Study on the foraging behaviour of the European nightjar Caprimulgus europaeus reveals the need for a change in conservation strategy in Belgium

Abstract

Effective nature conservation requires coherent actions based on the best available evidence concerning protected species. Recent studies have suggested that European nightjars Caprimulgus europaeus forage outside their recognized breeding habitats, yet, for Flanders (northern Belgium) information on nightjar foraging behaviour and key foraging habitats is lacking. To assess whether the foraging ecology of nightjars in Flanders is similar to that observed in other parts of Europe, we studied the crepuscular behaviour of this species in Bosland (northeastern Flanders) during a five-year radio telemetry study. Tracking of 48 individuals within a coniferous forest was standardized and home ranges were calculated using a kernel density estimator (fixed kernel). Habitat use was investigated by comparing kernel placement to available habitat. Average maximal foraging distance was 2603 +/- 1094 m and home ranges extended up to 691 ha. We identified the key foraging habitats to be extensively-cultivated grasslands and recreational areas, areas that were previously assumed unsuitable for Belgian nightjars. Our results indicate the importance of foraging sites outside the breeding territory, confirming the findings of previous studies performed elsewhere in Europe. Incorporating our findings into future conservation plans could, therefore, lead to improved efficiency of EU conservation measures, designed for the protection of this bird species in Flanders.