Size: Length; 53cm. Weight; 1020g.

Habitat and distribution: Texas to Panama. Favours tropical lagoons.

Age: 8 years.

Breeding: Nest in tree cavities, occasionally on the ground. Lay up to 16 eggs which are incubated for around 31 days. Both parents share incubation and rearing.

Diet: Grass, seeds and occasionally small invertebrates.

• Unique among ducks, in that pairs often stay together for many years.
• As their name suggests they do indeed have a distinct whistle call.
• 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.