Olive-sided Flycatcher - Contopus cooperi
State Rank Reason (see State Rank above)
Species is apparently secure and not at risk of extirpation or facing significant threats in all or most of its range. Short-term declines have been observed.
- Details on Status Ranking and Review
ScoreF - 20,000-200,000 km squared (about 8,000-80,000 square miles)
Comment169,750 square Kilometers from Natural Heritage Program range maps
ScoreU - Unknown. Long-term trend in population, range, area occupied, or number or condition of occurrences unknown
CommentSignificant changes in forest management, including fire regimes have occurred since European settlement. This appears to have had a negative impact on populations, but the extend is unknown.
ScoreD - Declining. Decline of 10-30% in population, range, area occupied, and/or number or condition of occurrences
CommentBreeding Bird Survey Data are of moderate credibility, and provide weak support for a declining trend in observed individuals over the last decade for Montana. Trends for the Northern Rocky Mountains Region are of better quality and show significant decli
ScoreE - Localized substantial threat. Threat is moderate to severe for a small but significant proportion of the population or area.
CommentLoss of habitat due to forest management practices such as fire, and logging including salvage logging
SeverityModerate - Major reduction of species population or long-term degradation or reduction of habitat in Montana, requiring 50-100 years for recovery.
CommentRecovery of forest structure might take greater than 50 years
ScopeLow - 5-20% of total population or area affected
CommentConservatively 5-20% of habitat
ImmediacyHigh - Threat is operational (happening now) or imminent (within a year).
ScoreC - Not Intrinsically Vulnerable. Species matures quickly, reproduces frequently, and/or has high fecundity such that populations recover quickly (< 5 years or 2 generations) from decreases in abundance; or species has high dispersal capability such that extirpated populations soon become reestablished through natural recolonization (unaided by humans).
CommentSpecies nests at least once per year. Interannually variability due to changes in prey density indicate that species can disperse between areas of suitable habitat.
ScoreC - Moderate. Generalist. Broad-scale or diverse (general) habitat(s) or other abiotic and/or biotic factors are used or required by the species but some key requirements are scarce in the generalized range of the species within the area of interest.
CommentSpecies can be found in a diversity of montane and boreal forests throughout the west, but appears to select post-fire habitat over other forest habitat types when available
Raw Conservation Status Score
3.5 + 0 (geographic distribution) + 0 (environmental specificity) + -0.25 (short-term trend) + 0 (threats) = 3.25
The Olive-sided Flycatcher is a rather large (18 to 20 cm) flycatcher, with a large head and a proportionately short tail. Plumage is brownish-olive above (browner on juveniles) with a dull white to yellowish throat, breast, and belly. Streaked or mottled patches on the sides of the breast are dark and distinct from the lighter center. Sexes are similar, but may be separable in the hand by wing chord length, 96 to 109 mm (females) and 103 to 117 mm (males) (Howell et al. 1987).
The song is a loud, ringing whistle, rather easily imitated, delivered by the male generally from the top of an upright dead snag or living tree such as balsam fir (Abies balsamea
), spruce (Picea
spp.), tamarack (Larix laricina
), or other pointed tree, often the tallest in the area. Most observers use the mnemonic "quick-three-beers
" (Peterson 1980) to recall the song. The song is often heard as a foreshortened "free beer
." The call is a trebled "pip-pip-pip
" (Peterson 1980). Oologist V. Burtch told Bent (1942) that these notes "...seemed to be made mostly by the female in the vicinity of the nest and that all the nests he found were located after hearing these notes."
Head (1903) described another vocalization as being "more like a twitter, and was uttered during excitement, chiefly when the young were learning to fly. It sounded like "why, why, why
," repeated very rapidly a number of times. Sometimes this note was given as a prelude to the real song..." Bent (1942) also describes a two-syllable song, similar to the Eastern Wood-pewee's (Contopus sordidulus)
in quality: "The notes may be whistled as 'too-wee
' in ascending pitch, slightly suggesting the [Rufous-sided] towhee's (Pipilo erythrophthalmus)
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
The most distinguishing features to separate this species from other flycatchers are the song and white patches on the rump, when exposed. Otherwise, in the hand, Olive-sided Flycatchers can be separated from the wood-pewees (Contopus sordidulus and C. virens) by the longer (96 to 117 mm) wing, and from Greater Pewee (C. pertinax) by plumage (white tuffs on the sides of the rump), tail length (63 to 74 mm), and by the horn-colored to blackish lower mandible.
Western Hemisphere Range
eBird Occurrence Map
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Observations in Montana Natural Heritage Program Database
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")
(Observations spanning multiple months or years are excluded from time charts)
Arriving in May, the Olive-sided Flycatcher can be found in Montana through the summer months. With the longest migration route of any flycatcher to breed in North America, Olive-sided Flycatchers depart early, leaving for their wintering grounds in August (Altman 2000, Montana Bird Distribution Committee 2012). One September record exists of an individual reported southwest of Helena in 1991 (Montana Bird Distribution Committee 2012). Area specific information from the Bozeman area indicates fall migration dates from August 25 to September 10.
A species that generally breeds in the montane and boreal forests in the mountains of western North America, Olive-sided Flycatchers are highly adapted to the dynamics of a landscape frequently altered by fire. They are more often associated with post-fire habitat than any other major habitat type, but may also be found in other forest openings (clear cuts and other disturbed forested habitat), open forests with a low percentage of canopy cover, and forest edges near natural meadows, wetlands, or canyons (Hutto and Young 1999, Altman and Sallabanks 2000). Their affinity for forested edges near water may be a product of a higher presence of flying insects in these areas (Altman and Sallabanks 2000). They are a species common in spruce and aspen (Populus tremuloides), but are uncommon in mixed-conifer, ponderosa pine (Pinus ponderosa), pine-oak (Pinus-Quercus), and cedar-hemlock (Cupressaceae-Tsuga) forests, and rarely present in lodgepole pine (Pinus contorta) or pinyon-juniper (Hejl et.al. 1995, Casey 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 (common or occasional) 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 2012, 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 observation 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 listed as associated with 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 listed as 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.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific 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 assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
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. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
- 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
Human Land Use
Recently Disturbed or Modified
Shrubland, Steppe and Savanna Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Recently Disturbed or Modified
No information is availablae regarding the food habits of Olive-sided Flycatchers in Montana. Information from other studies in the species' range state foraging takes place primarily by hovering or sallying forth, concentrating on prey available via aerial attack. They generally launch these aerial attacks from a high, exposed perch atop a tree or snag. Like others in the flycatching guild, this bird is a passive searcher, looking for easy to find prey, but is also an active pursuer, attacking prey difficult to capture (Eckhardt 1979, Terres 1980).
With a diet made up almost entirely of flying insects, the Olive-sided Flycatcher has a special fondness for wild honeybees and other Hymenoptera (Beal 1912, Forbush 1927, Bent 1942, Terres 1980). Beal (1912) examined the contents of 69 stomachs, collected in 12 states and three provinces, and found that Hymenoptera comprised a substantial portion of the diet each month. The fewest Hymenoptera were taken in May, when they amounted to 74.5% of the stomach contents. The average Hymenoptera consumption for the season from April to September was 82.5%.
Of all birds examined during that survey, not one species subsisted exclusively on one order of insect. Winged ants were found in ten stomachs and entirely filled two of these. A few parasitic species were identified. Of special interest were 63 honeybees (Apis mellifera), found in 16 stomachs (25% of the entire sample). Other insects included beetles, Diptera (flies), Hemiptera (bugs), grasshoppers, moths, and dragonflies. In a study of the arthropod food of 25 species of forest-inhabiting birds in California from 1962-68, Otvos and Stark (1985) found that Coleoptera (beetles) were the most common food of the Olive-sided Flycatcher.
Currently no ecological information exists for Olive-sided Flycatchers in Montana. In other areas in the species' range, ecological information indicates they are usually territorial in nonbreeding areas (Stiles and Skutch 2003) and may display strong year-to-year site fidelity on the breeding (Altman 1997) and wintering grounds (Marshall 1988, Altman 1997). In a study of 16 insectivorous, aerially-foraging neotropical flycatcher species that are seasonally sympatric in the humid Caribbean lowlands of Costa Rica, Sherry (1984) found that migrants are more opportunistic while wintering than the year-round residents.
Records indicate direct evidence of breeding in Montana in July and August, with breeding behavior starting in May shortly after spring arrival (Montana Bird Distribution Committee 2012). Egg dates are probably similar to those for Colorado: June 16 to July 20. Johnsgard (1986) notes that fledged young have been reported in Jasper National Park as early as July 1, suggesting earlier nesting dates are possible in Montana than have definitively been recorded. The usual clutch size of three is confirmed in the state (Montana Bird Distribution Committee 2012).
Other reproductive studies in other areas of the species' range state courtship includes territorial fights between males, and males pursuing females across the canopies of coniferous forests. Courtship continues for at least two weeks until nest sites are chosen and pairing is completed (Bent 1942). Breeding males have a cloacal protuberance and breeding females a brood patch from April to August (Howell et al. 1987). The short subelliptical eggs of the Olive-sided Flycatcher are creamy-white, buff, or pink, and lightly wreathed on the broad end with brown or gray blotches (Harrison 1978). They are generally smooth, non-glossy and 22 by 16 mm in size (Baicich and Harrison 2005). The nest, a loosely formed cup of twigs and grasses, is sometimes comprised of lichens of the genus Usnea, and is lined with finer plant materials and hair.
Nests are placed most often in conifers (Harrison 1978, 1979), on horizontal limbs from two to 15 meters from the ground (Harrison 1979, James and Peck 1987). In Ontario, nests were found in black and white spruce (Picea glauca) (14 nests), jack pine (Pinus banksiana) (two nests), and balsam fir (one nest) (James and Peck 1987). Adirondack nests were built on an outer branch from 7.6 to 13.7 meters high in balsam fir or spruce (Peterson 1988). Even though the nest is bulky, it is well concealed and rather difficult to find. Clutches of three (rarely four) eggs are laid (Harrison 1978). Egg dates are June 6 to 24 in Ontario (James and Peck 1987), June 9 to 27 in New York, and June 14 in Vermont (Fichtel 1985). This bird is single-brooded and has an incubation period of 14 to 17 days in New York. Incubation is by the female. Nestlings leave the nest at 15 to 19 days (Harrison 1978), with New York State records of unfledged juveniles on June 22 and fledglings from July 10 to 24. Although young rarely fledge before the end of July, flycatchers can become very difficult to find as singing begins to slow during late June (Peterson 1988).
Management actions in Montana are currently limited by lack of conclusive information about the specific relationship between species' habitat use and reproductive success. It is unclear if stand replacing fire regimes or fires of less magnitude provide more appropriate habitat for successful reproduction (Casey 2000). In areas where fire suppression has reduced the heterogeneity of the forest, fire management techniques that promote a more historic pattern of disturbance would benefit the species (Casey 2000). Several other management techniques to benefit the species include retaining forested habitat around riparian and wetland habitats and retaining snags and large trees post-fire. Select logging practices that retain medium to large trees with a relatively open canopy closure may also provide appropriate habitat (Casey 2000).
- Literature Cited AboveLegend: View Online Publication
- Altman, B. 1997. Olive-sided Flycatcher in western North America: Status review. U.S. Fish and Wildlife Service, Portland, Oregon. 59 p.
- Altman, B. and R. Sallabanks. 2000. Olive-sided Flycatcher (Contopus cooperi). Species Account Number 502. 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
- Baicich, P.J. and C.J.O. Harrison. 2005. A guide to the nests, eggs and nestlings of North American birds. Second edition. Academic Press, New York.
- Beal, F.E.L. 1912. Food of our more important flycatchers. U.S. Department of Agriculture, Biological Survey Bulletin 44. 67 pp.
- Bent, A.C. 1942. Life histories of North American flycatchers, larks, swallows, and their allies. U.S. National Museum Bulletin 179. Washington, DC.
- Casey, D. 2000. Partners in Flight Bird Conservation Plan Montana Version 1.0. Montana Partners in Flight. Kalispell, Montana.
- Eckhardt, R.C. 1979. The adaptive syndromes of 2 guilds of insectivorous birds in the Colorado U.S.A. Rocky Mountains, Ecological Monographs 49(2):129-150.
- Forbush, E.H. 1927. Birds of Massachusetts and other New England States. Part 2: Land birds from bob-whites to Grackles. Massachusetts Department of Agriculture, Boston, Massachusetts. 461 pp.
- Harrison, C.J.O. 1978. A field guide to the nests, eggs and nestlings of North American birds. Collins, Cleveland.
- Harrison, H.H. 1979. A field guide to western birds nests. Houghton Mifflin Company, Boston, MA. 279 pp.
- Head, A. 1903. Nesting habits of two flycatchers at Lake Tahoe. Bird-Lore 5:153-155.
- 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., and J. S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service. U.S. Forest Service General Technical Report RMRS-GTR-32, Ogden, Utah.
- Johnsgard, P.A. 1986. Birds of the Rocky Mountains: with particular reference to national parks in the northern Rocky Mountain region. Colorado Associated University Press, Boulder, CO.
- Marks, J.S., P. Hendricks, and D. Casey. 2016. Birds of Montana. Arrington, VA. Buteo Books. 659 pages.
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- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- Otvos, I.S., and R.W. Stark. 1985. Arthropod food of some forest-inhabiting birds. Can. Entomol. 117(8):971-990.
- Peck, G.K., and R.D. James. 1987. Breeding birds of Ontario: nidiology and distribution, volume 2. Passerines. Royal Ontario Museum, Toronto, Ontario.
- Peterson, J.M.C. 1988. Olive-sided Flycatcher, (Contopus borealis.) Pp. 244-245 in R.F. Andrle and J.R. Carroll, editors. The atlas of breeding birds in New York State. Cornell University Press, Ithaca, NY.
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- Sherry, T.W. 1984. Comparative dietary ecology of sympatric insectivorous neotropical flycatchers Tyrannidae. Ecological Monographs 54(3):313-338.
- Stiles, F.G. and A.F. Skutch. 2003. A guide to the birds of Costa Rica. Comstock Publishing Associates, Cornell University Press, Ithaca. 511 pp.
- Terres, J.K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York. 1109 pp.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
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- Cheskey, T. 1987. Olive-sided flycatcher. Pages 250-251 in M. D. Cadman, P. F. J. Eagles, and F. M. Helleiner, editors. Atlas of the breeding birds of Ontario. Fed. Ontario Nat., University of Waterloo Press, Waterloo, Ontario.
- 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.
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