Clark's Grebe - Aechmophorus clarkii
Sexes similar in size and plumage. Clark's Grebe possesses a black crown, yellow bill, a narrow body with a long and thin white neck; back of neck gray. Top of body is mostly gray with speckled white spots. Coverts white with speckled gray.
Clarks Grebe best distinguished from the Western Grebe by having white up the side of the head to include the eye (the black crown of Western Grebe extends down the side of the head to include the eye) and a yellow bill (not yellowish-green).
Breeding range extends through southern Canada, the Dakotas, Montana, and Idaho into eastern Oregon, and south into Nevada andf California. During winter Clark's Grebe is found along the Pacific coast to central Mexico, and inland where there is open water.
Summary of Observations Submitted for Montana
Number of Observations:
(Click on the following maps and charts to see full sized version)
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)
Migratory. Spring migration appears to occur from late April to early May (earliest record 21 April), autumn migration during September and October (latest record 10 November) (Montana Bird Distribution Committee 2012). Information limited because of confusion of this species with Western Grebe.
Clark's Grebes are reported breeding only at very large lakes and reservoirs in Montana. Nesting on Lake Helena was near mid-lake on mats of aquatic plants that had reached the surface.
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 firstname.lastname@example.org
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.
Diet consists of mainly fish but also aquatic invertebrates along with a few amphibians (Storer and Nuechterlein 1992).
BBS is not suitable for monitoring this species in Montana. During surveys of 133 wetland sites in 2009 and 2010 (Wightman and Tilly 2010), Clark's Grebe was reported breeding at two sites on large lakes and marshes; Freezeout Lake WMA, Ninepipes NWR. Montana colonies appear to be relatively small, usually with fewer than 10 breeding pairs; two pair were reported in 2010 at Ninbepipies NWR, three pair at Freezeout Lake WMA (Wightman and Tilly 2010).
Single brooded species with three to four eggs per brood. Incubation period 23 days. Young able to fly 63 to 77 days after hatch (Storer and Nuechterlein 1992). In Montana, nests reported 16 May to 3 July, chicks 11 to 26 July (Montana Bird Distribution Committee 2012). Hybridization may occur, as there is one report of an adult Clark's Grebe tending young with a Western Grebe.
Clark's Grebe is poorly monitored in Montana and little is know about population status and abundance. Annual surveys would be useful to track distributions and numbers (Casey 2000). Need to differentiate this species from the Western Grebe. Management schemes should allow for manipulation of emergent growth patterns. Ideal nesting areas provide thick, but water-interspersed, clumps of emergents that block wave action (Storer and Nuechterlein 1992).
Threats or Limiting Factors
Degradation of wetlands, chemical contaminants, winter kill of fish and oil spills along coastal wintering areas.
- Literature Cited AboveLegend: View WorldCat Record View Online Publication
- Casey, D. 2000. Partners in Flight Draft Bird Conservation Plan Montana. Version 1.0. 287 pp.
- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- Storer, R.W. and G.L. Nuechterlein. 1992. Western grebe (Aechmophorus occidentalis). In: The Birds of North America No. 26. A. Poole and F. Gill, eds. The Academy of Natural Sciences, Philadelphia and The American Ornithologists Union, Washington, D.C.
- Wightman, C. and F. Tilly. 2010. Montana’s colonial-nesting waterbird inventory 2010 annual report. U.S. Fish and Wildlife Service and American Bird Conservancy. 8 pp.
- Additional ReferencesLegend: View WorldCat Record View Online Publication
Do you know of a citation we're missing?
- American Ornithologists' Union. 1998. Check-list of North American birds. 7th edition. American Ornithologists' Union, Washington, D.C. 829 pp.
- 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.
- 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.
- Montana Dept. of Fish, Wildlife and Parks. Region Four., 1996, Draft Environmental Analysis for Weed Management.
- Storer, R. W., and G. L. Nuechterlein. 1992. Clark's Grebe (Aechmophorus clarkii). Species Account Number 026b. 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
- Wassink, J. 1991. Birds of the Central Rockies. Mountain Press Publishing Co., Missoula, MT.
- Wright, P.L. 1996. Status of rare birds in Montana, with comments on known hybrids. Northwestern Naturalist 77(3):57-85.