Melanerpes uropygialis

Breeds throughout arid regions of southwestern U.S. and northwestern Mexico in arid lowland scrub, arid montane scrub, tropical deciduous forest, gallery forest, second-growth scrub, and secondary forest. Frequents deserts that have large cacti or trees suitable for nesting, dry subtropical forests, riparian woodlands, and plantations. Found in river bottoms with mesquite or cottonwood groves and dry washes (Baicich and Harrison 1997, Edwards and Schnell 2000, AOU 1998). From sea level to 1,000 m, occasionally to >1,600 m, higher in Aquascalientes (Selander and Giller 1963). In the few areas where it meets Golden-fronted Woodpecker (M. AURIFRONS), it seems to prefer drier, more desert-like habitats, whereas the Golden-fronted favors riparian woods (Selander and Giller 1963). Cover vegetation may be a significant habitat requirement. Cottonwoods and other desert riparian trees, and date palms supply cover in California. Saguaros are important habitat elements outside of California, but are scarce within the state and are not so important. Areas with parasitic berry-bearing mistletoe (PHORADENDRON SP.), particularly when on mesquite, are favored. (Edwards and Schnell 2000).

In California, found in riparian woodlands, cottonwood groves, parklands and residential neighborhoods that have tall trees all year round. Also found in orchard-vineyard and urban habitats, particularly in shade trees and date palm groves. In otherwise suitable areas in se. California, availability of excavatable tree trunks for nesting seems to be the primary factor determining presence of this woodpecker (Grinnell and Miller 1944).

In Arizona, found in desert habitats, especially with saguaro and other large cacti, semidesert, riparian woodland (cottonwood-willow, mesquite) and towns, in arid regions (Tropical and lower Subtropical zones) (AOU 1998). Density is positively correlated with the number of large saguaro cacti and negatively correlated with the slope of the area. Inhabits cottonwood-dominated habitat along lower Colorado River in winter and summer; almost absent in summer from areas dominated by screwbean mesquite (PROSOPIS PUBESCENS) and from areas without snags (Brush et al. 1983). Gila Woodpeckers did not occur in isolated cottonwood groves of less than 50 ac (20ha) in Arizona (Rosenberg et al. 1991).

In New Mexico, confined to lower elevation woodlands, especially those dominated by mature cottonwoods and/or sycamores, along stream courses (Hubbard 1987). In NE Baja California, found along streams in cottonwoods (POPULUS DELTOIDES) and willows (SALIX SP.) at Rancho Rosarito and sparingly at El Palmarito in scattered palms along an arroyo (Short and Banks 1965). However, also found in two Baja California localities without saguaro where likely nesting in desert fan palms (ERYTHEA ARMATA, Cornett 1986).

Holes produced by this woodpecker provide quarters many other bird species, mammals and reptiles, which also compete with it for nest sites (Winkler et al. 1995). Nesting cavities are utilized by American Kestrel, Elf Owl, Ferruginous Pygmy-Owl, Western Screech-Owl, Brown-crested Flycatcher, Purple Martin, Cactus Wren, lizards, snakes, rats, mice, etc. In Arizona, European Starling has had negative impact on Gila Woodpecker due to saguaro nest site competition, especially in area near agriculture and large lawns (Kerpez and Smith 1990b).

Declines in Gila Woodpecker numbers could have a negative impact on the entire bird and wildlife community that nests in saguaro cacti. Also, declines might directly affect survival of the saguaro itself because the woodpeckers may be important pollinators of the cacti (Edwards and Schnell 2000)

Apparently a monogamous and solitary breeder. Highly defensive against all avian intruders (Gillman 1915), particularly Gilded Flickers and European Starlings with which it competes for nest cavities (Erlich et al. 1988). Breeding season from April through July, with peak activity in April and May, usually ending in June-August.

Digs nest cavity in saguaro cactus (CARNEGIEA GIGANTIA) and Cordon (PACHYCEREUS PRINGLEI) cacti (Robbins et al. 1983), and to a lesser extent in cottonwoods (POPULUS), and willow (SALIX) (Bent 1939). Along the lower Colorado River, some nests found in honey mesquite (PROSOPIS GLANDULOSA) or screwbean (P. PUBESCENS; Anderson et al. 1982). Rarely nests in oaks and paloverde (CERCIDIUM SP.; Bent 1939), and in blue fan palm (ERYTHEA ARMATA) in one northern Baja California at locality without large cacti (Cornett 1986). In southern Arizona, Kerpez and Smith (1990a) report the greatest number of nests found in saguaro cacti in arroyos, where Gila Woodpeckers forage; fewer nests found in cacti on hillsides, ridgetops, or desert flats.

Does not nest in saguaros less than 4 (Karol and Hutto 1984) or 5 m tall in southern Arizona (Kerpez and Smith 1990a). Saguaro used for nesting are taller and more likely to have branches than randomly chosen saguaros. Nests rarely excavated above about 7 m (Karol and Hutto 1984, Smith 1990b), but rarely as low as 1 m (Edwards and Schnell 2000)

Nest hole excavated by both sexes in a living cactus or dead tree. Holes in living cacti can be used only after they have dried out. (Winkler et al. 1995), typically several months. May occupy the same nesting hole for more than one season until it is appropriated by an owl, kestrel, snake or large lizard. Non-randomly place nest holes on saguaro cacti in order to regulate its internal temperature. In cooler environments nest holes are often on the south-facing side, whereas on hotter environments the nest is placed on the north-facing side (Karol and Hutto 1984, Inouye et al. 1981). Nest holes are frequently excavated in live cactus after the nesting season to facilitate their drying.

Clutch size is three to five (Short 1982), rarely six eggs, with fewer eggs in second clutch (Bent 1939). Incubation poorly studied but reported to be 13 -14 days (Baicich and Harrison 1997). Both sexes incubate. Both males and females feed young (Edwards and Schnell 2000). Young leave nest about four weeks of age and are fed by adults for an extended period of time. Family grounds may remain together while adults renest. (Edwards and Schnell 2000). Can fly at approx. one month and in most cases a second brood fledges by late June. Family groups stay in territory after nesting until the young disperse or are driven away prior to the next breeding attempt.(Winkler et al. 1995). Sometimes 2-3 broods if food is abundant (Baicich and Harrison 1997). Brood parasitism not known to occur in this species.