Inconsistent fear: repeatability in flight initiation distance and neophobic behaviour differs in a ground-nesting bird

Flight initiation distance (FID), which refers to the distance at which a threat can approach an individual before it flees, is frequently used to investigate risk-taking behaviour, fearfulness and the responses of wildlife to predators and humans. Recent research has identified consistent between-individual variation in FIDs, indicating the emergence of shyer (risk-averse) and bolder (risk-prone) personalities and their potential to mediate differing life-history trade-offs. Given the disparate threats posed by anthropogenic global change, understanding animal behavioural responses to risks, particularly in wild populations, is becoming more important. However, relatively few studies have assessed the extent to which fearfulness in one context (e.g. humans via FIDs) generalizes across to fear in other contexts, such as fear of novelty (neophobia), thereby limiting our understanding of risk-averse strategies. We studied the relationship between the FID of incubating parents (boldness) and the time taken for parents to resume incubation in the presence of a novel object (neophobia) in a wild ground-nesting shorebird. We show that male and female FIDs varied in accordance with local nesting environment and that parents were repeatable in their FID responses, indicating significant between-individual differences in predator escape responses. However, neophobic responses were not repeatable and were unrelated to FIDs, which indicates that parents may not consistently conform to generally risk-prone or risk-averse behavioural syndromes and may not generalize fear responses across multiple potential dangers.