Data on female oviposition behaviour of the Pararge aegeria butterfly in outdoor cages (2019–2020)

We studied oviposition behavior in a butterfly (Pararge aegeria) that used to be confined to forest, but recently colonized anthropogenic areas too. This provides an ideal study system when trying to understand the underlying processes of niche expansion and colonisation success. The dataset produced allows us to test to what extent ecotype origin (agricultural vs. forest landscape types) and larval developmental conditions (open field vs. canopy-covered forest floors) affect multiple features of oviposition behahaviour. We also performed multiple behavioural trials per individual and considered changes in oviposition site preference within and over trials. The two provided files contain all behavioral or independent variables that were obtained during behavioural tracking of the oviposition behaviour of the Speckled Wood butterfly (Pararge aegeria) in an outdoor cage in 2019 and 2020. In the 'femdata' file, each line contains all dependent (e.g., proportion of time spent active) and ..., We caught females of either forest or agricultural ecotype and allowed their larval offspring to experience early-habitat cues in either open field or woodland conditions. Two times a week, grass pots were watered and checked for pupae. Pupae were collected, placed individually in plastic cups, and kept under standardized lab conditions (day/night: 23/16 °C; light/dark: 15/9 h) until adult emergence. Two to three days after adult emergence, one F1-female and three F1-males were introduced together into a small cage (0.3 x 0.3 x 0.3 m) for 24 h to ensure mating. Males and females that were allowed to mate came from different broods, but were of the same maternal ecotype. After mating, females were kept in the dark at lower temperatures (temperature day/night: 16/14 °C) in a Sanyo incubator. Adult females were tested in large outdoor cages. These cages (12 x 4.2 x 2.5 m) were located at forest edges, where host grass species of P. aegeria naturally occurred. From mid-September to mid-Octo...,