THE INFLUENCE OF MOVEMENT AND RESTING BEHAVIOR ON THE RANGE OF THREE CARABID BEETLES

The need to study movement in specific ecosystems in order to understand population dynamics in space is appreciated among ecologists. Ecological data is, however, often collected at small scales making large‐scale predictions dubious at best. To examine whether extrapolations across scales are possible, we build observed behaviors affecting movement of three carabid beetle species, Pterostichus cupreus, P. melanarius and P. niger (Coleoptera, Carabidae), into a spatially explicit individual‐based model (IBM) to study patterns at a number of spatial scales. Field‐tracking recordings of individual beetles are fitted to a biased random walk (BRW) model and inserted into the IBM together with data on settling behavior. Beetles will often stop and rest during their activity periods. A range of probabilities for alternation between active and resting behavior are tested in the model at several prey levels. We found that at large scales, in this case movement over hundreds of meters and several seasons, diffusion is a good approximation for population spread. At small scales of around one meter, BRW describes movement accurately. At intermediate scales we need both BRW, resting, and changes between these behaviors to describe motion effectively in the model. The area covered by the beetles increases linearly over time, while the maximum distance moved does not, indicating an approximately circular expansion and a thorough search of area traversed. Seasonal range and estimated rate of movement differed among species depending on prey availability but was not correlated to body size.