Dorai and I have been doing field work for about half a year now and in this time we have seen a variety of mammals, birds, insects and fish across a variety of landscapes. Such rich diversity would not be possible if not for the enormous variety of vegetation found in the Palanis. The diverse set of habitats found in the Palanis are not all found together, as different climatic and geological factors favour some species over other. This has led to a very interesting set of vegetation types, largely influenced by elevation, across the Palani’s. In my time in the field I have gradually begun to associate elevation and climate to a particular kind of dominant vegetation.
A tree cactus in different stages of flowering
The lower reaches of the hills are dominated by scrubvegetation composed chiefly of plants like acacia, neem, several kinds of cacti, and other drought and heat resistant species. As we begin to climb the slopes and the temperature falls, there is gradual shift in the vegetation, from scrub to a greener and moisture tropical forest type. The valleys with rivers in their centers usually boast a luxuriant green cover with darker, richer soils, and more species diversity. Vegetation also tends to be more dense in areas with more water.
Grasslands with sharp edged lemon grass (Cymbopogon flexuosus) and the mountain date palm [Phoenix loureiri] extend for kilometers on steep rocky slopes, and are the norm in higher but drier locations, often adjoining rock faces.
In higher elevations, above 1600m, its common to find lower lying [basin] areas with ‘wet grassy marshlands’ that store water. In the higher elevations, it is also common to have ferns with grasses that form beautiful lush green swarths on the hillsides, but they can be a pain to walk through.
All of this variation provides ideal habitat for different species, which our study data attests. For instance, most elephant activity sightings were seen closer to well wooded valleys boasting rivers and streams and they appear to prefer the middle elevations (where temperature and moisture reach a perfect balance) whereas, the black-napped hare was found to be more active on the sparsely wooded, rocky slopes with short tufty grasses and so forth. Pigs were likely to be most active in places where the soil was moist and suitable for burrowing and foraging (Forest patches with thick leaf litter or banks of streams).
1. Dhruv Athreye in February 2018 began a survey of mammals in the Palani Hills and is publishing notes of his field work.