Dendroica nigrescens

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Breeding

Global Range: BREEDING: southwestern British Columbia, western Washington, central Oregon, southwestern Idaho, northern Utah, southwestern Wyoming, northwestern and central Colorado, south in mountains to Arizona, eastern and southern New Mexico, northern Baja California, and northeastern Sonora, Mexico (AOU 1983, Guzy and Lowther 1997). Centers of abundance based on BBS data are in eastern Utah, southeastern Arizona, the Sierra Nevada, northwestern California, western Oregon, western Washington, and southwestern British Columbia (Sauer et al. 1997). NON-BREEDING: primarily in Baja California Sur and Pacific Slope and interior of Snora, Durango, Zacatecas, and Coahuila south to central Oaxaca. In small numbers in California and along Gulf Coast of U.S. (Guzy and Lowther 1997).

Length: 13 cm

Weight: 9 grams

Comments: BREEDING: Breeds in a variety of semi-arid woodlands; dry, open forests; mixed, moist forests; brushlands; chaparral. Especially uses conifers, live oaks, and mixed pinyon-juniper woodlands (Dunn and Garrett 1997). Inhabits juniper-pinyon-oak scrub on slopes, foothills, and canyons, where (in Wyoming) it is strongly associated with the presence of pinyon pine and high seedling/sapling density and understory height (Pavlacky and Anderson 2001). Also inhabits fir forests and edges of clearings. Nests in trees or shrubs 1-10 meters above ground, sometimes up to 15 meters (Harrison 1978; M. Guzy, pers. comm.). An early observer noted that the species likes well-scattered conifers; prefers high and dry places; and does not mind marsh or river nearby if ground beneath the nest is dry (Bowles 1902).

Generally uses younger age classes in northwest forests. In Douglas-fir forests in western Washington and Oregon, Meslow and Wright (1975) found the species nesting in shrub-sapling (7-15 years old), older second growth (41-120 years) and mature (> 120 years) successional communities, and using but not nesting in 16-40 year-old second growth. In Oregon Coast Range Douglas-fir forests, Carey et al. (1991) found highest densities in young stands (40-72 years; 9.06 birds per 40 hectares two-year average) in contrast to mature (80-120 years; 2.37 birds per 40 hectares two-year average) and old-growth stands (200-250 years; 3.04 birds per 40 hectares two-year average). Young stands typically had high densities of small-diameter trees (mean 269.7 stems per hectare of trees 10-19 centimeter dbh) and low densities of large trees over 50 centimeter dbh; also few large snags and low vertical foliage density. Similarly, in Douglas-fir forests of the Washington Cascades, were detected more frequently in young stands (55-80 years; mean 0.19 birds per visit) than in mature (95-190 years; 0.02 birds per visit) or old-growth stands (300-730 years; 0.06 birds per visit; Manuwal 1991). Young stands contained the highest mean densities (70 trees per hectares) of live trees less than 50 centimeter dbh and high densities (70 per hectare) of small snags less than 19 centimeter dbh. Huff and Raley (1991) also detected birds more often in young stands than in mature and old-growth stands in the Oregon Coast Ranges and Southern Washington Cascades, but in the Oregon Cascades they found little difference between stand age classes although the species was detected on a slightly greater percentage of old-growth stands.

On Vancouver Island, British Columbia, most often found in 50- to 60-year-old stands of mixed forests; an important elementis relatively open but brushy undergrowth (Campbell et al. 2001).

In southern Idaho, uses low ridges covered with open junipers (Burleigh 1972). In California, inhabits dry, open woodlands and brushy understories of foothills and mountains; breeds in ponderosa pine (PINUS PONDEROSA), valley-foothill hardwood-conifer, montane hardwood and pinyon-juniper habitats, and prefers oak woodland or pinyon-juniper mixed with chaparral or brushy understories (USDA Forest Service 1994). In northwestern Colorado pinyon-juniper habitat, prefers late-successional woodlands and occurs in similar woodland habitat to Plumbeous Vireo (VIREO PLUMBEOUS) and Dusky Flycatcher (EMPIDONAX OBERHOLSERI; Sedgwick 1987). In the Northwest, will use stands of regenerating deciduous trees and conifers in old clearcuts and burns (Dunn and Garrett 1997). In northern Arizona pinyon-juniper, observed to use and nest in juniper slightly more than other bird species (Balda 1969). In Mexico and northern Central America, breeds in semi-arid pine-oak and juniper woodland (Howell and Webb 1995). Breeds from 3,000 to 7,000 feet in the Sierra, up to 9,500 feet in White Mountains, California, but much lower in the Northwest (Dunn and Garrett 1997).

NON-BREEDING: In winter, uses arid mountain woodlands, including pine-oak. May use riparian habitats as travel corridors (USDA Forest Service 1994). In California, uses oaks and riparian willows and cottonwoods; in southwestern U.S., bottomland cottonwoods, willows, mesquite, and sycamores (Dunn and Garrett 1997). In Mexico and northern Central America, winters in arid to semi-humid oak and pine-oak forest and scrub (Howell and Webb 1995). In western Mexico, Hutto (1992) classified this species as a two-zone generalist that primarily uses tropical deciduous forest and thorn forest, and only 5 percent of observations were in pine-oak forest.

Systems

• Terrestrial

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Winters north of the Isthmus; from California lowlands and southern Arizona through western and central Mexico, from southern Baja, southern Sonora and Coahuila south to Oaxaca (Dunn and Garrett 1997).

Comments: Feeds mainly on insects (moths, butterflies, beetles, ants, etc.); may also eat leaf galls and a few spiders. Forages among leaves in bushes and trees. May forage high in trees or lower in trees and bushes. In southwestern Oregon and northwestern California use oak trees in spring for foraging on small green caterpillars (Bowles 1902).

Seen singly or in pairs; may be seen in small groups while migrating.

Clutch size is three to five (usually four). Incubation is done by female. Young are tended by both parents (Harrison 1978).

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 7 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 7
Specimens with Barcodes: 9
Species With Barcodes: 1

Canada

Rounded National Status Rank: N4B - Apparently Secure

United States

Rounded National Status Rank: N5B - Secure

Rounded Global Status Rank: G5 - Secure

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

Comments: May have a potentially high risk of local extinction due to a low frequency of occurrence, low abundance, long-distance migration, and loss of late-successional coniferous forests (Lehmkuhl and Ruggiero 1991). TIMBER HARVEST: Impacts of the broad range of timber harvest activities are mostly unknown. GRAZING: Grazing impacts largely unknown. Grazing in riparian vegetation along Sacramento River valley may threaten wintering populations in California (USDA Forest Service 1994), presumably by damaging or removing shrubs and saplings. PREDATION: Accipiters prey on adults; jays, crows and snakes prey on eggs and young (Guzy and Lowther 1997). BROOD PARASITISM: Considered a rare brown-headed cowbird (MOLOTHRUS ATER) host (Ehrlich et al. 1988), but little studied. Total of 20 records known; parasitism rates in very limited samples in California, Arizona, and New Mexico were 10 percent to 20 percent (see Guzy and Lowther 1997). In white Mountains, California, two nests were observed that had nest layers built over a cowbird egg, but no other antiparasitic responses have been recorded (Guzy and Lowther 1997).

Restoration Potential: This species uses a wide variety of woodlands and appears to respond positively to early successional stages of forest regeneration, so restoration potential would likely be high in a landscape of sustainable forest harvest or natural disturbance regimes. Sustaining riparian woodlands and chaparral habitats may be important to this warbler during migration and wintering. However much more detailed information is needed on the species biology to be conclusive about positive measures for restoration.

Preserve Selection and Design Considerations: May be area sensitive. Found to be positively associated with increasing stand area in Douglas-fir forests fragmented by timber harvest, however, no significant associations found with other measures of fragmentation (Rosenberg and Raphael 1986).

Management Requirements: Effects of management activities and disturbance are largely unstudied. Terborgh (1989) notes use of disturbed oak-woodland habitats on wintering grounds, but does not define type or extent of disturbance.

GRAZING: Effects of grazing activities are generally unknown. In pinyon-juniper, overstory removal to create pasture would be detrimental (Sedgwick 1987).

TIMBER HARVEST: Species is absent when forest overstory is removed. However, in an Engelmann spruce-subalpine fir forest, remained in interconnected forest remnants surrounding clearcuts four years after logging (8.30 singing males per 100 hectare; minimum width of residual stands was 413 +/- 59 meters) and occurred in similar densities to unlogged continuous forest (9.96 males per 100 hectares; Wetmore et al. 1985). The impacts of woodland fragmentation on productivity and survivorship are apparently unstudied. In pinyon-juniper habitats, tree removal may affect habitat use, as this warbler shows a preference for more mature trees in this habitat (Sedgwick 1987).

In northwestern Douglas-fir forests, however, shows a preference for younger stands, and densities are likely to be higher in young regenerating stands than in mature stands (Raphael et al. 1988, Carey et al. 1991, Huff and Raley 1991, Manuwal 1991). In the Oregon Coast Ranges, mean abundance was greater (P = 0.03) in unthinned stands than in stands commercially thinned five to fifteen years previous, where approximately 20 to 30 percent of the number of trees per hectare had been removed (Hagar et al. 1996). In even-age Douglas fir forests regenerating from clearcutting, Marcot (1985) found that mean densities were highest in shrub/sapling plots than in pole timber and medium sawtimber plots.

FIRE: Very little information available on relationship to burns. In a seasonal study of non-breeding bird abundances in ponderosa pine (PINUS PONDEROSA) forests on the Prescott National Forest, Arizona, Blake (1982) found the species restricted to unburned sites in fall and spring migration seasons.

Management Research Needs: Need detailed studies of response to habitat changes, including productivity and survivorship; monitoring of long-term changes in density in response to habitat alterations and succession; study of landscape and cumulative effects of habitat changes; rates of brood parasitism and behavioral response to parasitism. Information on migration and winter habitat use and ecology also needed.

Biological Research Needs: Nearly all aspects of the biology are poorly known. An excellent species for amateur and professional biologists to make significant contributions, especially as this warbler is relatively common and widespread and occupies a variety of woodland habitats. Studies are needed of behavior, breeding biology, wintering ecology, geographic variation in song, population dynamics, site fidelity, dispersal and migration.

Stewardship Overview: Has been little studied despite being widespread and relatively common in appropriate woodland habitats. Apparently prefers younger-aged successional stands of forest in the northwest, and in the short term, populations may be expected to increase in the region as the extensive harvest units of the 1970s and 1980s regenerate (Raphael et al. 1988, Spies et al. 1994). In pinyon-juniper habitats, however, shows a preference for mature trees and may be impacted by tree removal. Riparian areas, oak-woodlands, and chaparral are also important habitats. However, in western Douglas-fir forests are found in greatest abundance in young successional stands (Raphael et al. 1988, Carey et al. 1991, Huff and Raley 1991, Manuwal 1991). Much more information is needed to understand the species landscape relationships and ecology, particularly in response to habitat changes.

Species Impact: An insectivore that may be beneficial in reducing insect pests.