Density, social information, and space use in the common lizard (Lacerta vivipara)

Socially acquired information is widespread in the animal kingdom. Many individuals make behavioral decisions based on such social information. In particular, individuals may decide to leave or select their habitat based on social information. Few studies have investigated the role of density-related information, a potential social cue about habitat quality in dispersal. Here, we tested for the possibility that the phenotype of intruder common lizards (Lacerta vivipara) may inadvertently carry information about their natal population density. We found that such information use is likely. The behavior of focal lizard was influenced by the natal population density of the intruder it was interacting with. This suggests that individuals may use the behavior of others to acquire appropriate information about surroundings and to base spatial decisions on this information. Density-related information may then affect individual movement decisions and thus metapopulation dynamics.