Dispersal behaviour of female stag beetles (Lucanus cervus) in a mosaic landscape: when should I stay and where should I go

Global habitat destruction is bringing species to the edge. Consequently, understanding species dispersal behaviour is becoming essential in order to safeguard vital meta-populations. Nevertheless, dispersal is too often seen as unconditional rather than triggered by habitat cues. We applied radio telemetry on female European stag beetles [Lucanus cervus (L., 1758)] in a mosaic landscape to investigate the hypothesis that dispersal is habitat driven, in this case by canopy closure and presence of suitable dead wood, SDW. We found that the decision to disperse depended on canopy closure and that dispersal distance depended both on SDW availability and canopy closure. Long distance dispersal (by flying), in contrast to small distance dispersal (mainly walking), is shown to be a successful strategy to reach locations with lower canopy closure. We conclude that dispersal of female stag beetles is not unconditional but shaped by habitat resources. It is therefore likely that habitat also affects dispersal of other insects and should be considered in future dispersal studies. For the conservation of the European stag beetle, our results imply that it is essential to provide stepping stones of suitable dead wood, preferably every 100 m and not more than 1 km apart. These stepping stones should be provided in open to half-shaded conditions. Management systems such as coppicing which provide periodic sun-exposure and sufficient amounts of (underground) dead wood are good management procedures for conservation of the stag beetle but they need to be performed at small scales to ensure suitable habitat proximity.