The platypus native to Australia is a wary animal and is rarely seen in the wild. Many interesting facts related to its eating habits have been revealed since substantial research into this animal began in the 1990's.
The platypus diet consists mainly of small invertebrates and crustaceans located on the bottom of creek beds and lakes. Yabbies, (small freshwater crayfish), earth worms, meal worms, fly larvae, dragonflies, mussels, fish eggs, tadpoles, small frogs and fish are all a source of nutrition for the platypus. The platypus will eat between seventeen and twenty-five percent of its body weight each day. They store additional fat in their tail to be used when food is short, extra warmth is required or during the breeding season. A thick tail is the sign of a healthy platypus with a plentiful food supply.
As the platypus' main food source is located underwater, the platypus must dive to find its food and it has a number of physical characteristics to assist with this. Its webbed feet and flat tail assist in swimming and diving and its waterproof coat traps a layer of air to provide insulation against the cold in winter. In addition its red blood cells carry larger amounts of oxygen rich hemoglobin than other mammals allowing the platypus to go without air for longer periods of time.
The platypus closes its eyes, nose and ears when underwater relying on electro-location to seek out its prey. Only ever seen previously in sharks and rays this ability is unique among mammals. The platypus bill is covered in thousands of tiny holes which allow them to detect the electrical currents emitted by the muscle movements of their prey. Underwater footage has shown the platypus moving its head from side to side to determine the location of its prey.
Only the baby platypus has rudimentary teeth which are replaced with bony plates on the upper and lower jaw of the adult. During a dive the platypus will gather food with its bill and move it to cheek pouches. When it returns to the surface the food will be moved back to its mouth where it is ground down before being swallowed. Shells mud and other inedible products are expelled through serrations on the sides of the jaw during the grinding process. The platypus does not produce acids or enzymes that aid in digestion like other mammals; instead the stomach has a horny lining which further grinds the food before absorption.
The platypus is a nocturnal animal and because of their electro-location they are excellent hunters in the dark. They will usually leave their burrows at dusk to forage for ten to twelve hours, returning around dawn. During a night's hunting they spend between thirty and sixty seconds diving beneath the water then ten to thirty seconds at the surface grinding and swallowing their food when the pattern is repeated again.
Although the platypus is common all along the east coast of Australia they are considered vulnerable due to the continued loss of their freshwater habitat. Damming, drainage and pollution are all contributing to the reduction of their natural environment particularly in urban areas. As a result many urban water programs are now being implemented to restore the water and water quality required to support these unique and intriguing animals.