Size: Length; 48cm. Weight; 820g.

Habitat and distribution: Costa Rica to Argentina, Africa and Madagascar. Found in a wide variety of wetlands.

Breeding: Up to 13 eggs laid amongst long grass or reedbeds. Eggs hatch after an incubation period of around 28 days.

Diet: Vegetable matter and aquatic invertebrates.

• As their name suggests they do indeed have a distinct whistle call.
• The only duck in Madagascar with a white face.
• One of the 147 species of the Anatidae family, which are all ducks, geese and swans, more commonly known as wildfowl or waterfowl.
• Waterfowl bodies are adapted for a highly aquatic life, with webbed feet for swimming and a body shaped to improve buoyancy in the water and a thick covering of feathers for insulation. Different species specialise to fill different niches.  
• All species have an oil-gland which is used whilst preening to maintain waterproofing of their feathers; the oil-gland is highly developed in this family.
• All species have salt glands above each eye, which filter the blood and excrete excess salt.
• Wildfowl have had a long association with humans; the Mallard is the direct ancestor of almost all current breeds of domestic duck. Humans utilise this family for meat, eggs, and feathers and in some countries domestic duck are even kept around houses to control insect numbers.