Seasonal changes in activity and spatial and social relationships of the Iberian rock lizard, Lacerta monticola

Abstract

We conducted a field study to examine the significance of the seasonal changes in activity levels, spatial relationships, and social interactions of the Iberian rock lizard, Lacerta monticola, during the same favorable climatic period. Activity level, movement rate, home-range size, number of same-sex neighbors, and number of agonistic interactions decreased as the mating season finished for males but not for females. The number of females' home ranges overlapped by the home range of each male was also higher in the mating season than in the nonmating season. Measurements of available ambient temperatures showed that the thermal environment was suitable for the activity of lizards in both seasons, therefore the seasonal changes cannot be explained by thermal constraints. Males gain access to several females by increasing their home-range size, thus overlapping a larger number of females' home ranges, but as a consequence, also those of a larger number of male competitors. Thus, the cost of incurring agonistic interactions also increases. These results suggest that because activity and aggressiveness in males are related to their mating success, the balance between the costs and benefits of their activity and spatial strategies differs seasonally, and this may be the cause of the observed seasonal changes.