Between-population variation in homeward orientation behaviour in two riparian wolf spiders.

Animals make decisions based on various sources of information that differ in spatial and temporal scale of validity and/or applicability. This decision-making is expected to be shaped by evolutionary processes and is especially relevant in stressful situations. The importance of inherited sources of information or experience involved in orientation behaviour remains to date unclear. By means of a field-experiment, we evaluated variation in zonal recovery of two sympatric riparian Pardosa wolf spiders after releasing individuals offshore from a non-familiar river bank. After acclimatisation under controlled laboratory conditions, both species showed strong directional movements towards the natal river bank shore. Additionally, the more stenotopic riparian wolf spider showed considerable between-individual variation in orientation behaviour. In conclusion, information with respect to an individual's origin acts as an important cue for wolf spider orientation during movement. Our findings provide insights into decision-making processes in stressful situations and point to between-population variation in orientation behaviour, which relates to inherited factors and/or early-life (learned) experience.