The Philippine Glider

(Cynocephalus volans)

 

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 eagle’s 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