The platypus's diet consists
of yabbies(various insect larvae), shrimp, crayfish, earth worms, meal
worms, May flies, dragonflies, mussels, trout eggs, frog eggs, tadpoles,
small frogs and fish. The platypus searches for its food by diving
to the bottom of streams and rocking its head from side-to-side through
the mud. These dives last for about 40 seconds. When
forging on the bottom, the platypus swims with its eyes, ears, and nostrils
closed. It uses its electro-sensitive bill to locate and probe for
food. The platypus locates its prey underwater by sensing the electric
current created by the prey's muscle movements. This is why the platypus
is such an excellent hunter at night or in murky water.
  
  
The inner surface of the platypus's
stomach is lined with a cornified (horny) epithelium. There are no
glands in this area to produce hydrochloric acid and peptic enzymes which
provide the digestion of protein in other mammals. It has been suggested
that the breakdown of food in the stomach is assisted by the grinding action
of ingested mud.
Normally the platypus
eats up to half of its own body weight. It takes up to twelve hours
to collect this amount of food. In the summer the platypus is likely
to eat even more than this and stores the extra fat in its tail. This stored
fat is used as a food supply when additional food is needed in the winter
or for extra energy during the breeding and incubating season. Even
during the winter when it is cold, the platypus still goes swimming for
food. During the winter period a platypus generally eats 18% fresh
water shrimp, 4% caddis fly larvae, 12% fly larvae, 18% May fly larvae,
17 % Horsehair worms, and 1% small snails daily. In the summer it
generally consumes 64% caddis fly larvae, 18% fly larvae, 9% stone-fly
larvae, and 9% dragon fly larvae.
Several animals prey on
the platypus. These include foxes, crocodiles, birds of prey, goannas,
carpet pythons, large fish, cats, dogs, and dingos. Water rats sometimes
kill the young platypuses in the nesting burrow. Also floods sometimes
claim the lives of young platypuses. Other factors that kill platypuses
are water pollution, crab pots, and fishing nets. Due to the fact that
the platypus is specially adapted to its freshwater environment, the greatest
danger to it is the deterioration of its living environment by humans and
population growth. |
