Testing the independent effects of population and shelter density on behavioural and corticosterone responses of tree skinks

摘要: In animals, social organisation and behaviour can respond to variation in key ecological factors including population resource density. As these two covary, their relative importance is difficult estimate using field studies. Consequently, we conducted manipulative experiments varying levels of either or shelter density separate effects on solitary, affiliative agonistic physiology the tree skink, Egernia striolata. We used focal observations plasma concentrations hormone corticosterone measure behavioural physiological responses manipulations. Aggressive behaviours occurred more frequently at high skink density, with males exhibiting stress, as indicated by increased corticosterone. Skinks low densities showed greater behaviour, spending time basking pairs. Changes influenced exploratory behaviours, exploring enclosures than those densities. sheltered pairs even after taking into account differences frequency pair sheltering expected chance alone, suggesting that availability promotes behaviour. Corticosterone over which may have been a result thermal stress coupled lack microclimate comparison These results suggest are independently influence endocrinology, consequently organisation, different ways.