Exploration-Avoidance and an Anthropogenic Toxin (Lead Pb) in a Wild Parrot (Kea: Nestor notabilis)
The ecological study of personality in animals is a relatively new field of behavioural investigation and of increasing importance to wildlife conservation. Kea (Nestor notabilis), hill country parrots endemic to South Island, New Zealand, are a good model for studying personality in an ecological context because they have a neophilic and explorative nature and are accessible for experimentation in the field. The study of personality is relevant to kea conservation if particular personality types (e.g., explorative) cause increased mortality, especially where kea come into contact with anthropogenic dangers. Its relevance may be even greater if, due to kea's social nature, social facilitation spreads that risk to other personality types. In this study I use experimental presentations of novel objects to investigate individual variation in exploration-avoidance behaviour in kea and apply my findings to the risk of lead exposure and poisoning because lead is present as novel objects in kea habitat. Analyses of blood lead levels and reactions to novel objects indicate that sex and age class, but more specifically personality, underlie a kea's reactions to novel objects and lead objects. Kea with explorative personalities have higher blood lead levels than aversive individuals. My results also indicate that social context, i.e., the presence of conspecifics and group size, are influential. Kea are more inclined to investigate novel objects in the presence of conspecifics, indicating that social facilitation plays a role in the exploration of novelty. Significant relationships between dominance category and behavioural response to novel objects indicates that social rank is related to personality, with dominant individuals being more explorative and subordinate individuals less explorative. These results highlight the potentially heavy cost of explorativity where kea and human habitats overlap. Explorative kea may be subject to an increased risk of injury or death and, if they facilitate exploration in aversive kea, increases the risk to those kea as well. Lead is a known cause of death in kea and as such affects kea survival. Lead has also been shown to have deleterious effects on other species at low levels.
Kea live in a highly seasonal and periodically severe environment, the dangers of which arecompounded by various anthropogenic hazards including lead exposure. Kea are a longlivedand slowreproducing species at a high risk of decline from even a small reduction in itssurvival rate an imposed reduction in numbers could result in nonrecovery.