Habitat
Woodhouse's Scrub-Jays live primarily in pinyon-juniper and oak-pinyon forests of the interior western United States. Less often, you may find them in stands of mountain mahogany, juniper stands, among trees and cactus along desert streams, or in the oak scrublands of Texas's Edwards Plateau. In Mexico they also live in palmetto and thorn scrub in Oaxaca and in pine-spruce forests at high elevations in the Sierra San Pedro Mártir. They also live around people and may appear in suburbs, golf courses, and parks.Back to top
Food
Woodhouse's Scrub-Jays eat mostly insects and fruit during spring and summer, and switch to nuts and seeds during fall and winter. They eat small animals such as lizards and nestling birds, sometimes finding nests by following the parent birds. For plant material, Woodhouse's Scrub-Jays eat pine nuts, juniper berries, and grass seeds; sunflower seeds and peanuts at feeders; as well as cultivated corn, almonds, walnuts, and cherries. The birds aren't able to break pine cones before they open, but their relatively thin, straight, pointed bill helps them reach in and extract the rich pine nuts as soon as a gap opens.Back to top
Nesting
Nest Placement
Either male or female may choose the nest site. Typically fairly low (6-14 feet high) in a pinyon pine, serviceberry, or other small tree. Nests are often well hidden amid foliage and vines.
Nest Description
Scrub-jay nests are made of a basket of twigs lined with rootlets, fine strands of plant fibers, and livestock hair. Nests take about 12 days to build and are about 6 inches (15 centimeters) across when finished. Both members of a pair help with building.
Nesting Facts
| Clutch Size: | 1-5 eggs |
| Egg Length: | 0.9-1.3 in (2.4-3.4 cm) |
| Egg Width: | 0.8-0.8 in (1.9-2 cm) |
| Incubation Period: | 17-19 days |
| Nestling Period: | 17-19 days |
| Egg Description: | Pale green blotched with olive, or pale gray spotted with brown. |
| Condition at Hatching: | Naked and helpless, eyes closed. |
Behavior
Woodhouse's Scrub-Jays are animated birds that move about in bold hops and lunges, looking around with sharp turns of the head. Often found in flocks during winter, these birds are vocal and playful. Both members of a breeding pair staunchly defend their territory year-round, keeping other scrub-jays away by flying at them, calling, and occasionally pecking or grappling. Pairs stay together throughout the year and often feed each other, particularly during the breeding season. The female does all the incubation. In Oaxaca, Mexico, the subspecies known as "Sumichrast's" scrub-jay breeds cooperatively, with previously fledged birds remaining on their parents' territory and helping raise additional broods (similar to the Florida Scrub-Jay). During the nonbreeding season, flocks of birds that lack territories of their own (known as "floaters") form and may move away from breeding habitats. Nest predators include raccoons, weasels, skunks, squirrels, king snakes, gopher snakes, rattlesnakes, magpies, crows, and jays. Predators of adults and fledglings include bobcats, house cats, accipiters, and Great Horned Owls.Back to top
Conservation
Woodhouse's Scrub-Jays are common but populations in some regions show declines, according to the North American Breeding Bird Survey (notably in New Mexico, the Chihuahuan Desert, and the Sierra Madre of Mexico). Partners in Flight estimates the global breeding population for the "Western" Scrub-Jay (including Woodhouse's and California) at 2 million with 75% occurring in the U.S., 25% in Mexico, and less than 1% in Canada. "Western Scrub-Jay" is a U.S.-Canada Stewardship species, and rates a 9 out of 20 on the Continental Concern Score. The species is not on the 2016 State of North America's Birds' Watch List.Back to top
Credits
Gowen, F. C., J. M. Maley, C. Cicero, A. T. Peterson, B. C. Faircloth, T. C. Warr and J. E. McCormack. (2014). Speciation in Western Scrub-Jays, Haldane's rule, and genetic clines in secondary contact. BMC Evolutionary Biology 14:135.
Partners in Flight (2017). Avian Conservation Assessment Database. 2017.
Peterson, A. T. (1993). Adaptive geographical variation in bill shape of Scrub Jays (Aphelocoma coerulescens). American Naturalist 142:508–527.
Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2017). The North American Breeding Bird Survey, Results and Analysis 1966–2015. Version 2.07.2017. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.