Understanding attacks by kea (Nestor notabilis), an endemic parrot, on sheep (Ovis aries) in the South Island high country : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University/Te Kunenga ki Pūrehuroa, Manawatū, Aotearoa New Zealand

Abstract

Human-wildlife conflict is a complex global issue that can have negative impacts on wildlife species and human livelihoods. An ongoing example of such conflict in Aotearoa New Zealand occurs between high country sheep farmers and kea (Nestor notabilis). This study is the first to document the conflict since attempts were made in the early 20th century. My aims were to: 1.) review the historical records of the conflict, and estimate the number of kea killed under a 100+ year bounty scheme; 2.) characterise sheep wounds attributed to kea attacks (‘kea strike’), and estimate the current prevalence and associated risk factors; 3.) survey high country farmers’ experiences with and perspectives of kea strike; 4.) examine behaviours that potentially underpin kea strike via experimental tasks presented to wild kea. I estimated that at least 116,869 kea were killed historically as a result of the bounty scheme. The majority of sheep wounds attributed to kea strike were in the loin (lumbar) region, and the wound prevalence was low (0–1.25%). However, it should be noted that the prevalence reported by farmers can be higher, and that higher kea strike frequency results in considerable economic and welfare costs for some high country sheep stations. Risk factors included station location, breed (Perendale), class (ram), and age (>1 yr). The results of an anonymous online survey of high country sheep farmers showed that less than half of the farmers reported kea strike, with low estimates of sheep injuries and losses, and a decrease of kea strike over the past 25+ years, which may have resulted from decreasing kea numbers and changes in sheep flock management. More than half of the farmers thought that only some kea attack sheep, which is consistent with the long-standing concept that kea strike is instigated by ‘rogue’ kea (problem individuals). Individual kea differed in innovative problem solving performance, exploration tendency and neophobia, and exploration tendency was linked with social rank and innovation. I propose that high ranking males that are innovative and exploratory may initiate kea strike. Understanding the drivers of kea strike can be used to inform conservation management decisions regarding farmer-kea conflict, to the benefit of kea, high country sheep farmers and their stock.