Cormorants and darter
In lieu of an abstract, here is a brief excerpt of the content:

Cormorants and darters swim and dive underwater from the surface, to feed on fish, frogs and aquatic insects. Unlike most aquatic birds, they do not have waterproof body feathers, so quickly get cold and waterlogged. As a consequence, they can neither spend too long in the water, nor colonize areas with very low water temperatures. These birds habitually stand on open perches in the sun with outspread wings, both to dry the plumage and to warm the belly to aid digestion. All have short legs, large webbed feet, long wings, rather long tails and kinked necks. Cormorants have thick, hooked bills, while darters have slender, pointed bills. African Darter L: 90 cm (35") |WS: 115–128 cm (45–50") This cormorant-like waterbird is colloquially known as the ‘snakebird’ . It often swims with its body submerged, so the long, slender neck and slim bill stand up from the water, looking ominously serpentine . It is separated from cormorants by its more elegant shape, small head, slender neck and bayonet-shaped rather than hooked bill . In flight is has a longer tail and a much more slender head and neck than the White-breasted Cormorant . The adult is mostly black, its back adorned with white flecks and streaks . The male has a rufous neck with a white stripe from the eye along the side of the head . Females and juveniles are muted and brown . The African Darter is a common resident and is widespread, preferring placid waters to fastflowing rivers, and favours areas with dead trees or other platforms where it can perch . Cormorants and darter male female immature 18 White-breasted Cormorant L: 90cm (35") |WS: 120–160 cm (47–63") A bulky, strongly built cormorant with distinctive turquoise eyes . Adult is distinctly pied (blackish with a large white bib), while juvenile is browner and heavily speckled . White-breasted Cormorant is an uncommon resident that breeds in colonies with other waterbirds . Although mostly a fish-eater, it may occasionally eat a neighbour’s chick at the breeding colony . Reed Cormorant L: 52 cm (20") |WS: 85 cm (33") A small, long-tailed cormorant . Breeding adult is blackish and has a short black crest above the bill, whereas juvenile is browner overall . It can always be separated from White-breasted Cormorant by its much smaller size, red eyes, and proportionately longer tail . It is a common resident and widespread species . BIRDS OF RIVERS AND WETLANDS 19 ...


pdf