Food and vitamin D-3 availability affects lizard personalities: an experiment

摘要

It has been proposed recently that labile state variables (e.g. energy reserves) can have a key role in the development and maintenance of consistent between-individual behavioural variation (i.e. animal personality) within population. In male Carpetan rock lizards (Iberolacerta cyreni), the provitamin D-3 component of femoral gland secretion acts as an honest signal in sexual communication. Further, vitamin D-3 has many important metabolic functions in reptiles. Therefore, by employing a factorial experiment with food (high vs. low) and vitamin D-3 (supplemented vs. control) treatments in wild-caught reproductive male I. cyreni, we tested whether changing labile components of individual state affected (i) behavioural consistency (the degree of between-individual difference) and (ii) behavioural type (mean behaviour). Animal personality in activity was present in all treatments; however, personality was present only in the high food x vitamin D-3 supplementation treatment in shelter use and it was present in all but the low food x placebo treatment in risk taking. Lizards (i) decreased activity in the high food treatment, (ii) increased shelter use in the vitamin D-3 supplementation treatment and (iii) increased risk taking in the low food x vitamin D-3 supplementation treatment. We conclude that short-term changes in individual state affect both behavioural consistency and behavioural type of reproductive male I. cyreni. Unfavourable conditions resulted in decreased behavioural consistency, while high-state individuals became less active in general. Individuals with high specific (vitamin D-3) but low general (energy reserves) state took higher risk. We discuss several evolutionary explanations for the reported patterns.