10 component is measured in eigenvalue. The weights of linear equation of each
principal component PC are actually these eigenvectors.
2.5. Javan Gibbon
A short review of javan gibbon is given below. It comprises of taxonomy and morphology, social system, distribution, dietary and the pattern of spatial and
time utilization. This information is important for formulating the model.
2.5.1. Taxonomy and Morphology
According to Simpson 1945
in
Napier 1972, the taxonomy of javan gibbon is:
Species : Hylobates moloch
Audebert 1798 Genus
: Hylobates Family
: Hylobatidae Super-family : Hominoidea
Sub-ordo : Anthropoidea
Ordo : Primata
Class : Mammalia
Sub phyllum : Vertebrata Phyllum
: Chordata Kingdom
: Animalia Hylobatidae is a sub-group of primate which doesn’t have physical tail
which is common to other primates. They usually live in the top of forest layer. They have unique morphological hinds, which the front hinds are longer than back
hinds. They fully depend on their front hinds for moving or ranging from tree to tree, without reducing their rapidity in swinging and moving. This could indicate
that they already adapted to canopy and branches structure of trees. Javan gibbon can be identified by its silvery-grey hairs. The top of the head
is black as well as its face. The eyebrow is similar to the other hair. In Indonesia, the family Hylobatidae can be found in major islands, such as
Sumatera
H. syndactylus
or siamang
, H. agilis,
and
H. lar
, Kalimantan
H. muelleri and H. agilis
, Java
H. moloch
, and in Mentawai Island
H. klossii
.
11
2.5.2. Social System
Javan gibbon has a monogamous and family group system. In one group, usually 1-2 infants can be found. Sometimes sub-adult can be found in a group,
but it couldn’t stay longer but later excluded and establish new self-family group. Pregnancy period of javan gibbon is about 197 – 210 days. The elapsed
time after one birth to the second is about 3-4 years. Generally, they could live for 35 years.
2.5.3. Distribution
The latest information stated there are only 400 – 2000 javan gibbons left in Java Island; therefore, it has been classified as critically endangered species in
1996 IUCN Red List and listed in Appendix I CITES Eudey and MPSG2000, 2004. It is dispersed and only found in Java, especially in remnant and relatively
undisturbed mountain forest. As a top-arboreal, complete brachiated and frugivorous monkey, it needs an evergreen primary forest to live Napier and
Napier 1985, Napier and Napier 1967, Kappeler 1981, Kappeler 1984. There are only eight sites that still serve as Javan gibbon’s effective habitat - with large
enough population and inter population genetic flow - out of 30 sites that previously identified as their habitats in Java. Five of those sites located in West
Java, including Gunung Salak protection forest, Gunung Gede-Pangrango National Park, Gunung Halimun National Park, Ujung Kulon National Park, and
Gunung Simpang Nature Reserve Primack
et al
. 1998.
2.5.4. Dietary
