The western grebe (Aechmophorus occidentalis ) is a species in the grebe family of water birds. Folk names include "dabchick", "swan grebe" and "swan-necked grebe".
Western grebe fossils from the Late Pleistocene of southwest North America were described as a distinct species, but later ranked as a paleosubspecies Aechmophorus occidentalis lucasi. More recent study found them to fall within the variation now known to exist in today's birds.
The Western grebe is a large water bird found in North America. It is black-and-white in color, with a long, slender, swan-like neck and red eyes. This bird also has black around the eyes and a straight greenish-yellow bill. Western grebes are famous for their spectacular courtship displays, and their reedy calls are characteristic sounds of western marshes in summer.
Western grebes are widespread in western North America and occur in Canada, the United States, and Mexico. Northern birds migrate west to the coastal ocean in winter; birds in the southwest and Mexico may be permanent residents. Western grebes inhabit lakes, ponds, and brackish marshes that are mixed with marsh vegetation and open water. In winter, they mainly occur at sea along the coasts, in sheltered bays and estuaries.
Western grebes nest and migrate in flocks but the rest of the time they prefer to spend time singly. These birds are diurnal and spend most of their life in water; they rarely fly and are awkward when on land. Their legs are so far back on the body that it is very difficult for the birds to walk. Western grebes dive to catch their prey and often peer below the water before diving. Some smaller fish are impaled much like herons, with the bill, but others are grasped. Most are swallowed underwater, but some are brought to the surface, pinched, and swallowed. Outside of the breeding season, Western grebes are usually silent. However, when tending their young, parents use different types of vocalization to communicate. Ticking is one of the two and is used as an alarm signal. Parents carry their newly hatched young on their backs, and when the parents make a ticking sound, this is used as a signal for their chicks to hide their heads beneath the back of their parents and be silent. If chicks are greater than 4 weeks of age, they respond to the ticking by swimming or diving away on their own. Another vocalization noise is clucking, and these signals for food. When a parent clucks, the young respond to it by poking their head out of their parent back where they are on to receive food.
Western grebes are carnivores; they feed on carp, herring, mollusks, crabs, and amphibians, such as salamanders.
Western grebes are serially monogamous and pairs stay together during one breeding season. During the breeding season, these birds advertise themselves through ceremonies. "Rushing" ceremony, which can be also called water dance, race or run, is a ceremony that is the most frequent display to form a pair-bond. This is performed in pairs of either both male Western grebes or one male and one female. One of two individuals initiates "rushing", and the paired individual follows immediately and performs in synchrony. The birds lift their wings stiffly to the side and run in an upright position with its head held forward and neck curved. The males seem to perform the "rushing" together to attract the attention of females, and when one of two males attracts a female, a competition arises between males to get the female. One out of two withdraws and the "winning" male mates with the female by performing "rushing" together and continue to perform the Weed ceremony. Weed ceremony usually precedes the acts of mating and nest building. It is done after the pair is formed, and the ceremony begins as the mates bob their heads in the water. Then they dive in place and come back up to surface while holding weed on their beaks. This ceremony is continued until one of the pair flips away its weeds and drops to a normal position in the water. They continue their courtship with a Greeting ceremony. Greeting ceremony is similar to a "rushing" ceremony and involves dip-shaking, bob-shaking, bob-preening, and arch-clucking. Dip-shaking consists of dipping the head in the water and raising it up while rapidly waggling the bill side to side. Western grebes nest in colonies on lakes that are mixed with marsh vegetation and open water. The floating nests are made of plant debris and sodden materials, and the nest-building begins around late April through June. The construction is done by both sexes and is continued on throughout laying and incubation. The female lays 3-4 pale blue eggs and both parents incubate them within 21-28 days. The chicks are precocial; they leave the nest soon after hatching and are able to fly around 10 weeks later.
Western grebes are sensitive to human disturbances and birds leave their nests, thus leaving their unhatched eggs to be vulnerable for attacks. These birds are also threatened by oil spills due to which the number of grebes has been slowly declining in the last two decades.
According to the IUCN Red List, the total Western grebe population size is around 120,000-130,000 individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
