Holidays? Not for all. Eagles have larger home ranges on holidays as a consequence of human disturbance

Abstract

Human-wildlife conflicts are the object of raising concern in conservation biology. People living in urban areas are rapidly increasing worldwide and consequently the temporal pattern of occupation of natural areas for recreation is changing as well, resulting in an ever-increasing concentration of people during weekends and holidays. This is particularly evident in affluent societies, where more recreationists visit natural areas on holidays and weekends, causing disturbance to wildlife in the so-called “weekend effect”. Here, we tested the response to disturbance of 30 Bonelli's eagles tracked by high-frequency GPS/GSM telemetry. We analysed daily home-range size, a measure of changing behaviour that integrates their vital requirements, throughout the annual cycle, considering three different levels (95%, 75% and 50% kernel density estimators). Our results showed that eagles made a higher ranging effort on weekends and holidays throughout the annual cycle. This was particularly evident during the non-breeding period, when larger home-ranges were observed. Higher ranging effort can lead to conservation problems such as extra energy expenditure, hunting interference, and eventually nest and/or territory abandonment, decreasing eagles' fitness. Measures aimed at reducing human-wildlife conflicts including spatio-temporal limitation of leisure activities particularly during the most critical periods (i.e., incubation, chick rearing) are urgently needed. Finally, where possible, high quality information of animal movement should be incorporated into conservation plans in order to delineate efficient spatially-explicit management measures.