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Roger Weller, geology instructor
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Duckbill
Platypus
Jaime Garcia
Historical Geology
Spring 2006
The Duck-Billed
Platypus
The duck-billed platypus is a very
unique creature in many ways. The
platypus can only be found in one area of the world,
In many ways, the platypus can be seen as a walking
contradiction because they are an egg-laying mammal. The platypus is a member of the Monotreme order;
this means that they platypus uses the same opening for reproduction and to
eliminate waste, this opening is referred to as the cloaca (Wikipedia).
The platypus is a fairly small animal and males are
typically larger than the females. The
adult platypus is on average 45- 60 cm in length and weighs between 2- 4.5
pounds. In comparison to other mammals
the platypus has a relatively low body temperature; for males it is 32* C (90*
F) and the body temperature for females is typically 38* C (100* F). The body is covered with brown fur that is
used as an insulator, allowing the platypus to remain warm while under water
(Wikipedia). Grooming is very important
to the platypus and as a result their fur is always in good condition.
The platypus has many distinctive body features that
separate it from any other animals; they have a soft bill, webbed feet, a flat,
wide tail, and males have a spur on the inside of their back ankles that
contains a poison gland. The soft,
rubbery-like bill of the platypus serves an essential purpose; the bill enables
the platypus to search and locate its prey.
The platypus is one of the few animals that use electro-perception to
locate its prey; the bill is electro- sensitive and it can sense the body
electricity of other animals (Wikipedia).
Although its tail is similar in appearance to the tail of a beaver, the
tail of the platypus serves a completely different function. The tail of the platypus is used to help it
maneuver through the water, allowing the animal to steer while swimming; the
tail is also used to store fat. The legs
of the platypus are very odd because they resemble the legs of an amphibian
much more than they do a mammal. The
legs of the platypus are short and they stick out of the sides of the body, rather
than underneath. Not much is known about
the function of the poisonous gland; it is suspected that it is used to injure
enemies or used when fighting for a mate.
As a result of having a relatively low body temperature, the platypus
has to resort to alternative methods of producing body heat. Body heat can be generated in two ways; the
platypus can increase it’s metabolism or it can use its blood circulation to
carry heat to the areas of the body that need it most and reducing it in the
areas where it is not as needed, such as the tail and bill (Agnew).
The
platypus can be found throughout most of
The platypus tends to be a solitary
animal, only coming together for the purpose of mating. The reason for their solidarity could also be
because the platypus is a relatively shy animal, one that attempts to avoid
confrontation whenever possible.
The
platypus spends the majority of its day foraging for food because it has to
consume a quarter of its own body weight each day (Wikipedia). During the summer season food is much more
plentiful than any other time of the year, so the platypus will consume more in
the summer and store the extra body fat to help sustain itself throughout the
winter. The platypus dives down to the
bottom of the river using its bill to dig and search for food; each dive
typically lasts up to 40 seconds (Agnew).
The platypus can make up to 80 dived each hour (Brilliantes). While swimming, the platypus closes their
eyes, ears and nostrils. The bill of the
platypus is used to sense the location of its prey. The platypus typically feeds on including
insects, crustaceans, mollusks and other small vertebrates. After catching its prey, the platypus will
wait until it has reached the surface to eat, storing the food in its cheeks
until that time. The platypus lacks
teeth, so it uses small horny pads to crush its food.
The platypus waits until it is two
years old to begin breeding; for males this is because they do not begin
producing sperm until that time. Mating
for females is more random because they do not breed every year. Just like most other mammals, breeding season
is typically in early spring. The
platypus lacks the sexual organs that are common to most mammals; both males
and females have a cloaca, with this opening the platypus is able to
successfully have intercourse and reproduce.
Little is known about the mating rituals of the platypus, except for
that it occurs in the water. Approximately
12-14 days after intercourse, the female will lay 1-3 eggs; each egg is
approximately 11 millimeters in diameter.
The appearance of these eggs very much resembles that of reptile
eggs. The female much incubate the eggs
by using her underbelly and tail. This
incubation period typically lasts between 10 and 12 days. The incubation period can be divided into
three stages of 
embryo development.
First, the embryo relies on the yolk sac for nutrition because it has no
functioning organs. It is during the
second period that the fingers and toes being to appear. Finally, in the third stage the egg tooth
appears (Wikipedia). The babies are born
with no hair and their eyes closed.
After the eggs have hatched, the mother must nurse her young. The platypus lacks nipples so the young feed
on milk that oozes from two ducts that can be found on the abdomen. Six weeks after the babies have left the
eggs, they will begin to resemble a platypus more because they are beginning to
grow fur and open their eyes. Within
4-5 months the mother must begin to wean her young so that they can leave the
burrow, by this time the babies have reached 80% of their adult size and 60% of
their adult weight (Agnew). Throughout
this whole process the male is absent because they have no role in caring for
the babies.
The duck-billed platypus is undoubtedly
one of the strangest mammals found on the Earth today. It is an egg-laying mammal with webbed feet
and bill. The explanation for why the
platypus evolved so differently from any other animal will most likely never be
known. All we can say is that is truly
an animal that is in a class all by itself.
Works Cited
Agnew, George. The Complete Platypus.
http://www.platypus.org.uk
Brillantes, Phil. Ornithorhynchus anatinus.
Animal Diversity Web. 20 Apr. 2006 http://animaldiversity.ummz.umich.edu/site/accounts/information/Ornithorhynchus_anatinus.html
Gray, Roberta. The Duck-Billed Platypus. 20 Apr.
2006 http://www.genevaschools.org/austinbg/class/gray/platypus/index.html
Platypus.
Platypus.
http://en.wikipedia.org/wiki/Duckbilled_platypus