Locomotory behaviour of a wild ground beetle is consistent within individuals and dependent on temperature and humidity

Locomotion is central to the lives of animals. Fluctuations in temperature and humidity can influence animal locomotion, particularly in ectotherms where internal and external temperatures are generally more closely coupled, despite the buffering effects of behavioural thermoregulation. The advances in radiotelemetry have permitted fine-scale movement data to be obtained under natural conditions on smaller animals. Despite their ubiquity, insect locomotion and its dependence on temperature and humidity have been little explored in the field. In this study, radiotelemetry was used to track 52 flightless ground beetles, Carabus hortensis , in a temperate forest in Northern Germany, recording 3870 beetle locations. The distances walked by beetles were dependent on temperature and relative humidity, with individuals moving farther at intermediate temperatures and extreme (high and low) humidities. Furthermore, individuals differed consistently in the distances they walked despite fluctuating temperature and humidity, showing that locomotion is a personality trait in this species under fluctuating field conditions. Results indicate that locomotory behaviour is a response to varying environmental conditions and a personality trait with potential implications on individual survival and reproductive success. • Locomotion is influenced by local abiotic environmental conditions. • We studied temperature and humidity impact on ground beetle locomotion in woodland. • A total of 52 Carabus hortensis were tracked every 2 h using radiotelemetry. • Distances walked were greatest at intermediate temperatures and humidity extremes. • Individuals differ consistently in distances walked, indicating personality.