Cover Picture and Issue Information

This month’s cover image shows two male sleepy lizards ( Tiliqua rugosa ) fighting. Fights in these long‐lived lizards allow males to exclude others from their core home range and to follow their monogamous female partners throughout the breeding season. Since this species is the main host for some local ticks, it is also a suitable model system for studying the effects of host‐behaviour on parasite transmission. Identifying the ecological factors that shape the structure of lizards’ social networks is important both for understanding their biology and for disease ecology. Separating the contributions of ecological constraints and social preference is a general challenge in social networks studies (i.e. did two animals meet because they had to share a resource or because they were attracted to each other?). Spiegel et al. present a new method for analysing social networks and teasing apart these contributions. After validating their method with synthetic datasets obtained from computer simulations they use the lizards tracking dataset to explore these questions and demonstrate the utility of the method. They found that lizards show strong conspecific attraction, interacting more frequently and with more neighbours than expected by chance. Note, however, that these interactions are not necessarily friendly, as the two males in the picture remind us. Photo credit: © Dale Burzacott 2015