Impact of long-term behavioural studies in the wild: the blue petrel, Halobaena caerulea, case at Kerguelen

The study of animal behaviour contributes to our understanding of how individuals or populations live and survive. To this purpose researchers often manipulate, in a broad sense, wild animals in sensitive periods, such as breeding, when animals are accessible/available. Few studies, however, show the impact of these manipulations on the survival of individuals. In this study we measured short- and long-term impacts of experimental manipulations on a small colony of blue petrels at Kerguelen archipelago where behavioural studies have been performed since 2006. We developed two models to measure potential impacts of manipulation: (1) a new multievent model that allowed us to account for different severity classes of experimental manipulation independently and (2) a model that allowed us to consider the cumulative impact over several years of these experimental manipulations. We found no evidence that our experimental manipulations have negatively affected survival or breeding probabilities either in the short or in the long term. Conversely, similarly to other capture–recapture studies on blue petrels, survival was shown to be dependent on the birds' experience (birds that probably bred for the first time versus birds that had already bred several times before) and the breeding probability to be dependent on the year, possibly because of environmental conditions.