Naming and Classification
The cat-big little guy has many - also inappropriate - names
and a longer time it did not fit in one of the drawers of scientific
classification. In German language it is often called giant-glider.
The Filipinos use different names: "Kagwang" (Mindanao), "Caguan
"(Visaya-Region) or "Colugo." Most inappropriate is the name "Flying
lemur", because the giant glider can not fly actively, and there
exists no close relationship to the African Lemurs. Only the face
is lemur-like.
It could not be assigned - despite a corresponding tooth status to
the order of the carnivores, because the glider is a strong plant
vegetarian. Because of his inability of flattering or flying it
could not be added to the order of the bats. Additionally his flaps
of skin or membrane show no fingers or claws. It has a tail like a
squirrel, but as everyone knows squirrels cannot fly. Finally, the
biologists established in the class of mammalians on own order for
the animal. The name of the order is Dermoptera (~ skin-flyer),
the family is called Cynocephalidae (~ looking like a dog spout).
The family has only two species: the "Cynocephalus volans" from the
Philippines, and the "Cynocephalus variegatus", which could be found
especially on Borneo. The Borneo-species is somewhat bigger and has
more coloured spots on its fur.
Body
With an average weight of a little more than one kilogram, the
full-grown Philippine glider reaches a total length of approximately
70 cm; the tail takes almost half of the body length. With help of
the tail it can navigate the direction of gliding.
The Kagwang possesses a broad thin membrane, which covers nearly
the whole body including legs and tail up to the sharp claws.
Through spreading of the extremities, it is able to open the thin
flight membrane like a parachute. The flight membrane is not
movable; therefore the glider does not truly fly. The colouring of
the chinchilla-similar soft upper fur varies from grey-brown to
red-brown. It has dark bandings and is mottled silver-grey or
blackish. The head of animal is fox-similar, it shows a broad
forehead, a pointed spout, bigger eyes and rounded ears.
Behaviour
During the day, the Kagwang hides itself - rolled up in the crowns
of high trees or in tree caves. As a nocturnal animal it becomes
normally active with the appearance of twilight. We mentioned
already that it is a vegetarian. The Kagwang lives from special
leaves, buds and fruits, which deliver also the necessary liquid. An
oblong tongue and incisors make the food intake a lot easier. Leaves
are rather badly digestible; therefore it has a quite long intestine
of approximately four meters.
The Kagwang moves very seldom, and then only unintentional, on the
ground. Here, it moves very helplessly with its flaps of skin. It is
a tree animal. If it finds no more food on a tree it sails to the
next tree. The flight length depends also on the heights of trees.
In literature the flights can reach a maximal length between 60
and 136 meters. When it has reached the next tree, then the
glider climbs it up again quite slowly.
Up to 12 animals per hectare have already been counted, but they
live predominantly as loner. Mutual aggression can be noticed
outside the mating time. After a gestation time of approximately 60
days, a young comes to the world in, twins are seldom. In the first
six months, the female carries the young in its peritoneum. Only
after two to three years, the young is fully grown. So the
reproduction rate is rather small. It is told, that the very
rare Philippine Eagle is an natural enemy of the Kagwang and there
are reports that round about ninety percent of the eagles food
consist of gliders (1). It is still mysterious, how the
eagle can discover the rather hidden living glider in day time. In
captivity, a Kagwang reached once an age of 17.5 years before it
escaped.
Population
Species of gliders can be found in the rain forests of Vietnam,
Cambodia, Thailand, Philippines, Malaysia and Indonesia. In the
Philippines kagwangs are primarily living in the primary and
secondary forests in the eastern and southern parts of the country.
Especially the islands Basilan, Biliran, Leyte, Mindanao, Samar,
Siargao Bohol and Dinagat are mentioned.
Nationwide stock takings or long-term behavioural observations are
missing. However, the Philippine government has listed the
Philippine glider on the list of endangered animals and has
prohibited any trade. In former times the animals have been
hunted more strongly. The meat was regarded as a delicacy and the
fine soft fur was used for the manufacture of "funny caps". Gliders
have also been offered for sale in some pet shops in Manila.
However, it is known that the keeping of the animals in captivity is
difficult because they need particular food.
The deforestation of the rain forests is another danger for the
stock of animals. However, it was noticed that the glider can also
survive in reduced forests. Occasionally, the animals even invade
plantations of coconut, bananas or rubber trees. But we suppose that
they don't get not a warm welcome there.
(1)
http://www.answers.com/topic/colugo
©
Wolfgang Bethge, 2005
|