Who's watching influences caching effort in wild Steller's jays (Cyanocitta stelleri).

Steller's jays (Cyanocitta stelleri) often store food and return to retrieve the stored items at a later time. Between caching and consumption, stored food has the potential to be pilfered by conspecific observers. We investigated whether individually marked Steller's jays in suburban neighborhoods of Arcata, California, USA, adjusted cache concealment effort when in the presence of conspecifics. Both male and female jays traveled the shortest distances to cache when alone, traveled further when a mate was present, and traveled furthest when neighbors from adjacent territories were present. These results suggest that Steller's jays recognize and respond to social contexts when concealing food items.

Steller sex: infidelity and sexual selection in a social Corvid (Cyanocitta stelleri).

Genetic analysis of avian mating systems has revealed that more than 70% of monogamous species show incidence of offspring parentage that does not match the social partner. Extra-pair parentage (EPP) has been linked to a variety of factors, including size and symmetry of ornamental traits, coloration, resource availability, and local conspecific density. We examined how ornamental plumage traits of individual Steller's jays (Cyanocitta stelleri) and territory characteristics influence genetic fidelity of socially monogamous pairs. We used seven highly polymorphic microsatellite markers to assign paternity to 79 offspring, and identified 12 (15.2%) as extra-pair young (EPY). Steller's jays with extra-pair young had significantly lower values of feather brightness and hue, indicating more ultraviolet-blue shifted coloration, and nested in closer proximity to the forest edge than Steller's jays with no detected EPY. Body size, crest height, asymmetry of ornamental crest stripes, as well as vegetative composition of territories and their proximity to supplemental feeders appeared to have little relationship to EPP. These results indicate that extra-pair parentage plays a role in the evolution of secondary sexual characteristics in both sexes, and suggest local density and availability of resources may influence Steller's jay mating dynamics.