Marmaronetta angustirostris - Marbled Duck
Feather characters. Barbules are short (0.66-0.71 mm) and internodes contain lightly stippled pigment. Triangular nodes are located on distal end, covering less than 30% of the total barbule length. On proximal end, nodal structures are visible but undeveloped and hardly swollen, and thus too small to qualify as nodes (14-16 per mm). An abrupt increase in size of nodes is seen distally along the barbules. In a very few cases triangular nodes may not be present. Villi are absent and internodes are occasionally kinked. Minute prongs are present on distal end of barbules and on both sides of the pennulum. Occasionally minute prongs may be found proximal to triangular nodes.
Field characters. Size 39-42 cm. Weight 477 g (420-500) (Dunning, 1993). Slightly larger than Teal and with longer neck and bigger head. Pale brown plumage covered with creamy spots; broad dark stripe from eye to nape; nape feathers elongated to shaggy crest; no coloured speculum. Bill blackish with pale transverse line near tip. Legs green-brown. At a distance, appears as a uniform pale grey-brown duck with a dark eye patch. No eclipse plumage. Sexes similar.
Voice. Generally quiet; male has a low, nasal "eeeep"; female lacks loud quacking calls typical of Anas-species.
Distribution. Rare summer visitor. Map: see MapIt.
Habitat. Marismas, and small freshwater pools, floodlands and reservoirs with dense stands of fringing aquatic vegetation.
Food. Feeds mainly by up-ending in shallow water, taking seeds, tubers, and shoots of aquatic plants, and also worms, molluscs, insects and larvae.