Searching for the slender loris: Bengaluru’s diminutive tree crawler
The slender loris continues to survive in isolated green pockets. But how has urbanization and the loss of habitat affected this ancient primate?
In the early hours of a dark, chilly January night, Varsha Bhaskaran is shining a flashlight into the dense wooded thickets of an old educational institute in Bengaluru. Bhaskaran is on the lookout for a long-time inhabitant of the Garden City—the slender loris, with its distinct orange eye-shine.
“If you want to see the loris, the loris has to see you first as it is really small, grey, and, against a dark background, difficult to spot," says Bhaskaran. When she did see the orange glow, Bhaskaran only caught a fleeting glimpse of the loris. It took her 5 minutes to spot it again on the same tree.
Once you spot a slender loris, it is difficult to take your eyes off it. It has big hypnotic eyes in an enlarged head atop a small body. With tiny limbs and no tail, it resembles a perpetually startled extraterrestrial out of a Steven Spielberg movie. Only prettier—it would fit into your cupped palms.
Though closely related to humans, it is an ancient primate that evolved long before most other monkeys. Over time, however, as larger monkeys evolved to be active during the day, the loris, to avoid competition for food and space, took to being active at night. Those disc-like eyes allow it to hunt insects in pitch darkness.
These ancestral monkeys are closely related to others of their ilk, like the bushbabies of Africa, lemurs of Madagascar and slow lorises found across the North-East, Bangladesh and South-East Asia. The slender loris, though, is restricted to the forests of southern India and Sri Lanka.
It can be found in the wet evergreen forests of Kerala, the thorny scrub of the Eastern Ghats in Tamil Nadu and Andhra Pradesh as well as in mango and tamarind orchards. Once found all across Bengaluru, it now survives in small, isolated green pockets of the city, for as Bengaluru—once a laid-back town—has burgeoned into a cramped, bustling metro, its tree cover has dwindled, from 68% in 1973 to 25% in 2012, according to a report on the website Researchmatters.in.
This loss of green spaces has hit the slender loris hard. “Bangalore used to support a healthy population of slender loris before but their numbers have decreased due to urbanization and industries," says Bhaskaran, who is pursuing a master’s degree from The Energy and Resources Institute, New Delhi, but is studying the slender loris as part of her dissertation assignment under the Urban Slender Loris Project (USLP). The project brings together citizens from different walks of life and professional scientists in an attempt to document the urban biodiversity of Bengaluru, with the slender loris as its focus species.
As Bengaluru’s urban sprawl spread from an area of 70 sq. km in 1949 to nearly 750 sq. km today, and the city emerged as a centre for the software and manufacturing industries, the green areas took a beating. The construction of a web of roads, flyovers and the metro has further fragmented the tree line, disrupting the habitat of the loris. “So the populations of slender loris are concentrated in certain areas and are not as widespread as they used to be earlier," says Bhaskaran.
Fragmentation and loss of habitat is the primary threat to the loris’ survival in the city. For although the loris is a primate, it can’t jump from one branch to another like a monkey. It lives in trees and walks through woodlands. In fact, it moves slowly—with three limbs holding on and the fourth inching it forward—through the canopy. It uses thick, thorny shrubs like zizyphus and acacia to move and climbers like bougainvillea to rest and hide from predators, such as kites, crows and jungle cats, during the day.
“Canopy continuity is very important for the loris; once that is lost, they find it difficult to move from tree to tree," says Sindhu Radhakrishna, a primatologist at the National Institute of Advanced Studies, Bengaluru. Although Radhakrishna has noted instances of the loris coming down from trees to cross roads, they’re at risk of attacks from predators and of becoming roadkill, for they cannot navigate quickly on all fours or jump sideways. “Loss of forest cover puts them in danger and brings down their numbers," she says.
It hits their diet too. As trees are chopped, the insects, a major part of their diet, disappear. To compensate, the loris switches to fruits. But tree loss hits these too. This affects their ability to reproduce or nurse young ones—ultimately leading to a reduction in population.
“We really do not know what would be the fate of these animals in the city unless we continue to provide some habitats for them," says Kaberi Kar Gupta, visiting research scientist, North Carolina Museum of Natural Science, US, who also heads the USLP. Earlier, they recorded a few hot spots in the city and the kind of vegetation there. They continue to record areas where the loris is found as well as potential patches.
In the not-too-distant past, numerous educational campuses, large spaces demarcated for defence and government establishments, and huge recreational parks developed by the British ensured that greenery clothed the city. Such vast intact green spaces were fantastic habitats for the loris. Now, they are forced to find refuge in the grounds of a few research institutes and public parks.
But perhaps all is not lost. With some imagination in planning developmental projects, the remaining veins of hedge trees and isolated green patches can be developed into corridors connecting extant green spaces. This will not only serve the loris but also butterflies and birds.
The enigmatic slender loris can be a flagship icon of Bengaluru’s urban natural heritage. Restoring the city’s green glory would not only help the loris survive but also make the city more liveable for its people.