Pinyon Jay (Gymnorhinus cyanocephalus)

The pinyon jay's common name derives from its close association with the pinyon pine, a collective name for a number of pine species bearing cones that produce edible seeds (2). In late August, when the pinyon seeds begin to ripen, the jays start foraging, skilfully extracting the seeds using their long, pointed beaks. Having bare nostrils allows the jays to probe deep into the pine cone using the entire length of their bill, avoiding the problem of feathers becoming fouled by the sticky pine-resin exuded by the cone. Once the cones fully mature and the seeds become exposed, the pinyon jays commence their amazing, food-caching behaviour. After evaluating whether the seeds are good, they break the seed coat open by pounding it with their bill and then swallow the kernel. Storing about four to five of these seeds in their expandable oesophagus, the jays then fly to a communal cache site, usually between one and five kilometres away from the main colony, where they bury the seeds in loose soil. Studies of pinyon jays in New Mexico found that a group of 250 birds managed to cache an incredible four and a half million seeds in one season (4). Using their phenomenal spatial memories, the birds are able to find many of these subterranean seed stores again, even under a covering of snow, which supply them with the nutrition and energy to be able to start their breeding season in the winter (3). The pinyon jay is normally found in large, loose communal flocks of around 250 birds, with a distinct social hierarchy, and form extensive nesting colonies during the breeding season (3). Breeding pairs are established following courtship around November and generally remain together for life (6). Both sexes in the pair work to create a fairly bulky, well-insulated nest from twigs, shredded grass and other available materials (2) (7). Three to four eggs are laid and incubated by the female, while the male joins a feeding flock, returning regularly to supply the female with food (7). After about 16 days the eggs hatch, and for the first ten days the nestlings are brooded by the female, until capable of maintaining their body temperature (6). After this time, the young gather into communal crèches of hundreds of individuals, where they continue to be fed by both parent birds. Such behaviour may serve as an anti-predator mechanism, since it allows for continual guarding of the nest by adults, while the others forage. The pinyon jay is relatively long-lived with adults reaching up to 16 years in the wild (2).

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