Apart from several studies on status and distribution(Kurup, 1978; Balakrishnan,1984;Ali,1985; Karanth, 1985,Bhat,1993; Easa etal.,1996; Ramachandaran and Joseph ,1998) very few ecological and demographical investigations have been attempted (Sugiyama,1968;
Green and Minkowski, 1977; Kumar,1987; Menon, 1993; Singh et al.,1999). A brief study on the feeding  and ranging pattern of selected lion- tailed macaque troops was conducted by Ramachandran in 1990. No detailed investigation has been carried out yet regarding  the ecology and behavior of lion- tailed macaque in an undisturbed habitat in the Kerala part of the Western Ghats, where more than half of its wild population survives. It is therefore essential to document the ecological as well as behavioral peculiarities of this endangered species. In this paper  we observe the ecology and behavior of lion- tailed macaque and find how it has evolved to suit its life in the viable habitats like the forests of Silent Valley.

The Lion- Tailed Macaque   
The lion- tailed macaque is one of the most endangered primates of India , confined in distribution to the rainforests of southern Western Ghats. Habitat  specialists , they have adapted themselves to the evergreen environments available in the south Indian states of Kerala, Karnataka and Tamil Nadu, It has recently been estimated that only 3,000 to 4,000 individuals survive in the wild(kumar)et al.,1995). But most of the wild population exists as small populations due to extensive habitat fragmentation . Factors such as habitat fragmentation , reduced patch size and isolation of populations are leading to inbreeding , depression and vulnerability to random events, making the lion- tailed macaque a highly endangered species. Like all other macaques, they are omnivorous with a preponderance of wild fruit in their diet. Lion- tailed macaques are distinctive  in having the least amount of foliage in their diet compared to other macaques . This is one of the most important reasons as to why they are restricted to evergreen forests. This kind of habitat with a multi layer canopy system can provide a year around food supply of mainly fruits and seeds for this macaque . Any deterioration in the quality of the habitat , as  well as various  factors affecting their continuity, will ultimately be a serious  threat to the long term existence of the population. It has been noted that Ashambu hills in the extreme south, and Silent Valley to the north of Palakkad gap in Western Ghats are the only two viable habitats left for this endemic primate.

Lion Tailed Macaque in Silent Valley Forests

A three year intensive field study about the demographical as well as ecological aspects of lion- tailed macaque, conducted in the rain forests of Silent Valley from 1993 to 1996 resulted  in some interesting discoveries. There were fourteen lion- tailed macaque troops with 275 individuals thriving in Silent Valley forest in 1996, having an average troop sized 20 individuals. The troops were found only in certain tree association areas like cullenia exarillata-Palaquium elliptium ellipticum, Mesua ferrea-Palaquium ellipticum, and Mesua ferrea Calophyllum elatum occouring in the valley.
The adult sex ratio strongly favored  females at 5:1. Immature individuals , including subadult males, formed 47% of the population. Three  years of the population data showed a low birthrate  (0.22/adult female/ year) and a very high survival rate (0.98/individual /year) showed a positive sign of population growth. These  features , especially the low birthrate and high survival rate, are quite characteristic of lion- tailed macaque populations in undisturbed habitats (Kumar ,1987)
Modeling and simulation exercises were done using the data from Silent Valley troops and it was found that the population is viable , facing no serious threats in the next 100 years (Lacy et al, 1996)This is attributed mainly to the good habitat quality and continuity of the forests. As there are no human habitations inside the national park, anthropogenic disturbances are kept to the minimum. After the establishment of the area as a national park, total protection of these forests was given prime importance. Some of the adjacent areas are susceptible to fire and the forest department  has  adopted various preventive measures such as making firelines to keep fires under control and prevent them from penetrating into the national park boundaries. These steps have had a tremendous impact on the forest, which in turn accelerates the regeneration process. This kind of a regeneration in the low level grasslands in between the Cullenia dominant vegetation is vital as these fast regeneration areas would definitely increase the potential lion –tailed macaque habitat

Feeding ecology
The details on the feeding ecology of lion –tailed macaque in Silent Valley National Park come from the main study troop at Neelikal over a period of two years from 1994-1996. The troop was followed from dawn to dusk for 5 days in each month. Data on activity  patterns and feeding behavior were collected using the instantaneous scan method (Altmann, 1974). A preponderance of plant matter (91%) was observed in the diet. Ninety two plant species formed the principal part  of its diet, apart from the animal matter. The plant species included 62 trees. 10 lians, 8 shrubs, 6 fungi,3 lichens and 3 parasitic plant species. Among  these, the most extensively used plant species in the diet composition were flowers and seeds of Cullenia exarillata , (20.4%) , flowers and fruits of Palaquium ellipticum (7.4%), figs of ficus beddomei (5.5%), fruits of Dryetes elata (4%) and seeds of Macaranga indica (3.6%)
The diet of lion –tailed macaque in its undisturbed rainforest habitat is comprised of only evergreen species and these primates seldom range for food in the adjacent deciduous forests. Moreover , their heavy dependence on  the typical evergreen species  like Cullenia exarillata and Palaquium ellipticum proves their affinity towards those species. But  in addition to the typical evergreen  food species , the consumption of the fruits of certain heliophytes like Macaranga indica shows some sort of flexibility of the macaque’s diet. Thus the study clearly indicates that it can adapt sufficiently to the adjacent regenerating environment which has plenty of heliophyte species.
Many field studies (Green and Minkowski,1977; Johnson , 1980; Menon, 1993; Ramachandran and Joseph , 1997; Joseph and Ramachandran 1998) have stressed the importance of conserving the Cullenia dominant evergreen forests,as these monkeys largely depend upon the species of their survival . However,it has been reported that they can also thrive in a low altitude evergreen forest that does not have much of a Cullenia population(Kumar 1987). As the present distribution of lion –tailed macaque in Silent Valley National Park and adjacent areas is confined exclusively to the cullenia dominant evergreen forests, the conservation of these areas is of the utmost importance.

Ranging behavior
The information on the ranging behaviour of lion –tailed macaque comes from two years of observations (1994-1996) of the main study troop inhabiting  the Neelikal section of the national park. The movements of the macaques were limited during the study to an area of 2.4km2 and were directly related to the distribution of specific resources or sites within that area. The entire troop of macaques normally assembled around nightfall to roost in tree tops in the southern sector of their home range, where the density of their favorite food species like Cullenia exarillata, Palquium ellipticum, Drypetes elata and Ficus spp. were higher compared to the other regions. After some activity  near the roosting site in the earlier part of the morning hours, the troop would depart either as a whole or after forming sub groups and head towards specific food resources available according to the seasons. In some instances the individuals might stay near the sleeping  site when the weather was relatively poor. The average distance traveled per day in the first year of the study was 2.28km and 2.68km in the succeeding year. The macaques used to take a  circuitous route while ranging  in the habitat which took into account a variety of factors  such as the presence of neighboring troop, intermediate feeding location , day time resting site, etc.
Green and Minikowski (1977) estimated the home range of the lion –tailed macaque as 5 km² in Ashambu hills with its many cardamom plantations , whereas Kumar (1987) estimated a home range size of 1 km² in the fragmented forests of Varagaliyar in Indira Gandhi Wildlife Sanctuary in Tamil Nadu State . The greater  home range size in the former study was due to the absence of multi layer forests in the cardamom plantation where most of lion –tailed macaque macaque troops exited. Due to the scarcity of resources under the multilayer canopy condition, the troops were forced to range more widely. The home range estimates of 2.40 km² during the present study could  be due to the greater troop size and contiguity of the forest when compared to the Varagaliyar troop.
In the undisturbed habitats like Silent Valley National Park, the individuals were observed descending to the ground only five times out of the 12,134 scan records, whereas in distributed and degraded habitats they spend a substantial part of the daylight hours on the ground level( Menon, 1993; Singh et.al., 1999). This mostly arboreal macaque is probably safer in the upper canopy than on the ground where the predatory pressure is greater with the presence of carnivores like wild dog, leopard and tiger.
Factors affecting conservation of lion –tailed macaque
Although the conditions are quite ideal for the lion –tailed macaque inside the territorial boundaries of the national park, the situation is not safe in the adjacent peripheral areas. During the study period, Muduga tribals trapped nine lion –tailed macaque from a troop in habiting the Panthanthod area of the Attapady forests adjacent to the national park. This  area is very rich in the Cullenia exarillata - Palaquium ellipticum tree association. As the Tattengalam caradamom estate lies in the east- west axis in the Panthanthod area, there is a break  in canopy continuity except for a small strip of forest between  the estate and the road from Mukkali to Silent Valley. This area is degraded due to previous fires and it will require intensive management and protection to get it back to its former pristine nature. Conservation of Silent Valley National Park  and consolidation of the reserve is of prime importance.

MANAGEMENT STATERGIES