The Great crested grebe (Podiceps cristatus) is an aquatic diving bird noted for its elaborate mating display. It is the largest member of the grebe family found in the Old World, with some larger species residing in the Americas. These birds are excellent swimmers and divers and pursue their fish prey underwater.
Adult birds are unmistakable in summer with head and neck decorations. In winter, this is whiter than most grebes, with white above the eye, and a pink bill. Juveniles are recognizable by their plumage, with their heads featuring alternating black and white stripes. They lose these markings when they become adults.
Great crested grebes are found across Europe and Asia, parts of southern and eastern Africa, Australia, and New Zealand. These birds are resident in the milder west of their range but migrate from the colder regions. Populations in Africa, Australia, and New Zealand are mainly sedentary. Great crested grebes breed in vegetated areas of freshwater lakes, small pools, slow-flowing rivers, artificial water bodies, swamps, bays, estuaries, and lagoons. Wintering habitats include freshwater lakes, reservoirs, and sheltered coastal inshore waters such as brackish estuaries, and tidal lagoons.
Great crested grebes are diurnal birds and spend their day foraging, cleaning their plumage, and resting. They are excellent swimmers and divers, and pursue their prey underwater; they also may feed by submerging only their head. During the winter months, these birds are usually solitary but may sometimes gather in colonies of up to 5,000 individuals. Great crested grebes are highly aquatic birds and prefer to swim and dive rather than fly. They communicate with each other vocally using barking calls that sound like “rah-rah-rah”, clicking “kek” and a low growling “gorr”.
Great crested grebes are carnivorous (piscivorous, insectivorous) birds. They feed mainly on fish, but also insects, small crustaceans, small frogs, and newts.
Great crested grebes are serially monogamous; they form pairs that usually stay together for one breeding season. These elegant birds have an elaborate mating display, in which pairs raise and shake their head plumes, approaching each other with weed in their bills, they then rise breast to breast in the water and turn their heads from side to side. Like all grebes, they nest on the water's edge, since their legs are set relatively far back and they are thus unable to walk very well. Pairs may nest singly or in loose colonies. The nest is built by the male and the female together; it is usually a platform of aquatic plant matter floating on water or it can be built from the lake bottom in shallow water. Females usually lay two eggs and incubate them about 25-31 days. Chicks are precocial and are capable of swimming and diving almost at hatching. The adults teach these skills to their young by carrying them on their backs and diving, leaving the chicks to float on the surface; they then re-emerge a few feet away so that the chicks may swim back onto them. The young fledge about 70 to 80 days after hatching but stay with their parents for 11 to 16 weeks. They usually reach reproductive maturity at 1-2 years of age.
Great crested grebes were hunted almost to extinction in the United Kingdom in the 19th century for their head plumes, which were used to decorate hats and ladies' undergarments. In New Zealand, these birds were historically hunted for food. Current threats to Great crested grebes include habitat loss due to urban development, modification of lakes, oil spills, and avian influenza.
According to the IUCN Red List, the total Great crested grebe population size is around 915,000-1,400,000 individuals. The European population consists of 330,000-498,000 pairs, which equates to 660,000-997,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.
Great crested grebes are important predators of fish which includes most of their diet.
