Acorn Woodpecker; Photo courtesy of Tom Greer © 2004 Tom Greer.Woodpeckers (Picidae Family)

Quail Ridge hosts six resident and two wintering species of woodpeckers. Most are characterized by bold dark and white patterns and red head or facial markings (more often on the male). The first indication of their presence is usually the loud, species-specific calls and tapping. Zygodactylous (two toes pointed forward and two behind) feet and stiff tail feathers facilitate climbing of tree trunks. All species use a strong, chisel-like bill to drum mating calls or territory delineations and to bore holes in trees for forage or nest cavities. Eggs are laid on the bare or chip-lined floor of the cavity, and both parents care for their young. The woodpecker diet consists predominantly of wood-associated insects found within tree canopies or caught aerially. Notable exceptions includes the Sapsuckers (Sphyrapicus sp.), which specialize on tree sap and the ants that it attracts, and the Acorn Woodpecker (Melanerpes formicivorus), which not surprisingly consumes acorns as a significant portion of its diet.

Red-breasted Sapsucker; Courtesy of Kim Cabrera © 2004 Kim CabreraContributing to their coexistence at Quail Ridge, each woodpecker species exhibits distinguishing patterns of behavior and habitat use. While most woodpeckers are solitary and monogamous, the highly social Acorn Woodpecker lives communally and participates in cooperative breeding and resource defense. Members of the colony store acorns and other food items in oak woodland “granaries” – trunks or telephone poles bored with holes – that they mutually defend. Although difficult for kleptoparasites to access, many of these nuts are supplementary resources for other species during winter. Another dietary specialist, the Red-breasted Sapsucker (Sphyrapicus ruber), provides rows of open sap wells and insects for other species; rows of sapsucker holes can be found in several trees on the bottom of Decker Canyon. A general forest inhabitant, the Northern Flicker (Colaptes auratus), is ubiquitous throughout California and the western U.S. The flicker frequents open ground for foraging and will nest in snags or any suitable cavities. Nuttall’s Woodpecker (Picoides nuttallii) is another common and endemic resident of California. It is the most prevalent woodpecker at Quail Ridge (density measured at nearly 2 birds/ha) and prefers nesting in dead riparian deciduous trees and foraging in oaks. Nuttall’s occasionally hybridizes with the Downy Woodpecker.

Sharing a similar range and physical appearance with the Hairy Woodpecker (Picoides villosus), the Downy Woodpecker (Picoides pubescens) frequents riparian and deciduous woodland as well as nearby grassy areas. While the Hairy forages on lower trunks of mature trees, the smaller Downy forages more peripherally on small tree limbs or weed stalks. Thus the Hairy more often resides in mature woods. Both species are uncommon on the Reserve.Pileated Woodpecker; Photo courtesy of Don Getty © 2004 Don Getty

Of special mention are the two resident pairs of Pileated Woodpecker (Dryocopus pileatus) at Quail Ridge. Although common to deciduous and mixed-coniferous forests of the eastern United States, the species has declined in the west with the loss of old-growth trees in which they nest. Sizeable nesting cavities and ample forest tracts are necessary to accommodate this large woodpecker. At Quail Ridge, these birds nest in either mature black oak or gray pine, maintaining year-round pair bonds and territories. This population is among the southernmost found breeding in the state in the Coast range.

Species and Guild Accounts

Birds Page

Listen and identify birds at: http://identify.whatbird.com/mwg/_/0/attrs.aspx

Photo Credits: Title, California Quail (Joyce Gross), Acorn Woodpecker (Tom Greer), Red-breasted Sapsucker (Kim Cabrera), Pileated Woodpecker (Don Getty; http://www.dongettyphoto.com/). For more pictures see: http://elib.cs.berkeley.edu/photos/fauna/

This page last updated: April 5, 2007  


Contact: Dr. Virginia Boucher
John Muir Institute of the Environment
109 The Barn, University of California, Davis, CA 95616
Phone: 530-752-6949; email: vlboucher@ucdavis.edu

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