California Scrub-Jay

California Scrub-Jay

by Dave Zittin

California Scrub-Jays are noisy birds and their "weep" call is a common element of the local soundscape, especially in oak and scrub habitats.

California Scrub-Jays are bold and confident around humans. My first close encounter with the California Scrub-Jay occurred many years ago during lunch breaks when I worked in Palo Alto. When we ate outside, employees threw crumbs out to a “resident” California Scrub-Jay, and over time, I got the bird to come closer by reducing the toss distance. After a few weeks, I had the jay landing in my hand and feeding. The two of us saw eye-to-eye: he got food and I got really close looks. I later learned that hand-feeding can be detrimental to some species such as the friendly, but endangered Florida Scrub-Jay. Hand-feeding of this species can cause them to raise young too early in the season. Doing so can reduce the chances of supplying naturally available food during the growing period of the young. 

California Scrub-Jay with acorn. Steve Zamek

California Scrub-Jays are members of the New World genus Aphelocoma, of which there are seven species. The name translates to “simple hair” which reflects their feather colors that have no stripes or banding. California Scrub-Jays are a member of the family Corvidae, which also includes crows, ravens, magpies, and Clark’s Nutcracker. Frequently, people call the scrub jay a “blue jay”. This is incorrect because scrub jays are in a different genus than the Blue Jay, which is in the genus Cyanocitta. There are two species in this New World genus; the east coast Blue Jay and the Steller's Jay.

California Scrub-Jays are fairly common in my backyard, but they do not show up every day. They eat grain spread on the ground and when there is no feed on the ground, they eat suet from our hanging feeder. 

In nature, a primary food source for this species is acorns. California Scrub-Jays possess an outstanding ability to cache food and use spatial memory to find it later, much like their cousins, Clark’s Nutcracker. Of course, they don’t find it all, and there is some speculation that they are instrumental in facilitating the spread of various oak species. California Scrub-Jays also eats insects, reptiles, and small mammals. One time when driving near Loma Prieta Saddle we saw a California Scrub-Jay trying to kill a young rabbit in the middle of the road. Fortunately for the rabbit and to the detriment of the jay, I stopped, which kept the bird away until the bunny could make it across the road and into the brush while I got an earful from the jay.

California Scrub-Jay by Treasa Hovorka

California Scrub-Jays are aggressive and dangerous to smaller birds such as crowned sparrows, which keep a radius of a few yards when a jay is present.

Some jay species, for example, the Florida Scrub-Jay, are known for cooperative breeding, which is the rearing of young by individuals other than their parents. Western scrub jay species, including the California Scrub-Jay, do not demonstrate cooperative breeding.

The calls made by the California Scrub-Jay are varied, but a common call heard locally is a "weep" with an upswing in pitch.

California Scrub-Jays will vigorously mob bobcats, house cats, squirrels, owls, and anything else they think is a threat to them. The racket from this mobbing is noisy and can sometimes lead a birder to good views of a raptor such as an owl or a hawk.

California Scrub-Jays are excellent at recognizing and tossing the eggs of brood parasites (species that lay their eggs in the nests of non-related species) out of their nest. Researchers have experimentally added cowbird eggs to jay nests and observed they were tossed overboard in short order. This means that brood parasitism is virtually nonexistent for this species. 

Attracting California Scrub-Jays to Backyards

Spreading seed on the ground and suet feeders may draw California Scrub-Jays to your backyard. Sometimes they will also perch on our cylindrical, hanging seed feeder, but this is awkward for them and I don’t see this often.

Description

A medium-sized, crestless and long-tailed bird. Adults can be easily recognized by a gray-brown back with otherwise dull blue upper parts. The under parts are dull-whitish. Other features include dusky-colored ear coverts, a prominent whitish supercilium (eyebrow), and two bands of dark-bluish streaks extending onto the sides of the upper breast, almost forming a necklace. The beak, legs, and feet are black. The blue plumage tends to be duller blue in the Pacific Northwest, becoming darker and more purple towards southwestern California. Adults show no pronounced plumage differences between sexes. Juveniles have a lot of sooty gray color and lack the blue on top of their heads.

Scrub-Jay showing its gray back, blue wings and head, and conspicuous white eyebrow. Carter Gasiorowski

Distribution

California Scrub-Jays are a common year-round resident of the western coastal states, extending from Northern Washington to the tip of Southern Baja California. They are not migratory but tend to wander from their breeding range in the winter.

Similar Species

Nothing in our area looks like a California Scrub-Jay. Learning to tell their call from the Steller’s Jay takes a little practice. The flatter pitched call of Steller’s Jay often confuses beginning birders, but with a little experience, they are easy to tell apart.

Explore

  • Juvenile California Scrub-Jay

  • Typical “weep call” of California Scrub-Jay with pitch upswing

  • Flatter, screechier call of Steller’s Jay for comparison

More Backyard Bird Information

Banner Photo: California Scrub-Jay by Brooke Miller