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.

Woodhouse's scrub jays, like many other corvids, exploit ephemeral surpluses by storing food in scattered caches within their territories.

[5] 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.

[citation needed] 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.

Nests are built low in trees or bushes, 1–10 m (3.3–32.8 ft) above the ground, primarily by the female, while the male guards her efforts.

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.

Judging from mtDNA NADH dehydrogenase subunit 2 sequence data, there are two clades, namely a Pacific one west and one east of the Rocky Mountains.