A mother with her newly hatched young. The young are born without fur
and claws and their eyes are not open. Image courtesy of the University
of Michigan's Animal Diversity Web, 1997.
A young platypus starting to grow fur but whose
eyes are still unopened. Image courtesy of the
Unique Australian
Animals Web site, 2003.
The male platypus's poisonous spur is very painful to humans and can
be lethal to some animals. Image courtesy of Tamar
Simon and the Discovery Channel Canada Online, 1999. Click on the
link for other images and two videos of platypus in the wild.
Australian
Platypus Conservancy: an Australia based group conducting research programs,
conservation programs and environmental education about the platypus.
Go to: http://www.totalretail.com/platypus
The
platypus is a monotreme. The monotremes are the only order of mammals
to lay eggs; in this, the platypus is similar to reptiles. Also like
reptiles, platypus produce vitamin C in the liver. The platypus produces
milk to feed its young (like all mammals). Also like mammals, monotremes
have a four-chambered heart and are covered in fur. The life span of
the platypus is not exactly known, but it is estimated between 15-18
years.
Reproduction: Normally
a solitary animal, the platypus is only social during mating season
(September). The platypus reaches sexual maturity at two years of age.
Platypus lay clutches of 1-3 eggs. The eggs have a thin, leathery shell.
The female incubates the eggs for 10-12 days till the young hatch. The
young have no fur and their eyes are not open. After six weeks the young
have fur and their eyes are open. Platypus milk is not excreted from
nipples, but from ducts at two areas on the abdomen (Tasmanian Parks
and Wildlife Service, 2002). After 4-5 months, the young are weaned.
Habitat: Platypus
live along the edge of the shallow rivers and streams where they forage
for food. The platypus prefer banks with plenty of natural plant growth.
Platypus (both sexes) dig individual resting burrows for protection
from predators. Females dig more complex nesting burrows for incubating
the eggs and rearing the young, who leave the burrow once weaned (Scott,
Anthony and Grant, Tom 1997).
Diet and Feeding: Platypus
eat grubs: shrimp, worms, yabbies, pea-shell muscles and aquatic insects.
They forage at night from the bottom of streams and ponds. Platypus
automatically close their eyes and ears in water. To locate prey, the
platypus use their bill. The platypus bill has hundreds of tiny receptors
which respond to touch and tiny electro-currents produced when invertebrates
move in water (Chambers Wildlife Rainforest Lodges, 2002). The young
have teeth but the adults have horny, rigid plates for crushing prey
(Missouri Botanical Gardens, 2002).
Predation and Defense:
Male platypus have a hollow, sharp single spine on each of their hind
legs. The spines secrete a lethal venom produced in a gland in the groin
(Chambers Wildlife Rainforest Lodges, 2002). Poison is produced at higher
levels during mating season, when the males are competing for mates
(Australian Platypus Conservancy, 2003). The spine can also be used
a defensive weapon against predators. The platypus's main predators
are large birds of prey, crocodiles, dogs, cats, and foxes. The young
in nesting burrows are threatened by pythons, water-rats, and guannas
(Australian Platypus Conservancy, 2003). The platypus spine is very
painful, but not lethal to humans (Tasmanian Parks and Wildlife Service,
2002).
Distribution: Platypus are found along the
eastern coast of Australia in Tasmania, Victoria, New South Wales and
Queensland. There is one introduced population in South Australia but
the platypus is otherwise extinct from that area.
Conservation
Status
The
platypus conservation status, as listed on the endangered species list
by the Australia and New Zealand Environmental Conservation Council,
is 'secure but faces future threat'. Most information sources list the
platypus as 'common but vulnerable'.
Conservation
Issues
Europeans
hunted the platypus for its fur which greatly reduced the numbers of
platypus. At the turn of the 20th century, however, trapping regulations
were imposed (Scott, Anthony and Grant, Tom 1997). Currently commercial
and illegal fishing nets pose a threat to the platypus, which are often
caught and drowned. Regulations increasingly limit the fishing industry
and regulate the size of nets to decrease the possibility of harming
platypus (Scott,
Anthony and Grant, Tom 1997).
The
Platypus, like many wild animals is affected by human litter. Plastic
rings, from a variety of sources can strangle, incapacitate or lacerate
the platypus in a variety of ways. This causes many injuries and some
deaths. In many suburban waterways, over 10% of platypus are affected
by various plastic rings (Australian Platypus Conservancy, 2003). Other
forms of human litter affect the platypus, particularly discarded machinery
which leaks gasoline and oil.
Encroaching
human habitation along streams and rivers where platypus make their
burrows has many strong effects on the platypus. Paths, whether paved
or unpaved, along waterways can lead to erosion, increased access to
burrows by predators, and vertical surfaces make it difficult for the
platypus to enter and exit the water. Decrease in vegetation along waterways
also affects the platypus. This can reduce prey for the platypus and
increase access to burrows by predators (Wild Watch, 2001). Another
danger posed by encroaching human development is PVC piping along waterways.
Platypus often enter open pipe ends and have difficulty turning around
and leaving, which inevitably leads to death. Simply putting mesh across
the opening of piping would prevent this danger. (Australian Platypus
Conservancy, 2003).
Residential runoff, including detergents
and soaps, fertilizers, and livestock wastes lead to increased organic
nitrogen and phosphorous levels in water. This affects the platypus
by poisoning prey and damaging their fur (Australian Platypus Conservancy,
2003). Simply controlling households wastes and limiting fertilizer
use to periods of low rainfall would reduce this threat to the platypus
and their habitat.
Conservation groups, universities
and some veterinarians conduct public education services about the platypus
and shallow stream habitats. Habitat clean up and other conscientious
efforts to maintain shallow rivers and streams will ensure that the
platypus does not become endangered.
Scott,
Anthony and Grant, Tom. Nov. 1997.
Impacts of water management in the Murray-Darling Basin on the platypus
(Ornithothynchus anatinus) and the water rat (Hydromys
chrysogaster).
