Hylocichla mustelina - (Gmelin, 1789)
Wood Thrush
Other English Common Names: wood thrush
Taxonomic Status: Accepted
Related ITIS Name(s): Hylocichla mustelina (J. F. Gmelin, 1789) (TSN 179777)
French Common Names: grive des bois
Spanish Common Names: Zorzal Maculado
Unique Identifier: ELEMENT_GLOBAL.2.106491
Element Code: ABPBJ19010
Informal Taxonomy: Animals, Vertebrates - Birds - Perching Birds
 
Kingdom Phylum Class Order Family Genus
Animalia Craniata Aves Passeriformes Turdidae Hylocichla
Genus Size: A - Monotypic genus
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Concept Reference
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Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Concept Reference Code: B98AOU01NAUS
Name Used in Concept Reference: Hylocichla mustelina
Taxonomic Comments: See Winker and Rappole (1988) for discussion of evidence indicating that the wood thrush does not warrant recognition as a genus (i.e., Hylocichla) separate from Catharus
Conservation Status
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NatureServe Status

Global Status: G4
Global Status Last Reviewed: 08Apr2016
Global Status Last Changed: 13Mar2014
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G4 - Apparently Secure
Reasons: Large range in eastern North America; many occurrences; long-term decreasing population trend (per BBS data) but still common in many areas; threatened by forest fragmentation and resulting increases in brood parasitism by cowbirds and nest predation.
Nation: United States
National Status: N5B (19Mar1997)
Nation: Canada
National Status: N4B,NUM (25Jan2018)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (S5B), Arkansas (S3B), Colorado (SNA), Connecticut (S4B), Delaware (S5B), District of Columbia (S3B,S4N), Florida (S4B), Georgia (S5), Illinois (S4), Indiana (S4B), Iowa (S4B,S4N), Kansas (S3B), Kentucky (S5B), Louisiana (S4B), Maine (S4B), Maryland (S5B), Massachusetts (S5B), Michigan (S4), Minnesota (SNRB), Mississippi (S5B), Missouri (S4), Nebraska (S3), New Hampshire (S5B), New Jersey (S3B), New York (S5B), North Carolina (S4B), North Dakota (SU), Ohio (S5), Oklahoma (S2B), Pennsylvania (S5B), Rhode Island (S5B), South Carolina (S3?B), South Dakota (S2B), Tennessee (S4), Texas (S4B), Vermont (S5B), Virginia (S5), West Virginia (S3B), Wisconsin (S4B), Wyoming (SNA)
Canada New Brunswick (S1S2B,S1S2M), Nova Scotia (SUB), Ontario (S4B), Quebec (S3S4)

Other Statuses

Canadian Species at Risk Act (SARA) Schedule 1/Annexe 1 Status: T (02Nov2017)
Committee on the Status of Endangered Wildlife in Canada (COSEWIC): Threatened (25Nov2012)
Comments on COSEWIC: Reason for designation: In Canada, this forest-nesting species has shown significant long and short-term declines in population abundance. The species is threatened by habitat loss on its wintering grounds and habitat fragmentation and degradation on its breeding grounds. It also suffers from high rates of nest predation and cowbird parasitism associated with habitat fragmentation on the breeding grounds.

Status history: Designated Threatened in November 2012.

IUCN Red List Category: LC - Least concern

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: BREEDING: southeastern North Dakota and central Minnesota across the northern U.S. and adjacent southern Canada to Nova Scotia; south to eastern Texas, the Gulf Coast, and northern Florida; and west to eastern South Dakota, central Nebraska, central Kansas, and eastern Oklahoma. Casual breeder to southern Manitoba, southwestern North Dakota, and central South Dakota (AOU 1983). NON-BREEDING: southern Texas south through eastern Mexico and Middle America to Panama and northwestern Colombia (AOU 1983).

Area of Occupancy: 2,501 to >12,500 4-km2 grid cells
Area of Occupancy Comments: Breeds throughout eastern North America from southern Canada to north Florida. Winters in portions of Mexico and Central America. With an estimated 11 million individuals, should easily meet minimal occupancy estimate.

Number of Occurrences: 81 to >300
Number of Occurrences Comments: Many occurrences, with Partners in Flight (2013) estimating 11 million individuals globally.

Population Size: >1,000,000 individuals
Population Size Comments: Based on Partners in Flight numbers (2013).

Number of Occurrences with Good Viability/Integrity: Many to very many (41 to >125)
Viability/Integrity Comments: Given recent declining trend, the number of "good" EOs is suspect but with several million individuals there should be at least 41 "good" EOs.

Overall Threat Impact Comments: Habitat degradation and fragmentation are commonly cited as the biggest threats. With loss of habitat and increased conversion to agriculture and pine plantations, both brood parasitism and nest predation increase. The Brown-headed Cowbird (MOLOTHRUS ATER) is by far the most serious threat, causing significant population declines throughout much of the range. Despite the fact that cowbirds are such a problem, control of cowbird numbers rarely has been attempted. Rate and impact of cowbird parasitism is highest in the Midwest, lowest in the Northeast (Hoover and Brittingham 1993). In forest fragments in northern Indiana, 90% of 278 nests contained an average of 2.4 cowbird eggs/parasitized nest; there was no relationship between size of forest fragment and cowbird parasitism but the entire landscape "appeared to be part of a regional sink for Wood Thrushes" (Fauth 2000). Data were collected from fragmented forests in Illinois by Robinson (1992), where thrushes also suffered extraordinarily high rates of brood parasitism. Of 19 nests found, all were parasitized with an average of 1.2 host eggs per nest, and an average of 4.6 cowbird eggs per parasitized nest; thrushes raised far more cowbirds than they did wood thrushes. Of 15 thrush nests found during the incubation period, only a single thrush fledgling was produced. One nest had 12 cowbird eggs in it. Similar results have been found for the Shawnee National Forest of southern Illinois, although parasitism rates are somewhat lower--89% of 83 nests contained an average 3.2 cowbird eggs per parasitized nest (Robinson and Wilcove 1994). On four separate occasions, Hoover (1992) witnessed common grackles (QUISCALUS QUISCULA) preying on all of the eggs in four different nests (blue jay [CYANOCITTA CRISTATA] and American crow [CORVUS BRACHYRHYNCHOS] were likely to be other avian nest predators). Brood parasitism by cowbirds was less prevalent in Hoover's (1992) study, 18% and 6% of all nests being parasitized in 1990 and 1991, respectively. Nest records for 896 nests (Cornell Laboratory of Ornithology) indicated that rates of brood parasitism differed significantly among the Midwest (42.1%), the mid-Atlantic (26.5%), and the Northeast (14.7%) regions of the U.S. Because of the high abundance of cowbirds, high percentages of nests parasitized, and high numbers of cowbird eggs per parasitized nest, the effects of cowbird parasitism are particularly detrimental to populations in the Midwest. Another possible threat includes loss of forest undergrowth due to overgrazing by high deer populations. On the other hand, dense herbaceous growth resulting from waste-water irrigation is detrimental (Rollfinke et al. 1990). Loss of tropical forests also may contribute significantly to regional declines in temperate North America.

Short-term Trend: Decline of 10-50%
Short-term Trend Comments: North American Breeding Bird Survey (BBS) data indicate a significant 2.20% annual decline occurred in North America from 2002 to 2012 (Sauer, et. al. 2014).

Long-term Trend: Decline of 30-70%
Long-term Trend Comments: North American Breeding Bird Survey (BBS) data indicate a significant 2.22% annual decline occurred in North America from 1966 to 2011 (Sauer, et. al. 2014).

Intrinsic Vulnerability: Moderately vulnerable
Intrinsic Vulnerability Comments: Especially subjected to brood parasitism by Brown-headed Cowbirds as habitat gets fragmented and cowbirds become more numerous (Evans, et. al. 2011).

Environmental Specificity: Moderate. Generalist or community with some key requirements scarce.
Environmental Specificity Comments: Utilizes primary and old second-growth forests on lower slopes in Central America. The exact relationship of habitat fragmentation with Wood Thrush population numbers is unclear and needs further research still (Evans, et. al. 2011).

Other NatureServe Conservation Status Information

Inventory Needs: Additional studies are needed in the tropics link age and sex-specific survival rates to population declines (Evans, et. al. 2011).

Protection Needs: Population stability requires protection of primary and old, secondary broad-leaved tropical forests on e. Caribbean slopes and of multiple replicates of temperate deciduous forests over entire geographic range, especially ones ò100 ha with few roadcuts. Also, connectivity and source-sink dynamics between forest fragments must be considered when evaluating the suitability of habitat for conservation purposes. This may be particularly important for juvenile dispersal (Evans, et. al. 2011). Control cow bird populations where Wood Thrushes nest to reduce brood parasitism (see G THREATS COMMENTS).

Distribution
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Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDING: southeastern North Dakota and central Minnesota across the northern U.S. and adjacent southern Canada to Nova Scotia; south to eastern Texas, the Gulf Coast, and northern Florida; and west to eastern South Dakota, central Nebraska, central Kansas, and eastern Oklahoma. Casual breeder to southern Manitoba, southwestern North Dakota, and central South Dakota (AOU 1983). NON-BREEDING: southern Texas south through eastern Mexico and Middle America to Panama and northwestern Colombia (AOU 1983).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
NOTE: The maps for birds represent the breeding status by state and province. In some jurisdictions, the subnational statuses for common species have not been assessed and the status is shown as not-assessed (SNR). In some jurisdictions, the subnational status refers to the status as a non-breeder; these errors will be corrected in future versions of these maps. A species is not shown in a jurisdiction if it is not known to breed in the jurisdiction or if it occurs only accidentally or casually in the jurisdiction. Thus, the species may occur in a jurisdiction as a seasonal non-breeding resident or as a migratory transient but this will not be indicated on these maps. See other maps on this web site that depict the Western Hemisphere ranges of these species at all seasons of the year.
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AL, AR, CO, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, ND, NE, NH, NJ, NY, OH, OK, PA, RI, SC, SD, TN, TX, VA, VT, WI, WV, WY
Canada NB, NS, ON, QC

Range Map
Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.natureserve.org/conservation-tools/data-maps-tools.

Range Map Compilers: NatureServe, 2002


U.S. Distribution by County Help
State County Name (FIPS Code)
NE Dixon (31051), Nemaha (31127), Richardson (31147)
NJ Atlantic (34001), Bergen (34003), Burlington (34005), Camden (34007), Cape May (34009), Cumberland (34011), Essex (34013), Gloucester (34015), Hunterdon (34019), Mercer (34021), Middlesex (34023), Monmouth (34025), Morris (34027), Ocean (34029), Passaic (34031), Salem (34033), Somerset (34035), Sussex (34037), Union (34039), Warren (34041)
SD Charles Mix (46023), Clay (46027), Corson (46031), Gregory (46053)*, Lincoln (46083), Minnehaha (46099), Roberts (46109)*
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
02 Rondout (02020007)+, Hackensack-Passaic (02030103)+, Sandy Hook-Staten Island (02030104)+, Raritan (02030105)+, Middle Delaware-Mongaup-Brodhead (02040104)+, Middle Delaware-Musconetcong (02040105)+, Crosswicks-Neshaminy (02040201)+, Lower Delaware (02040202)+, Cohansey-Maurice (02040206)+, Mullica-Toms (02040301)+, Great Egg Harbor (02040302)+
07 Upper Minnesota (07020001)+*
10 Upper Lake Oahe (10130102)+, Fort Randall Reservoir (10140101)+*, Ponca (10150001)+*, Lewis and Clark Lake (10170101)+, Lower Big Sioux (10170203)+, Tarkio-Wolf (10240005)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Basic Description: A 20-cm bird (thrush).
General Description: Length 20 cm. Sexes similar. Reddish-brown above, brightest on crown and nape; rump and tail brownish-olive. Bold white eye ring conspicuous on streaked face. Whitish below, with large dark spots on throat, breast, and sides.

VOCALIZATIONS: Loud, liquid song of three- to five-note phrases, most notes differing in pitch, each phrase usually ending with a complex trill. Calls include a rapid "pit pit pit" (NGS 1987).

NEST: firm, compact cup of grasses, bark, moss, paper, mixed with leaf mold, mud; molded by contours of female's body; lined with rootlets. Outside diameter 10.2-14 cm, height 5.1-14.6 cm; inside diameter 7 x 8.3 cm, depth 3.2-5.1 cm.

EGGS: average size 25.4 x 18.6 mm; typically oval; shell is smooth, has slight gloss; pale blue or bluish green and unmarked.

Diagnostic Characteristics: Smaller than American Robin (TURDUS MIGRATORIUS) and plumper than the other brown thrushes (Gray-cheeked Thrush [CATHARUS MINIMUS], Bicknell's Thrush [CATHARUS BICKNELLI], Swainson's Thrush [CATHARUS USTULATUS], Hermit Thrush [CATHARUS GUTTATUS], and Veery [CATHARUS FUSCESCENS]). Distinguished by the deepening redness about the head and the larger, more numerous round spots on the breast. Nest is similar to that of robin but is smaller and invariably has leaves in foundation and rootlets instead of grass in lining. Eggs are smaller and generally more pointed at one end than are robin eggs; also slightly paler than robin eggs (Harrison 1975).
Reproduction Comments: Nesting occurs in late spring and early summer. In Delaware, nesting peaks occurred in the last week of May and in the second week of July (Longcore and Jones 1969). Nest site selection and building is by the female alone; complete in about five days. No evidence birds ever use nest a second time. Clutch size is 2-5 (usually 3-4). Individual females typically produce two broods per year. Incubation, by female, lasts 12-14 days. Male usually guards nest when female absent. Young are tended by both parents, leave nest at 12-13 days. Pair remains together for second nesting (Harrison 1975). There is some evidence of occasional polygyny (Johnson et al. 1991).

In Delaware, of 142 "nesting attempts," 38% were successful and 58% of nests were destroyed by predators. The greatest nest success was associated with late season nests, spicebush and black gum vegetation, and with lower nest height (below 8.5 ft); 33% of eggs hatched, and 65% of hatched birds survived to leave the nest (Longcore and Jones 1969). In Maryland, Whitcomb et al. (1981) reported that thrushes produced two broods per year and had a reproductive success of 7.60. In Pennsylvania, nesting failure was caused by predation more than 95% of the time (Hoover 1992); 78% of nest depredation was attributed to small mammal/snake/avian nest predators and 22% to large mammal nest predators. Much work on reproductive success in wood thrushes has also been done by Hoover (1992) in relation to forest fragmentation.

Long-term population dynamics in a 15-ha woodlot were studied in Delaware by Roth and Johnson (1993). A sustained episode of reduced production per female and of an increased percentage of adults failing to produce any young coincided with a 4% annual decline in abundance between 1978 and 1987. When failure rate later dropped, return rate and abundance subsequently increased. Roth and Johnson (1993) concluded that a period of elevated, predation-caused failure prompted greater emigration by an ever-younger, less-site-faithful population.

Ecology Comments: POPULATION DENSITY: Published information on densities from breeding bird censuses in the southeastern U.S. between 1947 and 1979 were summarized by Hamel et al (1982): mean (standard error) density is listed as 14.2 (1.0) pairs per 40 ha with a density range of 1-41 pairs per 40 ha. In bottomland hardwood forests along the Roanoke River in eastern North Carolina, R. Sallabanks (unpubl. data) found thrushes to be most abundant in wide patches of levee forest where an average 1.14 singing males were detected per unlimited radius 10-min point count. Holmes and Sherry (1988) reported a mean (standard error) abundance in Hubbard Brook Experimental Forest, New Hampshire, of 4.64 (2.83) adult birds per 10 ha over the period 1969-1986 over which time the population showed a highly significant decline at Hubbard Brook (a similar pattern to that reflected for the state of New Hampshire population by BBS data). Whitcomb et al.(1981) found 125 males per sq km in an area in Maryland.

TERRITORIES: Freemark and Merriam (1986) listed the territory size as less than 2 ha. In wintering areas in southern Veracruz, some individuals were territorial and highly sedentary, often remained within 150 m of capture point for entire winter; other birds wandered (Rappole et al. 1989, Winker et al. 1990). Some birds return to same wintering areas in successive years (Rappole et al. 1989).

Habitat Type: Terrestrial
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: Y
Mobility and Migration Comments: Arrives in wintering areas in Middle America in October (Rappole et al. 1989); males first arrive in the southern U.S. in March-April (Terres 1980). Migrates through Costa Rica late September to mid-November and March-April (Stiles and Skutch 1989).
Palustrine Habitat(s): FORESTED WETLAND, Riparian
Terrestrial Habitat(s): Forest - Hardwood, Forest - Mixed, Shrubland/chaparral, Suburban/orchard, Woodland - Hardwood, Woodland - Mixed
Habitat Comments: BREEDING: deciduous or mixed forests with a dense tree canopy and a fairly well-developed deciduous understory, especially where moist (Bertin 1977, Roth 1987, Roth et al. 1996). Bottomlands and other rich hardwood forests are prime habitats. Also frequents pine forests with a deciduous understory and well-wooded residential areas (Hamel et al. 1982). Thickets and early successional woodland generally do not provide suitable habitat (Bertin 1977). Bertin (1977) found wood thrushes to require one or more trees at least 12 m tall, possibly for song perches, whereas Morse (1971) reported nesting in stands of young white pine with a canopy under 9 m in height. Nests usually are placed in a crotch or are saddled on a branch of a shrub, sapling, or large tree,

NON-BREEDING: In migration and winter, habitats include forest and woodland of various types from humid lowland to arid or humid montane forest, also scrub and thickets; primarily undisturbed to moderately disturbed wet primary forest; may wander into riparian forest and various stages of second growth (Rappole et al. 1989, Winker et al. 1990). Were recorded exclusively in forest in Atlantic lowlands of Costa Rica (Hagan and Johnston 1992). Winker et al. (1990) studied within-forest preferences of birds wintering in southern Veracruz and found that areas with gaps were preferred in this lowland rainforest; areas with heavy ground cover were also favored.

Adult Food Habits: Frugivore, Invertivore
Immature Food Habits: Frugivore, Invertivore
Food Comments: Eats insects and other invertebrates (e.g., snails), and small fruits; forages mainly on or near ground, sometimes in tree foliage (Terres 1980).
Adult Phenology: Diurnal
Immature Phenology: Diurnal
Length: 20 centimeters
Weight: 47 grams
Economic Attributes Not yet assessed
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Management Summary
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Stewardship Overview: Common throughout much of the eastern U.S. and most often found in deciduous or mixed forests with a fairly well-developed deciduous understory, especially where moist. Closed canopies are required. BBS data show this species to be most common in West Virginia, New Hampshire, and Maryland, with the Cumberland Plateau of the Appalachian Mountains being the most heavily populated Physiographic Region. Analyses of population trends show declines on regional and global scales. These declines are apparently due to loss and fragmentation of habitat, which has caused increased rates of nest predation and brood parasitism. In some areas of the Midwest, for example, thrushes are producing more cowbirds than thrushes, and avian nest predators such as grackles and crows are a serious threat. Tropical deforestation may also be a major threat to this species. Management recommendations are that forests be left unfragmented and low-volume selective cutting be used as an alternative to clear cutting where possible. Management needs include determination of key vegetation types associated with nesting success and a better understanding of minimum patch size requirements for source populations. Long-term monitoring of breeding productivity should be conducted wherever possible.
Restoration Potential: Although numbers are declining, there is no need of restoration in any state. However, should the need arise, restoration should be possible if fragmentation of habitat and edge effects can be minimized; this in turn should minimize the impact of cowbirds and nest predators.
Preserve Selection & Design Considerations: The key habitat requirement is a moist woodland understory of deciduous shrubs or saplings; bottomland and other rich hardwood forests are prime examples. Pine forests with a deciduous understory are also used, as are well-wooded residential areas. These habitat types should be a part of any preserve design considerations. As important as habitat type is preserve size. Nest predation and cowbird parasitism rates are higher in small woodlots and along the edges of larger tracts than in the interior of large tracts. Data from fragmented forests in the Midwest show that reproductive rates probably were well below levels necessary to compensate for adult mortality (Robinson and Wilcove 1994). Fragmented forests may therefore be population sinks with populations sustained by immigration from larger, unfragmented forest tracts. These data emphasize the importance of protecting large, unfragmented forests for breeding habitat.

Research on the effects of forest patch size on nesting success has direct implications for preserve design considerations. Hoover (1992) studied thrushes during 1990 and 1991 on 11 tracts of forest ranging in size from 9.2 ha to greater than 500 ha. Nesting success was significantly different between small and large forests (43% and 76%, respectively). Nest survival from 1990-1991 was positively correlated with forest area, forest core area, and percent forest within a 2-km radius of each study site. Nest depredation was significantly different between small and large forests (56% and 19%, respectively) and was the primary cause of nesting failure. Visitation by mammalian nest predators to scent-sign-posts was significantly different between small and large forests (41% and 14%, respectively), and relative abundance of avian nest predators was significantly higher on the small forests than on the large. Brood parasitism by cowbirds was also significantly different between small and large forests (13% and 4%, respectively) although had little influence on nesting success. Interestingly, Hoover (1992) found thrushes to be common on smaller tracts of forest, but that such birds had lower reproductive success because of high rates of nest depredation.

Large areas of forest are most favorable for breeding, though minimum patch size requirements are unclear. In Pennsylvania, nesting success was 86% in contiguous forest (> 10,000 ha), 72% in forest fragments larger than 100 ha, and 43% in small fragments of less than 80 ha; these differences were related to increased predation in the smaller forest tracts; cowbird parasitism had little influence on nesting success (Hoover et al. 1995). Whitcomb et al. (1981) reported that thrushes were present in small forest fragments (1-14 ha), but were almost twice as common if woodlots were larger than 70 ha. Thrushes were found by Galli et al. (1976) and Lynch (1987) to be more abundant in larger forest patches compared with smaller ones. In general, it appears that forest patches exceeding 100 ha are best suited for successful nesting because rates of nest predation and sometimes cowbird brood parasitism are lower. Thrushes require only small territories (< 1 ha) and seem to be able to maintain stable populations on small, isolated forest fragments in some cases (e.g., a 15-ha woodlot (Roth and Johnson 1993)). Some woodlots as small as 5 ha may be acceptable (Pinkowski 1991).

These results warn of the dangers of assuming that small fragments are acceptable just because they contain many birds; instead, we must determine reproductive success in addition to abundance relationships before we make accurate conclusions about habitat quality. Hoover (1992) concluded that to reverse decreasing population trends, land-use practices that maximize forest area and forest core area are needed.

Management Requirements: The effects of silvicultural practices such as clearcutting and selective logging on migratory songbirds may depend upon the landscape context (Robinson and Wilcove 1994). Preliminary evidence from the fragmented Shawnee National Forest of southern Illinois suggests that selective logging can have relatively little impact on thrushes. Robinson and Wilcove (1994) tentatively proposed that low-volume selective logging be used as an alternative to clearcutting. Logging roads should be closed and revegetated soon after harvest, and rotation times should be lengthened to permit regeneration of large, old trees.

The importance of protecting large, unfragmented forests for breeding habitat cannot be overstated. Where possible, forest preserves should be on the order of 10,000+ ha because cowbirds routinely commute up to seven kilometers between feeding and breeding sites. Fragmented forests might benefit from consolidation of ownership and forest regrowth within the largest tracts. Where necessary, cowbird control might be tried within the core of the largest tracts.

Vegetation patterns associated with successful reproduction need to be identified; then appropriate management plans can be devised. Thrushes are classified as closed-canopy obligate species and will tolerate uneven-age management forest stands (Crawford et al. 1981); single-tree selection (removal of mature trees as scattered individuals throughout the stand) and thinning understory trees that compete for root space will create favorable conditions for this species. Light diameter-limit cutting that removes only the best trees from the stand would be tolerated. Any intermediate or harvest cutting that opens the canopy will probably be detrimental.

Monitoring Requirements: Annual surveys of suitable habitat and known populations using point count censusing techniques are probably the best way to monitor this species. Long-term studies are obviously preferred. Studies should also monitor breeding productivity to provide critical information of factors affecting population recruitment and dynamics; it is imperative that we determine why reproductive success may be low, as well as why numbers of birds may be low. See Yahner and Ross (1995) for information on the use of taped-playback songs in transect surveys and nest searches (June is the best month).
Management Research Needs: Minimum area requirements for source populations seem to be the least understood aspect of management. Vegetation characteristics associated with nest-site selection and reproductive success also need to be quantified. Also, we need to understand better the role of tropical deforestation in the decline of regional thrush populations; habitat fragmentation on temperate breeding grounds cannot alone explain these declines.
Biological Research Needs: While a large body of research has contributed to understanding the habitat requirements and demography of this species on its breeding grounds, there remains a need for long-term studies on the implementation and effectiveness of conservation measures. Long-term studies are needed to document annual and lifetime reproductive success of individuals and the demographic trends exhibited by individual populations. In addition, the ecology of this species on its wintering grounds in the tropics remains poorly studied, a significant failing as this likely holds a key to understanding population declines. In particular, age-and sex-specific survival rates in the tropics remain unstudied and the consequences of habitat alteration have not been extensively documented. Specific links between wintering areas and breeding populations, sex-and age-partitioning of wintering habitat, and timing of migration by sex and age are largely unknown -- although recent geolocator studies show promise in this area of research (Stutchbury et al. 2009; also see Migration). Research should focus on connecting breeding demographics to non-breeding activities and migratory connectivity of the species (Evans, et. al. 2011).
Additional topics: Other research has concerned habitat selection and competition (Noon 1981), homing behavior (Able et al. 1984), taxonomy (Winker and Rappole 1988), mass variation in breeding birds (Johnson et al. 1990), and several aspects of wintering populations in southern Veracruz (Rappole et al. 1989, Winker et al. 1990).
Population/Occurrence Delineation
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Group Name: Passerines

Use Class: Breeding
Subtype(s): Foraging Area, Nest Site, Nesting Colony
Minimum Criteria for an Occurrence: Evidence of historical breeding, or current and likely recurring breeding, at a given location, minimally a reliable observation of one or more breeding pairs in appropriate habitat. Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.

Mapping Guidance: Breeding occurrences include nesting areas as well as foraging areas.

For swallows and other species that have separate nesting and foraging areas, separations are based on nest sites or nesting areas, not to locations of foraging individuals. For example, nesting areas separated by a gap larger than the separation distance are different occurrences, regardless of the foraging locations of individuals from those nesting areas. This separation procedure is appropriate because nesting areas are the critical aspect of swallow breeding occurrences, tend to be relatively stable or at least somwhat predictable in general location, and so are the basis for effective conservation; foraging areas are much more flexible and not necessarily static.

Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Significant dispersal and associated high potential for gene flow among populations of birds separated by tens of kilometers (e.g., Moore and Dolbeer 1989), and increasing evidence that individuals leave their usual home range to engage in extrapair copulations, as well as long foraging excursions of some species, make it difficult to circumscribe occurrences on the basis of meaningful population units without occurrences becoming too large. Hence, a moderate, standardized separation distance has been adopted for songbirds and flycatchers; it should yield occurrences that are not too spatially expansive while also accounting for the likelihood of gene flow among populations within a few kilometers of each other.

Be careful not to separate a population's nesting areas and foraging areas as different occurrences; include them in the same occurrence even if they are more than 5 km apart. Mean foraging radius (from nesting area) of Brown-headed Cowbird females was 4.0 kilometers in California, 1.2 kilometers in Illinois-Missouri (Thompson 1994). Yellow-headed Blackbirds, Brewer's Blackbirds, and probably Red-winged Blackbirds all forage up to 1.6 kilometers away from breeding colony (Willson 1966, Horn 1968). In one study, Brewer's Blackbirds were found as far as 10 kilometers from nesting area (Williams 1952), but this may be unusual.

For swallows and other parrerines with similar behavioral ecology, separation distance pertains to nest sites or nesting colonies, not to locations of foraging individuals. For example, nesting areas separated by a gap of more than 5 km are different occurrences, regardless of the foraging locations of individuals from those nesting areas. This separation procedure is appropriate because nesting areas are the critical aspect of swallow breeding occurrences, tend to be relatively stable or at least somwhat predictable in general location, and so are the basis for effective conservation; foraging areas are much more flexible and not necessarily static.

Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.

Unsuitable habitat: Habitat not normally used for breeding/feeding by a particular species. For example, unsuitable habitat for grassland and shrubland birds includes forest/woodland, urban/suburban, and aquatic habitats. Most habitats would be suitable for birds with versatile foraging habits (e.g., most corvids).

Date: 10Sep2004
Author: Hammerson, G.

Use Class: Migratory stopover
Subtype(s): Foraging Area, Roost Site
Minimum Criteria for an Occurrence: For most passerines: Evidence of recurring presence of migrating individuals (including historical) and potential recurring presence at a given location; minimally a reliable observation of 25 birds in appropriate habitat.

For swallows: Evidence of recurring presence of migrating flocks (including historical) and potential recurring presence at a given location; minimally a reliable observation of 100 birds in appropriate habitat (e.g., traditional roost sites).

Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 7 days annually.

EOs should not be described for species that are nomadic during nonbreeding season: e.g., Lark Bunting.

Be cautious about creating EOs for observations that may represent single events.

Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Separation distance somewhat arbitrary but intended to define occurrences of managable size for conservation purposes. Occurrences defined primarily on the basis of areas supporting concentrations of birds, rather than on the basis of distinct populations.

For swallows and other species with similar behavioral ecology, the separation distance pertains to communal roost sites rather than to foraging areas; the former tend to be more stable and specific over time than the latter.

Date: 03Sep2004
Author: Hammerson, G., and S. Cannings

Use Class: Nonbreeding
Subtype(s): Foraging Area, Roost Site
Minimum Criteria for an Occurrence: Any area used traditionally in the nonbreeding season (used for populations that are not resident in a location year-round). Minimally, reliable observations of 10 or more individuals in appropriate habitat for 20 or more days at a time. For G1-G3 species, observations of fewer individuals could constitute an occurrence of conservation value. Sites used during migration should be documented under the 'migratory stopover' location use class.

Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Separation distance is necessarily arbitrary but attempts to balance the high mobility of birds with the need for occurrences of reasonable spatial scope. Note that a population's roost sites and foraging areas are parts of the same occurrence, even if they are more than 5 km apart.

For swallows and other species with similar behavioral ecology, the separation distance pertains to communal roost sites rather than to foraging areas; the former tend to be more stable and specific over time than the latter.

Date: 03Sep2004
Author: Hammerson, G.

Use Class: Nonmigratory
Minimum Criteria for an Occurrence: Occurrences are based on evidence of historical presence, or current and likely recurring presence, at a particular location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals in or near appropriate habitat.

These occurrence specifications are used for nonmigratory populations of passerine birds.

Separation Barriers: None.
Separation Distance for Unsuitable Habitat: 5 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Significant dispersal and associated high potential for gene flow among populations of birds separated by tens of kilometers (e.g., Moore and Dolbeer 1989), and increasing evidence that individuals leave their usual home range to engage in extrapair copulations, as well as long foraging excursions of some species, make it difficult to circumscribe occurrences on the basis of meaningful population units without occurrences becoming too large. Hence, a moderate, standardized separation distance has been adopted for songbirds and flycatchers; it should yield occurrences that are not too spatially expansive while also accounting for the likelihood of gene flow among populations within a few kilometers of each other.

Be careful not to separate a population's nesting areas and breeding-season foraging areas as different occurrences; include them in the same occurrence even if they are more than 5 km apart. Blue jays have small summer home ranges but fly up to 4 kilometers to harvest mast (Tarvin and Woolfenden 1999). Flocks of pinyon jays range over 21-29 square kilometers (Ligon 1971, Balda and Bateman 1971); nesting and foraging areas may be widely separated. Tricolored blackbirds forage in flocks that range widely to more than 15 kilometers from the nesting colony (Beedy and Hamilton 1999).

Unsuitable habitat: Habitat not normally used for breeding/feeding by a particular species. For example, unsuitable habitat for grassland and shrubland birds includes forest/woodland, urban/suburban, and aquatic habitats. Most habitats would be suitable for birds with versatile foraging habits (e.g., most corvids).

Date: 10Sep2004
Author: Hammerson, G.
Notes: These specs pertain to nonmigratory species.
Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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NatureServe Conservation Status Factors Edition Date: 13Mar2014
NatureServe Conservation Status Factors Author: Dirrigl, F., Jr., G. Hammerson, and R. Sallabanks; revised by S. Cannings. Modified 2014-03-13 by Jue, Sally S.
Management Information Edition Date: 14Sep1993
Management Information Edition Author: SALLABANKS, R.; REVISIONS BY F. DIRRIGL, JR., G. HAMMERSON, AND D.W. MEHLMAN
Management Information Acknowledgments: Harry LeGrand, Jr., provided comments on an earlier version of this manuscript. I thank Roland Roth and Kevin Winker for providing reprints, Scott Robinson for providing preprints, and Margaret Brittingham for sending a copy of Jeff Hoover's unpublished dissertation. Thanks also go to all Heritage biologists who responded to the ESA questionnaire: Alabama - Mark Bailey; Arkansas - Cindy Osborne; Connecticut - Dawn McKay; Delaware - Christopher Heckscher; Florida - Steve Jones; Georgia - Jon Ambrose; Iowa - Daryl Howell; Illinois - Vernon Kleen; Indiana - John Castrale and Michelle Martin; Kansas - Bill Busby; Kentucky - Brainard Palmer-Ball; Louisiana - Steve Shively; Massachusetts - Brad Blodget; Maryland - Lynn Davidson; Maine - John Albright and Lindsay Tudor; Michigan - Mary Rabe; Minnesota - Mary Miller; Missouri - Brad Jacobs; Mississippi - Tom Mann; North Carolina - Harry LeGrand, Jr.; Nebraska - Mary Clausen; New Hampshire - Andy Cutko; New Jersey - Rick Dutko; New York - Kathy Schneider; Ohio - Daniel Rice; Pennsylvania - Barb Barton; Rhode Island - Rick Enser; South Carolina - John Cely; South Dakota - Doug Backland; Tennessee - Paul Hamel and Andrea Shea; Virginia - Sarah Mabey; Vermont - Chris Fichtel; and West Virginia - Barbara Sargent. Judith Soule of the Michigan Natural Features Inventory provided valuable advice on writing the ESA, Bruce Peterjohn of the U.S. Fish and Wildlife Service, Office of Migratory Bird Management, Patuxent Wildlife Research Center sent BBS data, and Melissa Morrison of The Nature Conservancy, Eastern Regional Office, sent ELLINK reports.
Element Ecology & Life History Edition Date: 05Apr1996
Element Ecology & Life History Author(s): SALLABANKS, R., AND G. HAMMERSON

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
Help
  • Evans, Melissa, Elizabeth Gow, R. R. Roth, M. S. Johnson and T. J. Underwood. 2011. Wood Thrush (Hylocichla mustelina), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:http://bna.birds.cornell.edu.bnaproxy.birds.cornell.edu/bna/species/246

    doi:10.2173/bna.246


  • Able, K. P., W. F. Gergits, J. D. Cherry, and S. B. Terrill. 1984. Homing behavior of Wood Thrushes (HYLOCICHLA MUSTELINA). Behavioral Ecology and Sociobiology 15:39-43.

  • Alabama Breeding Bird Atlas 2000-2006 Homepage. 2009. T.M. Haggerty (editor), Alabama Ornithological Society. Available at http://www.una.edu/faculty/thaggerty/BBA%20website/Index.htm.

  • Alabama Department of Conservation and Natural Resources, Division of Wildlife and Freshwater Fisheries. 2005. Conserving Alabama's wildlife: a comprehensive strategy. Alabama Department of Conservation and Natural Resources, Division of Wildlife and Freshwater Fisheries. Montgomery, Alabama. 303 pages. [Available online at http://www.dcnr.state.al.us/research-mgmt/cwcs/outline.cfm ]

  • Alabama Ornithological Society. 2006. Field checklist of Alabama birds. Alabama Ornithological Society, Dauphin Island, Alabama. [Available online at http://www.aosbirds.org/documents/AOSChecklist_april2006.pdf ]

  • Allen, C. R., S. Demarais, and R. S. Lutz. 1994. Red imported fire ant impact on wildlife: an overview. The Texas Journal of Science 46(1):51-59.

  • American Ornithologists Union (AOU). 1998. Check-list of North American Birds. 7th edition. American Ornithologists Union, Washington, D.C. 829 pages.

  • American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.

  • American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.

  • Andrews, R. R. and R. R. Righter. 1992. Colorado Birds. Denver Museum of Natural History, Denver. 442 pp.

  • Aquin, P. 1999. Évaluation de la situation des groupes taxonomiques des oiseaux du Québec. Ministère de l'Environnement et de la Faune. 13 pages.

  • B83COM01NAUS - Added from 2005 data exchange with Alberta, Canada.

  • Balda, R. P., and G. C. Bateman. 1971. Flocking and annual cycle of the piñon jay, Gymnorhinus cyanocephalus. Condor 73:287-302.

  • Barbour, R.W. et al. 1973. Kentucky Birds.

  • Bent, A. C. 1949. Life histories of North American thrushes, kinglets, and their allies. U. S. Nat. Mus. Bull.196. 452 pp., 51 pls.

  • Bertin, R. I. 1977. Breeding habitats of the Wood Thrush and Verry. The Condor 79:303-11.

  • BirdLife International. (2013-2014). IUCN Red List for birds. Downloaded from http://www.birdlife.org on various dates in 2013 and 2014. http://www.birdlife.org/

  • BirdLife International. 2004b. Threatened birds of the world 2004. CD ROM. BirdLife International, Cambridge, UK.

  • Bull, John. 1974. Birds of New York State. Doubleday, Garden City, New York. 655 pp.

  • COSSARO. 2013. Ontario Species at Risk Evaluation Report for Wood Thrush (Hylocichla mustelina). January 2013 (final). 16pp.

  • Cadman, M. D., P. F. J. Eagles, and F. M. Helleiner. 1987. The Atlas of Breeding Birds of Ontario. University of Waterloo Press, Waterloo, Canada. 617pp.

  • Carter, M., C. Hunter, D. Pashley, and D. Petit. 1998. The Watch List. Bird Conservation, Summer 1998:10.

  • Carter, M., G. Fenwick, C. Hunter, D. Pashley, D. Petit, J. Price, and J. Trapp. 1996. Watchlist 1996: For the future. Field Notes 50(3):238-240.

  • Crawford, H. S., R. G. Hooper, and R. W. Titterington. 1981. Songbird population response to silvicultural practices in central Appalachian hardwoods. Journal of Wildlife Management 45:680-92.

  • DICKINSON, MARY B., ED. 1999. FIELD GUIDE TO THE BIRDS OF NORTH AMERICA, 3RD ED. NATIONAL GEOGRAPHIC SOCIETY, WASHINGTON, D.C. 480 PP.

  • Desrosiers A., F. Caron et R. Ouellet. 1995. Liste de la faune vertébrée du Québec. Les publications du Québec. 122

  • Droege, S., and J.R. Sauer. 1990. North American Breeding Bird Survey, annual summary, 1989. U.S. Fish and Wildlife Service, Biological Report 90(8). 22 pp.

  • Dunn, E. H., C. M. Downes, and B. T. Collins. 2000. The Canadian Breeding Bird Survey, 1967-1998. Canadian Wildlife Service Progress Notes No. 216. 40 pp.

  • Evans, M., E. Gow, R. R. Roth, M. S. Johnson and T. J. Underwood. 2011. Wood Thrush (Hylocichla mustelina). The Birds of North America Online (A. Poole, ed.). Cornell Lab of Ornithology, Ithaca. Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu.bnaproxy.birds.cornell.edu/bna/species/246

  • Fauth, P. T. 2000. Reproductive success of Wood Thrushes in forest fragments in northern Indiana. Auk 117:194-204.

  • Fauth, Peter T. 1995. Wood Thrush Breeding Productivity Within a Fragmented Indiana Landscape. Prepared for the Indiana Department of Natural Resources, Division of Nature Preserves. 18 pp.

  • Florida Fish and Wildlife Conservation Commission2003, January 6. Florida's breeding bird atlas: A collaborative study of Florida's birdlife. http://legacy.myfwc.com/bba/species.asp.
     

  • Frazer, Carolyn. 1989. An Investigation of Bird-Habitat Relationships in Hoosier National Forest, Indiana. Unpublished. 45 pp.

  • Freemark, K.E., and H.G. Merriam. 1986. Importance of area and habitat heterogeneity to bird assemblages in temperate forest fragments. Biological Conservation 36:115-141.

  • Galli, A. E., C. F. Leck, and R. T. T. Forman. 1976. Avian distribution patterns in forest islands of different sizes in central New Jersey. The Auk 93:356-64.

  • Godfrey, W. E. 1986. The birds of Canada. Revised edition. National Museum of Natural Sciences, Ottawa. 596 pp. + plates.

  • Greenlaw, Jon S., Bill Pranty, and Reed Bowman.  2014.  Robertson and Woolfenden Florida Bird Species:  An Annotated List.  Special Publication No. 8, Florida Ornithological Society, Gainesville, FL.
     

  • Hagan, J. M., III, and D. W. Johnston, editors. 1992. Ecology and conservation of neotropical migrant landbirds. Smithsonian Institution Press, Washington, D.C. xiii + 609 pp.

  • Hamel, P. B., H. E. LeGrand Jr., M. R. Lennartz, and S. A. Gauthreaux, Jr. 1982. Bird-habitat relationships on southeastern forest lands. U.S. Forest Service General Technical Report SE-22.

  • Harrison, C. 1978. A Field Guide to the Nests, Eggs and Nestlings of North American Birds. Collins, Cleveland, Ohio.

  • Harrison, H. H. 1979. A field guide to western birds' nests. Houghton Mifflin Company, Boston. 279 pp.

  • Harrison, H.H. 1975. A field guide to bird's nests in the U.S. east of the Mississippi River. Houghton Mifflin Company, Boston, Massachusetts. 257 p.

  • Haw, James A. 1994. Nesting Bird Survey: Salamonie River State Forest. 2 pp.

  • Holmes, R.T., and T.W. Sherry. 1988. Assessing population trends of New Hampshire forest birds: local vs. regional patterns. Auk 105:756-768.

  • Hoover, J. P. 1992. Nesting success of Wood Thrush in a fragmented forest. Pennsylvania State University, State College, Pennsylvania. Ph.D. dissertation.

  • Hoover, J. P., M. C. Brittingham, and L. J. Goodrich. 1995. Effects of forest patch size on nesting success of wood thrushes. Auk 112:146-155.

  • Hoover, J.P., and M.C. Brittingham. 1993. Regional variation in cowbird parasitism of Wood Thrushes. Wilson Bulletin 105:228-238.

  • Horn, H. S. 1968. The adaptive significance of colonial nesting in the Brewer's Blackbird. Ecology 49:682-694.

  • Howell, S. N. G., and S. Webb. 1995. A guide to the birds of Mexico and northern Central America. Oxford University Press, Oxford, UK.

  • Hussell, D. J. T., M. H. Mather, and P. H. Sinclair. 1992. Trends in numbers of tropical- and temperate-wintering migrant landbirds in migration at Long Point, Ontario, 1961-1988. Pages 101-14 in J. M. Hagan III and D. W. Johnston (editors). Ecology and Conservation of Neotropical Migrant Landbirds. Smithsonian Institution Press, Washington, D.C.

  • Imhof, T. A. 1976. Alabama birds. Second edition. University of Alabama Press, Tuscaloosa. 445 pages.

  • JOHNSTON,R.F.1965. A DIRECTORY TO THE BIRDS OF KANSAS. MUSEUM OF NATURAL HISTORY, THE UNIVERSITY OF KANSAS. LAWRENCE.

  • Johnson, R. K., R. R. Roth, S. E. Kleiner, and C. R. Bartlett. 1991. A case of polygyny in the Wood Thrush. The Wilson Bulletin 103:509-10.

  • Johnson, R. K., R. R. Roth, and J. T. Paul Jr. 1990. Mass variation in breeding Wood Thrushes. The Condor 92:89-96.

  • Keast, A., and E.S. Morton. 1980. Migrant birds in the neotropics: ecology, distribution, and conservation. Smithsonian Institution Press, Washington, DC.

  • Ligon, J. D. 1971. Late summer-autumnal breeding of the piñon jay in New Mexico. Condor 73:147-153.

  • Longcore, J. R., and R. E. Jones. 1969. Reproductive success of the Wood Thrush in a Delaware woodlot. The Wilson Bulletin 81:396-406.

  • Lowery, George H. 1974. The Birds of Louisiana. LSU Press. 651pp.

  • Lynch, J. R. 1987. Responses of breeding bird communities to forest fragmentation. Pages 123-40 in D. A. Saunders, G. W. Arnold, A. A. Burbidge, and A. J. M. Hopkins (editors). Nature Conservation: The Role of Remnants of Native Vegetation. Surrey Beatty and Sons Pty Limited in association with CSIRO and CALM, Adelaide, Australia.

  • McAtee W.L. 1959. Folk - names of candian birds. National Museum of Canada. Folk - names of candian birds. National Museum of Canada. 74 pages.

  • Mirarchi, R. E., M. A. Bailey, T. M. Haggerty, and T. L. Best, editors. 2004. Alabama wildlife. Volume 3. Imperiled amphibians, reptiles, birds, and mammals. The University of Alabama Press, Tuscaloosa, Alabama. 225 pages.

  • Mirarchi, R.E., editor. 2004. Alabama Wildlife. Volume 1. A checklist of vertebrates and selected invertebrates: aquatic mollusks, fishes, amphibians, reptiles, birds, and mammals. The University of Alabama Press, Tuscaloosa, Alabama. 209 pages.

  • Moore, W. S., and R. A. Dolbeer. 1989. The use of banding recovery data to estimate dispersal rates and gene flow in avian species: case studies in the Red-winged Blackbird and Common Grackle. Condor 91:242-253.

  • Morse, D. H. 1971. Effects of the arrival of a new species upon habitat utilization by two forest thrushes in Maine. The Wilson Bulletin 83:57-65.

  • National Geographic Society (NGS). 1987. Field guide to the birds of North America. Second edition. National Geographic Society, Washington, D.C.

  • New York State Breeding Bird Atlas. 1984. Preliminary species distribution maps, 1980-1984. New York State Department of Environmental Conservation, Wildlife Resources Center. Delmar, NY.

  • New York State Breeding Bird Atlas. 1985. Final breeding bird distribution maps, 1980-1985. New York State Department of Environmental Conservation, Wildlife Resources Center. Delmar, NY.

  • New York State Department of Environmental Conservation. Checklist of the amphibians, reptiles, birds, and mammals of New York State, including their protective status. Nongame Unit, Wildlife Resources Center, Delmar, NY.

  • Nicholson, C.P. 1997. Atlas of the breeding birds of Tennessee. The University of Tennessee Press. 426 pp.

  • Noon, B. R. 1981. The distribution of an avian guild along a temperate elevational gradient: the importance and expresion of competition. Ecological Monographs 51:105-24.

  • Ouellet H., M. Gosselin et J.P. Artigau. 1990. Nomenclature française des oiseaux d'Amérique du Nord. Secrétariat d'État du Canada. 457 p.

  • Parker III, T. A., D. F. Stotz, and J. W. Fitzpatrick. 1996. Ecological and distributional databases for neotropical birds. The University of Chicago Press, Chicago.

  • Parks Canada. 2000. Vertebrate Species Database. Ecosystems Branch, 25 Eddy St., Hull, PQ, K1A 0M5.

  • Partners in Flight Science Committee. 2013. Population Estimates Database, version 2013. Available at http://rmbo.org/pifpopestimates. Accessed in 2014.

  • Peterjohn, B. J., J. R. Sauer, and S. Orsillo. 1995. Breeding bird survey: population trends 1966-1992. Pages 14-21 in E. T. LaRoe, G. S. Farris, C. E. Puckett, P. D. Doran, and M. J. Mac, editors. Our Living Resources. National Biological Service, Washington, D.C.

  • Peterson, R. T. 1980. A field guide to the birds of eastern and central North America. Fourth Edition. Houghton Mifflin Co., Boston, MA. 384 pages.

  • Pinkowski, B. 1991. Wood Thrush. Pages 356-7 in R. Brewer, G. A. McPeek, and R. J. Adams Jr. (editors). The atlas of breeding birds of Michigan. Michigan State University Press, East Lansing, Michigan.

  • Poole, A. F. and F. B. Gill. 1992. The birds of North America. The American Ornithologists' Union, Washington, D.C. and The Academy of Natural Sciences, Philadelphia, PA.

  • Price, J., S. Droege, and A. Price. 1995. The summer atlas of North American birds. Academic Press, New York. x + 364 pp.

  • Raffaele, H., J. Wiley, O. Garrido, A. Keith, and J. Raffaele. 1998. A guide to the birds of the West Indies. Princeton University Press, Princeton, NJ. 511 pp.

  • Rappole, J. H., M. A. Ramos, and K. Winkler. 1989. Wintering wood thrush movements and mortality in southern Veracruz. Auk 106:402-410.

  • Rappole, J. H., and D. W. Warner. 1980. Ecological aspects of migrant bird behavior in Veracruz, Mexico. Pages 353-393 in A. Keast and E.S. Morton, editors. Migrant birds in the neotropics: ecology, distribution, and conservation. Smithsonian Institution Press, Washington, DC.

  • Ridgely, R. S. 2002. Distribution maps of South American birds. Unpublished.

  • Ridgely, R. S. and J. A. Gwynne, Jr. 1989. A Guide to the Birds of Panama. 2nd edition. Princeton University Press, Princeton, USA.

  • Robinson, S. K. 1992. Population dynamics of breeding neotropical migrants in a fragmented Illinois landscape. Pages 408-18 in J. M. Hagan III and D. W. Johnston (editors). Ecology and Conservation of Neotropical Migrant Landbirds. Smithsonian Institution Press, Washington, D.C.

  • Robinson, S.K., and D.S. Wilcove. 1994. Forest fragmentation in the temperate zone and its effects on migratory songbirds. Bird Conservation International 4:233-249.

  • Rollfinke, B.F., R.H. Yahner, and J.S. Wakeley. 1990. Effects of forest irrigation on long-term trends in breeding-bird communities. Wilson Bulletin 102(2):264-278.

  • Roth, R. R. 1987. Assessment of habitat quality for Wood Thrush in a residential area. Pages 139-49 in L. W. Adams and D. L. Leedy (editors). Integrating man and nature in the metropolitan environment. Proceedings of the National Symposium on Urban Wildlife, Chevy Chase, Maryland, 4-7 November, 1986. National Institute for Urban Wildlife, Columbia, Maryland.

  • Roth, R. R., M. S. Johnson, and T. J. Underwood. 1996. Wood Thrush; The Birds of North America. Vol. 7, No. 246. American Orinithologists' Union. The Academy of Natural Sciences of Philadelphia.

  • Roth, R. R., and R. K. Johnson. 1993. Long-term dynamics of a wood thrush population breeding in a forest fragment. Auk 110:37-48.

  • Roth, R.R., M.S. Johnson, and T.J. Underwood. 1996. Wood Thrush (Hylocichla mustelina). In A. Poole and F. Gill, editors, The Birds of North America, No. 246. Academy of Natural Sciences, Philadelphia, and American Ornithologists' Union, Washington, DC. 28 pp.

  • Sauer, J. R., J. E. Hines, I. Thomas, J. Fallon, and G. Gough. 2000. The North American Breeding Bird Survey, Results and Analysis 1966 - 1999. Version 98.1, USGS Patuxent Wildlife Research Center, Laurel, MD. Available at: http://www.mbr.nbs.gov/bbs/bbs.html.

  • Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2014. The North American Breeding Bird Survey, Results and Analysis 1966 - 2012. Version 02.19.2014. USGS Patuxent Wildlife Research Center, Laurel, MD. http://www.pwrc.usgs.gov/.

  • Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2014. The North American Breeding Bird Survey, Results and Analysis 1966 - 2012. Version 02.19.2014 USGS Patuxent Wildlife Research Center, Laurel, MD.
     

  • Sauer, J.R., and S. Droege. 1992. Geographical patterns in population trends of Neotropical migrants in North America. Pages 26-42 in J.M. Hagan, III, and D.W. Johnston, editors. Ecology and conservation of Neotropical migrant landbirds. Smithsonian Institution Press, Washington, DC.

  • See SERO listing

  • Sibley, C.G., and B.L. Monroe, Jr. 1990. Distribution and Taxonomy of Birds of the World. Yale University Press, New Haven, CT. xxiv + 1111 pp.

  • Sibley, D. A. 2000a. The Sibley guide to birds. Alfred A. Knopf, New York.

  • Spahn, R. 1987. Highlights of the spring season. Kingbird 37(3):133-142.

  • Stevenson, H.M., and B.H. Anderson. 1994. The Birdlife of Florida. University Press of Florida, 891 pp.

  • Stiles, F. G. and A. F. Skutch. 1989. A guide to the birds of Costa Rica. Cornell University Press, Ithaca, New York, USA. 511 pp.

  • Tarvin, K. A., and G. E. Woolfenden. 1999. Blue Jay (Cyanocitta cristata). No. 469 IN A. Poole and F. Gill, editors. The birds of North America. The Birds of North America, Inc., Philadelphia, PA. 32pp.

  • Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.

  • Thompson, F. R., III. 1994. Temporal and spatial patterns of breeding brown-headed cowbirds in the midwestern United States. Auk 111:979-990.

  • Whitcomb, R. F., C. S. Robbins, J. F. Lynch, B. L. Whitcomb, M. K. Klimciewicz, and D. Bystrak. 1981. Effects of forest fragmentation on avifauna of the eastern deciduous forest. Pages 125-206 in R. L. Burgess, and B. L. Sharpe (editors). Forest island dynamics in man-dominated landscapes.

  • Williams, L. 1952b. Breeding behavior of the Brewer blackbird. Condor 54:3-47.

  • Willson, M. F. 1966. Breeding ecology of the Yellow-headed Blackbird. Ecological Monographs 36:51-77.

  • Winker, K., J. H. Rappole, and M. A. Ramos. 1990a. Population dynamics of the wood thrush in southern Veracruz, Mexico. Condor 92:444-460.

  • Winker, K., J. H. Rappole, and M. A. Ramos. 1990b. Within-forest preferences of wood thrushes wintering in the rainforest of southern Veracruz. Wilson Bull. 102:715-720.

  • Winker, K., and J. H. Rappole. 1988. The relationship between HYLOCICHLA and CATHARUS (Turdinae). The Auk 105:392-4.

  • Witham, J. W., and M. L. Hunter. 1992. Population trends of neotropical migrant landbirds in northern coastal New England. In J. M. Hagan III and D. W. Johnston (editors). Ecology and Conservation of Neotropical Migratory Landbirds. Smithsonian Institution Press, Washington, D.C.

  • Yahner, R. H., and B. D. Ross. 1995. Seasonal response of wood thrushes to taped-playback songs. Wilson Bulletin 107:738-741.

  • Zook, J. L. 2002. Distribution maps of the birds of Nicaragua, Costa Rica, and Panama. Unpublished.

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"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

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