Swainson's Thrush - Catharus ustulatus
FWP Conservation Tier
Medium-sized thrush with olive-brownish upperparts, distinct buffy eye-ring, white underparts and brownish black spotting on the throat and breast. Overall length 16.1 to 19.3 cm; mass 23 to 45 g. Although wings and tail may be somewhat browner than body, upperparts appear fairly uniform in color. Swainson's Thrush is best distinguished from all other thrushes by presence of buffy eye-ring and lores. The distinctive song and call also distinguish Swainson's Thrush from others. The flutelike song spirals upward, differing from the descending or variably pitched songs of related thrushes (Evans et al. 2000).
Summary of Observations Submitted for Montana
Number of Observations:
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Map Help and Descriptions
(direct evidence "B")
(indirect evidence "b")
No evidence of Breeding
(regular observations "W")
(at least one obs. "w")
(Records associated with a range of dates are excluded from time charts)
In the Bozeman area, normal migration periods are from May 20 to June 15 and August 15 to September 15.
In general, most strongly associated with coniferous forests. In western states, at the southern end of its range, the species inhabits mountain deciduous riparian or aspen forests. Described as a bird of mature forests. Canopy closure, understory cover, tree density, and a conifer component are important habitat attributes (Evans et al. 2000).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (high, medium, or low) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2001, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species’ range and habitat requirements;
- Examining the observation records for each species in the state-wide point database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of “observations versus availability of habitat”.
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were associated as using an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
High, medium, and low habitat quality was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species in the literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignments of habitat quality.
If you have any questions or comments on species associations with ecological systems, please contact Bryce Maxell at email@example.com
or (406) 444-3655.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: http://mtnhp.org/requests/default.asp
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species’ known geographic range.
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2001. The wild mammals of Montana. Special Publication No. 12. Lawrence, KS: The American Society of Mammalogists. 278 p.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana’s amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
- Commonly Associated with these Ecological Systems
Forest and Woodland Systems
Shrubland, Steppe and Savanna Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Wetland and Riparian Systems
Berries and insects. Breeding and spring migrating populations tend to be insectivorous; fall migrating and wintering populations more frugivorous (Evans et al. 2000).
Territory sizes of 1.7 to 3.3 acres in Douglas-fir or lodgepole pine forests in western Montana have been recorded.
Most frequently nests in understory, particularly in thickets of deciduous shrubs or conifer saplings; less frequently but consistently found greater than 3 m high on top of a horizontal branch away from the bole of a larger diameter tree. Eggs are ovate, blue to greenish blue with reddish or brown speckles and smooth in texture. Clutch size is 1 to 5 eggs with 4 being most common (Evans et al. 2000). Near Fortine, egg dates range from June 12 to July 20.
- Additional ReferencesLegend: View WorldCat Record View Online Publication
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- American Ornithologists' Union. 1998. Check-list of North American birds. 7th edition. American Ornithologists' Union, Washington, D.C. 829 pp.
- Aney, W.C. 1984. The effects of patch size on bird communities of remnant old-growth pine stands in western Montana. M.S. Thesis, Univ. Montana, Missoula. 98 pp.
- Dobkin, D. S. 1992. Neotropical migrant landbirds in the Northern Rockies and Great Plains. U.S.D.A. For. Serv. N. Region Publ. R1-93-34. Missoula, Mont.
- Dobkin, D.S. 1994. Conservation and management of neotropical migrant landbirds in the Northern Rockies and Great Plains. Univ. Idaho Press, Moscow, Idaho. 220 pp.
- ECON, Inc., Helena, MT., 1987, Wildlife and habitat characterization, Paupers Dream Mine Project Site, Lewis & Clark and Jefferson Counties, Montana. June 25, 1987. In Pangea Mining Co., Inc., Paupers Dream Project.
- Ehrlich, P., D. Dobkin, and D. Wheye. 1988. The birder’s handbook: a field guide to the natural history of North American birds. Simon and Schuster Inc. New York. 785 pp.
- Eng, Robert. L., 1976?, Wildlife Baseline Study [for West Fork of the Stillwater and Picket Pin drainages]
- Hejl, S.J. and L.C. Paige. 1994. A preliminary assessment of birds in continuous and fragmented forests of western red cedar / western hemlock in northern Idaho. In: Proceedings of interior cedar-hemlock-white pine forests: ecology and management. p. 189-197 Department of Natural Resource Sciences, Washington State University, Pullman, WA.
- Hejl, S.J. and R.E. Woods. 1991. Bird assemblages in old-growth and rotation-aged Douglas-fir/ponderosa pine stands in the northern Rocky Mountains: a preliminary assessment. Pages 285-292 in D. M. Baumgartner and J. E. Lotan, eds. Symposium proceedings, interior Douglas-fir: the species and its management. Wash. State Univ., Pullman.
- Hejl, S.J., R.L. Hutto, C.R. Preston, and D.M. Finch. 1995. Effects of silvicultural treatments in the Rocky Mountains. In: T. E. Martin and D. M. Finch, eds. Ecology and Management of Neotropical Migratory Birds. Oxford Univ. Press, New York. pp.220-244.
- Hutto, R. L. 1995. Composition of bird communities following stand-replacement fires in Northern Rocky Mountain (U.S.A.) conifer forests. Conservation Biology 9: 1041-1058.
- Hutto, R. L. and J. S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service. General Technical Report RMRS-GTR-32. U. S. Department of Agriculture, Forest Service, and Rocky Mountain Research Station, Ogden, UT. 72 pp.
- Johnsgard, P. A. 1992. Birds of the Rocky Mountains with particular reference to national parks in the northern Rocky Mountain region. Lincoln: University of Nebraska Press. xi + 504 pp.
- Johnsgard, P.A. 1979. Birds of the Great Plains: breeding species and their distribution. University of Nebraska Press, Lincoln. 539 pp.
- Jones, Peter W., and Therese M. Donovan. 1996. Swainson's Thrush (Catharus ustulatus). Species Account Number 261. The Birds of North America Online (A. Poole, Ed.). Ithaca, NY: Cornell Laboratory of Ornithology; Retrieved 3/25/2008 from The Birds of North America Online database
- Lenard, S., J. Carlson, J. Ellis, C. Jones, and C. Tilly. 2003. P. D. Skaar's Montana Bird Distribution, 6th Edition. Montana Audubon: Helena, MT, 144 pp.
- Mannan, R.W. and E.C. Meslow. 1984. Bird populations and vegetation characteristics in managed and old-growth forests, northeastern Oregon. J. Wildl. Manage. 48(4): 1219-1238.
- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- Munts, M.A. 1994. A comparison of bird communities between an untreated control and two timber harvest treatments in western Montana. M.S. Thesis, Univ. Montana, Missoula. 49 pp.
- Tobalske, B.W., R.C. Shearer, and R.L. Hutto. 1991. Bird populations in logged and unlogged western larch/Douglas-fir forest in northwestern Montana. Res. Pap. INT-442. Ogden, UT: U.S.D.A. Forest Service, Intermountain Research Station. 12pp.
- U.S. Forest Service. 1991. Forest and rangeland birds of the United States: Natural history and habitat use. U.S. Department of Agriculture, Forest Service Agricultural Handbook 688. 625 pages.
- Westech, Inc. [Western Technology and Engineering]. 1989. Reconnaissance of terrestrial wildlife resources in the Pauper's Dream project vicinity, Aug. 1988. Prepared for Hydrometrics, Inc., Helena, MT. 22 pp.
- Western Technology and Engineering, Inc. (WESTECH). 1994. Wildlife Monitoring Absaloka Mine Area Annual Report, 1993. Montana SMP 85005. OSMP Montana 0007C. Mar. 12, 1994.