The western scrub jay (Aphelocoma californica), is a species of
scrub jay native to western North America. It ranges from southern
Washington to central Texas and central Mexico.
It comprises three distinct subspecies groups, all of which may be separate
species. They are California scrub jay (coastal), Woodhouse's scrub
jay (interior US and northern Mexico), and Sumichrast's scrub jay
(interior southern Mexico). The western scrub jay was once lumped
with the island scrub jay and the Florida scrub jay; the taxon was
then called, simply, the scrub jay. The western 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. In recent years, the California scrub jay has expanded its
range north into the Puget Sound region of Washington.
The western scrub jay is a medium-sized bird, approximately 27?31 cm (11?12 in) in length (including its tail), with a 39 cm (15 in) wingspan, and about 80 g (2.8 oz) in weight. Coastal Pacific birds tend to be brighter in coloration than those of the interior, but all are patterned in blue, white and gray, though none as uniform in color as the related Mexican jay. In general, this species has a blue head, wings, and tail, a gray-brown back, and grayish underparts. The throat is whitish with a blue necklace. The call is described as "harsh and scratchy".
Western 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. Western 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
Recent research has suggested that western 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. Western scrub jays also summon others to screech over the body of a dead jay, according to new research from the University of California, Davis. The birds' cacophonous "funerals" can last for up to half an hour.
The nests are sturdy, with an outside diameter of 33?58 cm (13?23 in), constructed on a platform of twigs with moss and dry grasses lined with fine roots and hair. Four to six eggs are laid from March through July, with some regional variations. There are two common shell color variations: pale green with irregular, olive-colored spots or markings; and pale grayish-white to green with reddish-brown spots. The female incubates the eggs for about 16 days. The young leave the nest about 18 days after hatching.