Woodhouse's scrub jay (Aphelocoma woodhouseii), is a species of scrub jay native to western North America, ranging from southeastern Oregon and southern Idaho to central Mexico. Woodhouse's scrub jay was until recently considered the same species as the California scrub jay, and collectively called the western scrub jay. Prior to that both of them were also considered the same species as the island scrub jay and the Florida scrub jay; the taxon was then called simply the scrub jay. Woodhouse's scrub jay is nonmigratory and can be found in urban areas, where it can become tame and will come to bird feeders. While many refer to scrub jays as "blue jays", the blue jay is a different species of bird entirely. Woodhouse's scrub jay is named for the American naturalist and explorer Samuel Washington Woodhouse.
Description
Woodhouse's scrub jay is a medium-sized bird, approximately in length (including its tail), with a wingspan, and about in weight. The species has a blue head, wings, and tail; a gray-brown back; and grayish underparts. The throat is whitish with a partial blue breast band ("necklace"). The call is described as "harsh and scratchy". Compared to the California scrub jay, Woodhouse's has a duller blue, darker gray underparts, a less distinct blue necklace, and a straighter bill.
Habitat
True to its name, Woodhouse's scrub jay inhabits areas of low scrub, preferring pinon-juniper forests, oak woods, edges of mixed evergreen forests, and sometimes mesquite bosques. Woodhouse's scrub jays are very common west of the southern Rocky Mountains, and can be found in scrub-brush, boreal forests, and temperate forests.
Foraging
Woodhouse's scrub jays usually forage in pairs, family groups, or small non-kin groups, outside of the breeding season. They feed on small animals, such as frogs and lizards, eggs and young of other birds, insects, and (particularly in winter) grains, nuts, and berries. They can be aggressive towards other birds, for example, they have been known to steal hoarded acorns from Acorn Woodpecker granary trees.
Food storing
Woodhouse's scrub jays, like many other corvids, exploit ephemeral surpluses by storing food in scattered caches within their territories. They rely on highly accurate and complex memories to recover the hidden caches, often after long periods of time. In the process of collecting and storing this food, they have shown an ability to plan ahead in choosing cache sites to provide adequate food volume and variety for the future. Woodhouse's scrub jays are also able to rely on their accurate observational spatial memories to steal food from caches made by conspecifics. To protect their caches from potential 'pilferers', food storing birds implement a number of strategies to reduce this risk of theft. Western scrub jays are also known for hoarding and burying brightly colored objects. Woodhouse's scrub jays have a mischievous streak, and they are not above outright theft. They have been caught stealing acorns from acorn woodpecker caches and robbing seeds and pine cones from Clark's nutcrackers. Some scrub jays steal acorns they have watched other jays hide. When these birds go to hide their own acorns, they check first that no other jays are watching. Western scrub jays sometimes land on the backs of mule deer to eat ticks and other parasites present on the deer. The deer seem to appreciate the help, often standing still and holding up their ears to give the jays access. The scrub jay even will eat peanuts off a human hand.
Intelligence
Recent research has suggested that Woodhouse's scrub jays, along with several other corvids, are among the most intelligent of animals. The brain-to-body mass ratio of adult scrub jays rivals that of chimpanzees and cetaceans, and is dwarfed only by that of humans. Scrub jays are also the only non-primate or non-dolphin shown to plan ahead for the future, which was previously thought of as a uniquely human trait. Other studies have shown that they can remember locations of over 200 food caches, as well as the food item in each cache and its rate of decay. To protect their caches from pilfering conspecifics, scrub-jays will choose locations out-of-sight of their competitors, or re-cache caches once they are alone, suggesting that they can take into account the perspective of others.