Home‐range size and habitat use of European Nightjars Caprimulgus europaeus nesting in a complex plantation‐forest landscape

Abstract

In Europe, the consequences of commercial plantation management for birds of conservation concern are poorly understood. The European Nightjar Caprimulgus europaeus is a species of conservation concern across Europe due to population depletion through habitat loss. Pine plantation-forest is now a key Nightjar nesting habitat, particularly in northwestern Europe, and increased understanding of foraging habitat selection is required. We radiotracked 31 Nightjars in an extensive (185-km 2 ) complex conifer plantation landscape in 2009 and 2010. Home-range 95% kernels for females, paired males and unpaired males were an order of magnitude larger than song territories of paired males, emphasizing the importance of habitats beyond the song territory. Nightjars travelled a mean maximum distance of 747 m from the territory centre each night. Homerange placement relative to landscape composition was examined by compositional analysis. Pre-closure canopy forest (aged 5-10 years) was selected at all scales (MCP, 95% and 50% kernels), with newly planted forest (aged 0-4 years) also selected within 50% kernels. For telemetry fixes relative to habitat composition within 2 km of their territory centre, individuals again selected pre-closure and newly planted forest, and also grazed grass heath. Open ungrazed habitat was not selected, with implications for open habitat planning for biodiversity conservation within public-owned forests. Despite the Nightjars' selection for younger growth, moth biomass was greater in older forest stands, suggesting that foraging site selection reflects ease of prey capture rather than prey abundance. Within large plantation-forest landscapes, a variety of growth stages is important for this species and our results suggest that grazing of open habitats within and adjacent to forest will additionally benefit the European Nightjar.

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

“…Furthermore, home ranges were estimated following standard procedures. We did not follow standard radio telemetry triangulation methods as described by Sharps et al (), but instead drew observation bearings on a map in the field. Nevertheless, we are confident that this did not affect our conclusions, based on the mean tag error of 45 m and the reasoning outlined in the Supplementary material Appendix 3.…”

“…Whereas Sierro et al () studied nightjars in xeric deciduous shrubland with scattered coniferous trees, two other studies focussed on nightjars’ foraging ecology in coniferous plantations (Alexander and Cresswell , Sharps et al ). We calculated average maximal foraging distance of 2.6 ± 1.1 km, comparable to observed distances (3.1 ± 1.2 km) in Alexander and Cresswell ().…”

“…This map includes a detailed dataset of 2663 polygons describing approximately 740 habitat types. We reclassified this map into 29 relevant habitat types (Alexander and Cresswell , Sierro et al , Sharps et al ) (Table ). For each habitat type we calculated the percentage of available and used habitat using QGIS.…”

“…Conservation management for nightjars in Flanders is focused on the management of their breeding habitat (Louette et al ). However, studies in other parts of Europe showed activity patterns of nightjars to extend beyond their recognized breeding habitats (Alexander and Cresswell , Sierro et al , Sharps et al ). In those cases, nightjars were observed in meadows and grasslands (Alexander and Cresswell ), oak scrubland (Sierro et al ) and grazed grass heath (Sharps et al ).…”

“…However, studies in other parts of Europe showed activity patterns of nightjars to extend beyond their recognized breeding habitats (Alexander and Cresswell , Sierro et al , Sharps et al ). In those cases, nightjars were observed in meadows and grasslands (Alexander and Cresswell ), oak scrubland (Sierro et al ) and grazed grass heath (Sharps et al ). To assess the foraging ecology of nightjars in Flanders, we studied their spatial use in Bosland (northeastern Flanders) during a five‐year telemetry study.…”