Grebes are highly specialised waterbirds, usually seen swimming or diving singly, in pairs, or in loose flocks.
They rarely walk and tend to move clumsily on land. In flight, grebes appear humpbacked, with rapid wingbeats, an extended neck and their feet trailing below the body.
The Great Crested Grebe is the largest of the grebe species. Both sexes display a distinctive dagger-like bill, shiny white underparts, a black double crest and black-tipped chestnut tippets (frills) on the cheeks. Many adults retain their breeding plumage crest and tippets throughout the year. The female is slightly smaller than the male. Chicks and juveniles are easily recognised by their striped black-and-white head and neck.
Large, deep, open bodies of water provide the grebe’s preferred habitat. They are commonly found on freshwater ponds, rivers, lakes and wetlands, as well as coastal estuaries and bays. Although they appear quiet and peaceful on the water and are mostly silent, grebes are skilled hunters. Their diet includes fish, crustaceans and molluscs, and occasionally amphibians and insects.
One unusual behaviour of grebes is their habit of eating feathers. This helps aid digestion, and adults will also feed chewed feathers to their chicks to assist digestion and protect them from injury caused by sharp fish bones.
Breeding takes place on freshwater wetlands where there is a mix of open water for feeding and aquatic vegetation for nesting. During spring, courtship displays involve a series of harsh guttural and “mewing” calls, accompanied by elaborate ritualistic “water dances” that strengthen pair bonds. Breeding pairs are territorial and often remain bonded throughout the year.
Nests are usually located on or near vegetated margins of large bodies of water. They are constructed from masses of dead aquatic plants, weeds and mud, and are typically anchored to reeds, fallen branches or submerged stumps. Both parents incubate the eggs and care for the chicks, which are able to swim soon after hatching and are often seen riding on their parent’s back.
Although the Great Crested Grebe is currently listed as a species of “least concern”, it remains vulnerable to environmental changes that affect breeding habitats. These include altered drainage patterns, increased salinity, vegetation clearing, grazing pressures and groundwater extraction.
APRIL OUTINGS
Monday, April 6: Healey/Stanley properties, 110 Bellbird Rd, Granite Rock / Clifton Creek
Sunday, April 12: Bruthen Walking Trails, Main St, Bruthen – service road adjacent to Main St gardens/toilets
Monday, April 20: Point Fullarton and Eagle Point Track, Burden Place, off Paynesville Rd
Monday, April 27: Lake Guthridge and Sale Common car park at end of McIntosh Drive, Sale
