Birders visiting open, marshy lakes and bays in the western United States can easily be stumped by Clark's grebes and western grebes. Once considered the same species, these two distinct birds are nearly identical and the unique characteristics each has are subtle. Since the species are also relatively uncommon in many areas, chances for extended observation are not always possible, making identifying these grebes particularly challenging. By understanding the differences between the two species, however, birders can learn to recognize both Clark's and western grebes.
When studying a grebe and trying to decide if it is a Clark's or western bird, there are a number of clues that can help distinguish each species.
- Face: Both species have a white face with a prominent black cap, but on Clark's grebes the red eye is surrounded by white while on western grebes the red eye is surrounded by black or dark gray. This can make it seem as though the western grebe has larger eyes, while the white plumage makes the eyes of Clark's grebes seem brighter and more colorful. In winter, however, the gray on western grebes can become much lighter, so careful observation is necessary.
- Bill: The dagger-like bill is one of the best distinguishing characteristics of these similar birds. The Clark's grebe has a bright yellow or bold orange-yellow bill, while the western grebe's bill is much darker and has a strong olive-green or gray tinge. Because of its coloration, a western grebe's bill may appear narrower or slightly upturned, especially in dim light.
- Neck: Both birds have a black stripe on the back of the neck connecting the dark cap to the dark body. Clark's grebes have a much thinner stripe, while it is thicker and more prominent on western grebes. This is most obvious if the birds are observed from behind, though it can also be seen from the extent of black, or lack thereof, that shows on the sides of the neck if the birds are seen in profile.
- Plumage: While Clark's and western grebes are almost identical in plumage, Clark's grebes are lighter overall when seen in good light, and their flanks are particularly lighter and may show as light gray or whitish. Western grebes are darker overall and can appear dark gray or black, with much darker flanks.
- Wings: When seen in flight, the wing patterns of grebes can be used for identification. Clark's grebes have extensive white flight feathers that show white coloring over most of the wing length, while western grebes have less white and show darker feathers toward the wingtips.
- Range: Both birds share the same range and habitats in western North America, but Clark's grebes are much rarer and have a smaller range spread, particularly to the north and east. Western grebes are more common and can be found further north and east more regularly, especially in summer.
- Voice: Both Clark's and western grebes are often found in large colonies where calls and sounds can be overwhelming. Clark's grebes have a single syllable "kreeek" call, while western grebes have a distinct two syllable "kree-eeek" call. Though both calls are similar, the number of syllables can be an important clue for a bird's identity.
The differences between Clark's grebes and western grebes are subtle but distinct. Birders who learn to tell the difference between the two species can appreciate their subtleties and enjoy finding both of them in similar habitats.
Field Identification Tips
In the field, mixed flocks of Clark's and western grebes are common, and that association allows birders to make close, direct comparisons between two birds to puzzle out which is which. Because the birds prefer large, open bodies of water, however, a spotting scope or high powered binoculars will be necessary to see the subtle plumage and marking differences on faraway birds. To ensure there are no identification errors, birders should try to watch the birds in different postures and changing lights to correlate the differences they see with each bird's identity.
With careful observation and attention to subtle details, it is possible to tell the difference between Clark's grebes and western grebes. Birders who take the time to learn each species will not only enjoy both grebes but will sharpen their bird identification skills in the process.
Quick Reference Identification Chart
|Characteristic||Clark's Grebe||Western Grebe|
|Face||Dark cap stops above eye||Dark cap extends below eye|
|Bill||Bright yellow or yellow-orange||Olive yellow and gray|
|Neck||Thin dark stripe on back||Thick dark stripe on back|
|Plumage||Gray with light flanks||Dark gray or black, darker flanks|
|Wings||More white in flight feathers||Less white in flight feathers|
|Range||More restricted, rare||More common, especially north and east|
|Voice||Single syllable "kreeek"||Two syllable "kree-eek"|