Clark’s Grebe, Aechmophorus clarkii
Clark’s Grebe, Aechmophorus clarkii. Photograph courtesy of Dr. Tom Bartol, Carlsbad, California, taken in the greater Salton Sea area of Southern California, January 2013.
Background and Identification
Clark’s Grebe, Aechmophorus clarkii, is a member of the Podicipedidae Family of Grebes. This species stands out to bird watchers and scientists for its striking appearance and elegant behavior. It is a close relative of the Western Grebe, Aechmophorus occidentalis, however, scientists know that the two species rarely interbreed and have substantial DNA differences. Clark’s Greb is well-known for its spectacular courtship displays, which involve elaborate dances on the water’s surface, such as the “rushing” ceremony, where pairs run side-by-side across the water. In Mexico, this species is called Achichilique de Clark.
This species is large in stature, with an average length of 55-75 cm and an average mass of 800-1,800 g. The sexes exhibit similar plumage, but females are smaller and have much shorter bills. It can be noted that the sexes can almost always be distinguished in the field by bill size, the bill of females is shorter and the mandible has an upturned appearance. Male bills are thicker and do not appear upturned. It has a long, slender neck, a sharp, pointed bill that is bright yellow-orange, and distinctive black-and-white plumage. The black cap of Clark’s Grebe stops above the eye, giving it a white face with a noticeable contrast.
Habitat and Geographical Range
This species prefers large freshwater lakes and marshes that have reeds and rushes. After breeding season they lose their flight feathers and become flightless until new flight feathers have grown in, at which point they migrate to saltwater and brackish habitats along estuaries, ocean shores, and rivers. They primarily consume fish, and many aquatic insects and crustaceans acquired from the upper levels of the water column.
Clark’s Grebe is a migratory bird in most of its range, breeding in the western and southwestern United States. During the non-breeding season, populations move outward to the coasts of California, Oregon, Washington State, and Baja California. Sedentary populations can be found in the interior of Mexico, south as far as Oaxaca. This species is most common in Mexico, found in the northern portions of Baja California and throughout all mountainous areas of the mainland at elevations up to 2,500 m (8,200 feet).
Common Misidentifications
Clark’s Grebe is most frequently confused with the Western Grebe, Aechmophorus occidentalis, due to their nearly identical size, shape, and behaviors. The key distinguishing features between the two are the color of the bill and the pattern around the eyes. Clark’s Grebe has a bright yellow-orange bill and a clear white face that does not have black below the eye, while the Western Grebe has a greenish-yellow bill and black extending below the eye.
Conservation Perspective
From a conservation perspective, Clark’s Grebe is currently considered to be of Least Concern with widely distributed populations. Populations, however, are currently decreasing. The current population is estimated to be less than 14,000 birds in the wild. This puts the bird on several conservation “watch” lists, increasing the efforts to study behavior and breeding patterns to understand why populations may be declining. Local populations may be impacted by threats such as habitat destruction, water pollution, and human disturbances. Their breeding and feeding areas can be affected by changes in water levels, quality, and availability due to damming, water diversion, and climate change. Conservation efforts for Clark’s Grebe focus on preserving wetland habitats, protecting key breeding sites, and maintaining water quality standards in lakes and marshes.