Red-naped Sapsucker (Sphyrapicus nuchalis)
Associated Species: Other species that may use habitat in a similar way and/or respond similarly
to threats, management, and conservation activities include Violet-green Swallow, Purple Martin,
and Mountain Bluebird. Other species associated with mature aspen stands include Cooper's
Hawk, Broad-tailed Hummingbird, Western Wood-Pewee, Warbling Vireo, and House Wren.
Distribution: Red-naped Sapsuckers breed from southern British Columbia and Alberta south in
the Rocky Mountains to central Arizona and New Mexico, and from eastern Washington, Oregon
and California east to the Rocky Mountain front. In Colorado, they are fairly common breeders in
the foothills and lower mountains, especially aspen forests. They are rare spring and fall migrants
and very rare winters resident in the Four Corners area.
Habitat Requirements: Breeding habitat for Red-naped Sapsuckers in Colorado is aspen forests
or conifer forests mixed with aspen. They are most strongly associated with mature aspen
woodlands. Aspen and other hardwoods may be important for successful reproduction and
foraging, especially in close proximity to small openings and riparian zones with abundant
willows. They will preferentially nest in aspen, even when conifer snags are available.
Ecology: These sapsuckers arrive in breeding habitats by mid April and begin nesting in early
May. They raise only one brood each season. Their nests are placed almost exclusively in aspen
or other deciduous trees, and they construct new cavities each year, frequently in the same tree.
Nest trees are either green with heartrot, or dead. The abandoned nest cavities are important
nesting substrate for many secondary cavity nesters, and may be a critical habitat feature for some
bats. Their territory size is 2 to 5 ha (5-12 ac). In Colorado, nest trees average 23.3 cm (9.2 in)
dbh and 1 to 10 m (3-35 ft) in height. Orientation of nest cavities is generally southward. Their
diet consists of insects, tree sap from sap wells, and some fruit; they also hawk flying insects.
Management Issues and Conservation Recommendations: These birds respond well to partial
harvesting with small to moderate sized patch clear-cuts. Maintain at least 50% of management
areas in uncut patches. Retain aspen snags greater than 25.4 cm (10 in) dbh, especially near
riparian zones, water sources, and habitat edges. Snag densities in mature stands should exceed
15 per 4 ha (10 ac). Maintain disturbance regimes, natural and mechanical, and the dynamic
nature of aspen communities at the landscape scale. Where natural disturbance mechanisms
cannot be reintroduced, mechanical disturbance events should mimic, as closely as possible, the
disturbance history of the local area and surrounding habitats.
Decay-infected green trees are preferred for cavity construction and are often reused for several
consecutive seasons; individuals may show strong site fidelity. Maintain sufficient snag and live
cavity-tree densities within commercial harvest areas.
Status and Reasons for Concern: Population trends of this species are not adequately
monitored by the BBS in Colorado, but populations appear to be stable or slightly increasing at
the continental scale. Breeding densities of 5-10 pairs per 40 ha (100 ac), and 14 nests per 1.4
km2 have been reported. They were present on an average of 49.86% (SE = 4.44) of the BBS
routes run in Physiographic Area 62 in Colorado, 1988-1998, at an average abundance of
1.11(SE = 0.17) individuals per route. The mean number of routes run each year was 21.1 (SE =
3.06). This species is monitored by MCB with point transects.
Biological Objective: Maintain the species' distribution and abundance, based upon results of
the BBS and MCB monitoring programs.
Selected References: Andrews and Righter 1992, Baicich and Harrison 1997, Dobkin 1994,
Ehrlich et al. 1988, Kalcounis and Brigham 1998, Kingery 1998, Price et al. 1995, Yanishevsky
and Petring-Rupp 1998.