The lion-tailed macaque faces habitat destruction

PALAKKAD: Nelliampathy, the second biggest abode of the most endangered lion-tailed macaque after the famous Silent Valley National Park, is facing destruction of its habitat due to “unregulated plantation activities, fragmentation and conversion of forest land.”

A recent study on “ecology and behaviour of the arboreal mammals of Nelliampathy” found a total of 13 lion-tailed macaque troops with 200 individuals in the area.

Thus it is the second biggest population of one of the most endangered primates. The Silent Valley has 250 members of the species.

Mass campaign

One of the main reasons for preserving the Silent Valley evergreen forests as a National Park — after a decade-long mass campaign led by leading environmentalists and spearheaded by the media against construction of a hydel project — was to protect the habitat of the lion-tailed macaque.

The study by K.K. Ramachandran and R. Suganthasakthivel of the Kerala Forest Research Institute (KFRI) said the total population of the animal in the wild is estimated to be less than 4,000 distributed in the forests of Kerala, Tamil Nadu and Karnataka.

Being habitat specialists, the animals are much restricted to moist forests.

Commercial plantations

Commercial plantations of tea and coffee and hydro-electric dams have resulted in habitat loss and fragmentation of the once contiguous forests, and this has directly affected the population dynamics of the primates.

Limited connectivity

The study found that “nearly two-third of evergreen formation in Nelliampathy plateau was cleared for tea cultivation almost 60 years ago. The remaining natural forests on either side, to the south-west and the north-east, are connected by a mosaic of coffee and cardamom. The land use practices resulting in a mosaic type of vegetation offer limited connectivity through canopy. Coffee plantations are often heavily manipulated to create gaps in canopy for more sunlight, which gives a better yield.”

Alterations in canopy

“Though not drastic as coffee, cardamom plantation is also subjected to alterations in canopy. What has resulted is creation of more gaps in canopy, which has directly affected the arboreal pathways of the lion-tailed macaques, the Nilgiri langurs and the Malabar giant squirrel.”

Moreover, trends in current land use practices are that cardamom plantations are either abandoned or converted into coffee.

Felling practices

The study found that the lion-tailed macaque “had to traverse vast unsuitable patches to find a new food resource and hence more time was spent for finding food. The evergreen forests at some patches in the plateau near coffee and cardamom plantations had undergone two selection felling series. This could have been negatively affecting the feeding behaviour of the macaques with availability of quality food resources-trees selected and removed by the felling practices in the past.

Recent evidence (Sigh et al - 2010) suggests that the macaque males have a bonded and aggressively organised social system unlike what was previously thought.

The present study by the KFRI also shows that macaque troops in Nelliampathy spent a relatively larger time in social interactive activities such as playing, grooming and mating.

Among sub-adult and juvenile males, homosexual behaviour was also observed several times.

The sub-adults males engaged in same sex courtship and mounted several times during the study period.

This particular same sex-mating behaviour of female and male sexes was earlier observed directly in macaque societies with several lines of evidences (Vasey and Jiskoot - 2009), the study said.

Source: The Hindu, 6-9-2011