Highly social pinyon jays, but not less social Clark’s nutcrackers, modify their food-storing behaviour when observed by a heterospecific

Behavioural flexibility can be described as the ability to use information and generalise it across contexts. Social living is thought to favour behavioural flexibility. We used a food-storing (caching) paradigm, during which individuals either ate or cached food under different conditions, to investigate whether they could flexibly adjust their caching behaviour when observed by conspecifics and heterospecifics. We examined the location and number of caches made by two corvid species differing in sociality, highly social pinyon jays (Gymnorhinus cyanocephalus) and less social Clark’s nutcrackers (Nucifraga columbiana). Although pinyon jays cached a similar amount of food across conditions, they allocated more caches to areas less accessible to the observer when the observer spent more time close to the caching locations. Nutcrackers, however, reduced the number of seeds cached when observed by another nutcracker in comparison to when they cached alone, but did not significantly change their caching behaviour when observed by a pinyon jay. The differences in cache protection strategies, and the social cues (e.g., presence and behaviour of an observing bird) that elicit them, may be explained by the species’ social organisation. Overall, our results provide insight into understanding how pressures associated with the social environment may influence foraging behaviours.

Behavior-specific occurrence patterns of Pinyon Jays (Gymnorhinus cyanocephalus) in three Great Basin study areas and significance for pinyon-juniper woodland management

The Pinyon Jay is a highly social, year-round inhabitant of pinyon-juniper and other coniferous woodlands in the western United States. Range-wide, Pinyon Jays have declined ~ 3–4% per year for at least the last half-century. Occurrence patterns and habitat use of Pinyon Jays have not been well characterized across much of the species’ range, and obtaining this information is necessary for better understanding the causes of ongoing declines and determining useful conservation strategies. Additionally, it is important to better understand if and how targeted removal of pinyon-juniper woodland, a common and widespread vegetation management practice, affects Pinyon Jays. The goal of this study was to identify the characteristics of areas used by Pinyon Jays for several critical life history components in the Great Basin, which is home to nearly half of the species’ global population, and to thereby facilitate the inclusion of Pinyon Jay conservation measures in the design of vegetation management projects. To accomplish this, we studied Pinyon Jays in three widely separated study areas using radio telemetry and direct observation and measured key attributes of their locations and a separate set of randomly-selected control sites using the U. S. Forest Service’s Forest Inventory Analysis protocol. Data visualizations, principle components analysis, and logistic regressions of the resulting data indicated that Pinyon Jays used a distinct subset of available pinyon-juniper woodland habitat, and further suggested that Pinyon Jays used different but overlapping habitats for seed caching, foraging, and nesting. Caching was concentrated in low-elevation, relatively flat areas with low tree cover; foraging occurred at slightly higher elevations with generally moderate but variable tree cover; and nesting was concentrated in slightly higher areas with high tree and vegetation cover. All three of these Pinyon Jay behavior types were highly concentrated within the lower-elevation band of pinyon-juniper woodland close to the woodland-shrubland ecotone. Woodland removal projects in the Great Basin are often concentrated in these same areas, so it is potentially important to incorporate conservation measures informed by Pinyon Jay occurrence patterns into existing woodland management paradigms, protocols, and practices.

Behavior-specific occupancy patterns of Pinyon Jays (Gymnorhinus cyanocephalus) in three Great Basin study areas and significance for pinyon-juniper woodland management

The Pinyon Jay is a highly-social, year-round inhabitant of pinyon-juniper woodlands in the western United States. Range-wide, Pinyon Jays have declined ~ 3 – 4% per year for at least the last half-century. At the same time, large acreages of pinyon-juniper woodland have been removed or thinned to improve habitat for Greater Sage-Grouse or other game species across much of the Great Basin, which is home to nearly half of the global population of Pinyon Jays. Occupancy patterns and habitat use of Pinyon Jays have not been well characterized across much of the species’ range, and obtaining this information is necessary for better understanding the causes of ongoing declines and determining useful conservation strategies. Our goal of this study was to identify the characteristics of areas used by Pinyon Jays for several critical life history components and to thereby facilitate the inclusion of Pinyon Jay conservation measures in the design of vegetation management projects. To accomplish this, we studied Pinyon Jays in three widely separated study areas using radio telemetry and direct observation, and measured key attributes of their locations and a separate set of randomly-selected control sites using the U. S. Forest Service’s Forest Inventory Analysis protocol. Data visualizations, non-metric dimension scaling ordinations, and logistic regressions of the resulting data indicated that Pinyon Jay occupancy was concentrated in a distinct subset of available pinyon-juniper woodland habitat, and further that Pinyon Jays used different habitats, arrayed along elevational and tree-cover gradients, for seed caching, foraging, and nesting. Caching was concentrated in low-elevation, relatively flat areas with low tree cover; foraging occurred at slightly higher elevations with moderate tree cover, and nesting was concentrated in somewhat higher areas with greater tree cover and higher stand density. All three of these Pinyon Jay behavior types were highly concentrated within the lower-elevation band of pinyon-juniper woodland close to the woodland-shrubland ecotone. Because woodland removal projects in the Great Basin are often concentrated in these same areas, it is critical to incorporate conservation measures informed by Pinyon Jay occupancy patterns into existing woodland management paradigms, protocols, and practices.

Mesotocin influences pinyon jay prosociality

Many species exhibit prosocial behaviour, in which one individual's actions benefit another individual, often without an immediate benefit to itself. The neuropeptide oxytocin is an important hormonal mechanism influencing prosociality in mammals, but it is unclear whether the avian homologue mesotocin plays a similar functional role in birds. Here, we experimentally tested prosociality in pinyon jays ( Gymnorhinus cyanocephalus ), a highly social corvid species that spontaneously shares food with others. First, we measured prosocial preferences in a prosocial choice task with two different pay-off distributions: Prosocial trials delivered food to both the subject and either an empty cage or a partner bird, whereas Altruism trials delivered food only to an empty cage or a partner bird (none to subject). In a second experiment, we examined whether administering mesotocin influenced prosocial preferences. Compared to choices in a control condition, we show that subjects voluntarily delivered food rewards to partners, but only when also receiving food for themselves (Prosocial trials), and administration of high levels of mesotocin increased these behaviours. Thus, in birds, mesotocin seems to play a similar functional role in facilitating prosocial behaviours as oxytocin does in mammals, suggesting an evolutionarily conserved hormonal mechanism for prosociality.