Gila Woodpecker Life History

Habitat

Gila Woodpeckers live in strictly arid environments, especially deserts and dry forests of the southwestern U.S. and adjacent Mexico, usually below elevations of 3,300 feet. The species is often most common in low swales and arroyos, including riparian corridors with cottonwood, willow, and mesquite. It is fairly tolerant of human development, so long as sufficient habitat for foraging and nesting remains. For nesting, many Gila Woodpecker pairs in Arizona utilize giant saguaro cactus, but in Mexico and southeastern California, they nest in many tree species as well.

Food

Gila Woodpeckers eat insects, small vertebrates, and berries. They peck, glean, and probe in cacti, trees, and shrubs. They forage primarily in dead vegetation, on trunk bark or large branches. Early and late in the day, they often forage higher in the vegetation and in the open, resting in the heat of the day or feeding in shaded interior vegetation. They are omnivorous, taking a wide range of insects, fruit, and small vertebrates, sometimes feeding on the ground for earthworms. They consume ants, beetles, aphids, scale insects, grasshoppers, cicadas, termites, moths, butterflies, and caterpillars. Foraging birds sometimes repeatedly tap when looking for food, listening for hollows with hidden prey, perhaps. They seldom drill or excavate large portions of dead trees as some woodpeckers do. When saguaro and other cactus fruits, mistletoe, or lycium berries are available, Gila Woodpeckers consume large quantities. Birds at feeding stations may eat corn, suet, and many types of fruit and nut, including pecans. Gila Woodpeckers sometimes steal eggs and nestlings from the nests of warblers, finches, and vireos.

Nesting

Nest Placement

Both male and female excavate the nest cavity, often in a tall saguaro cactus in a low area such as an arroyo rather than on a hill. Occasionally nests in oak, paloverde, mesquite, cottonwood, willow, or palm. The nest site is seldom more than 25 feet above the ground, and the average height is about 19 feet.

Nest Description

The nest chamber is unlined and varies greatly in its dimensions; an average might be about 6.8 inches wide by 11 inches deep. The entrance hole, often oval-shaped, is typically about 2 inches in diameter.

Nesting Facts

Behavior

Gila Woodpeckers begin to establish nesting territories in midwinter, when they excavate cavities. They defend an area about 50 yards in any direction from the nest cavity. They are among the most dominant bird species in the desert environments they inhabit. Males drive away other male Gila Woodpeckers and many other cavity-nesting bird species away from the territory. During winter, dominant males appear to take the most productive foraging territories, while females and subordinate males occupy less-productive areas. Males perform threat displays (pointing the bill, bobbing and shaking the head) before chasing and attacking other males, and they drive many other species of birds away from the territory as well.

Conservation

The North American Breeding Bird Survey estimates that in the U.S. portion of the species' range, where an estimated 28% of all Gila Woodpeckers live, populations have been roughly stable since 1968. However, a 2016 Partners in Flight report suggested the species has suffered a 44% decline overall since 1970. Partners in Flight estimates a global breeding population of 1.5 million birds and rates the species 11 out of 20 on the Continental Concern Score, indicating a species of low concern. Nevertheless, Partners in Flight estimates the species will lose another half of its population by 2068 if current rates of decline persist. Development of desert habitat that removes mature giant saguaros has caused some declines. The population increase in the invasive European Starling has reduced nesting success, as the aggressive starlings frequently evict Gila and other woodpeckers from their nest cavities.

Credits

Brenowitz, G. L. (1978b). Gila Woodpecker agonistic behavior. Auk 95:49-58.

Edwards, Holly H. and Gary D. Schnell. (2000). Gila Woodpecker (Melanerpes uropygialis), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Partners in Flight (2017). Avian Conservation Assessment Database. 2017.

Rosenberg, K. V., J. A. Kennedy, R. Dettmers, R. P. Ford, D. Reynolds, J. D. Alexander, C. J. Beardmore, P. J. Blancher, R. E. Bogart, G. S. Butcher, A. F. Camfield, A. Couturier, D. W. Demarest, W. E. Easton, J. J. Giocomo, R. H. Keller, A. E. Mini, A. O. Panjabi, D. N. Pashley, T. D. Rich, J. M Ruth, H. Stabins, J. Stanton, and T. Will (2016). Partners in Flight Landbird Conservation Plan: 2016 Revision of Canada and Continental United States. Partners in Flight Science Committee.

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.

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