GREBES Podicipedidae

6 species (1 vagrant)

Fairly small to fairly large diving birds of fresh and inshore coastal waters. Extremely short tail makes them appear tailless, with distinctive ‘round-sterned’ look; the latter is a useful pointer on distant birds that is often evident as they dive. Grebes generally dive by slipping gently below surface with wings held close to body, although most species will jump clear of water at times. Entirely aquatic, even constructing floating nests of plant matter anchored to emergent vegetation. Chicks are prominently striped, a feature partly persisting into juvenile plumage (especially on head/neck). Often quite gregarious outside breeding season, occurring in scattered concentrations. With exception of Little, generally silent outside breeding season. Feed mainly on fish and aquatic insects. In flight, relatively long neck is drooped below body level and large feet project beyond rear end of body. Flight is weak and fluttering over short distances, but quite strong when well underway.

Sexes similar, although females have less well-developed head plumes in adult summer plumage. Marked seasonal variation. Juveniles resemble winter adults (apart from retained downy striping on head/ neck). Complete post-breeding moult from late summer to autumn or early winter. Partial pre-breeding moult from winter to spring. Partial post-juvenile moult takes place from autumn to early winter. 

Tailless, round-sterned appearance combined with long, slim neck distinguishes grebes from all other waterbirds apart from divers. But note that when neck retracted onto shoulders distant small grebes on sea could be confused with auks or even Long-tailed Duck. Latter, however, have pointed rear end and dive with wings partly open (while diving grebes would have wings closed and neck extended). Larger grebes distinguished at distance from divers by shorter bodies with even more rounded sterns, longer and more slender necks, and, in flight, by white patches on upperwing. In adult summer plumage identification relatively easy, but in other plumages more difficult. Points to concentrate on are:

Head and bill shape • Head and neck pattern • Bill colour and pattern