait types than the estimated lower 1080 LD50 threshold for kea, and vastly less than captive kea consume. We conclude that 1080 operations using Prodeer are unlikely to pose a risk significantly over and above that already presented to kea in standard RS5 1080 operations.