The Grey Slender Loris of Sri Lanka

Meike Simms

15 Sep 2017

Aiding Research in Sri Lanka

I have had the fortune of spending 5 weeks in Sri Lanka aiding Colombo University in their research of the grey slender loris. The slender loris is a less well known primate and Sri Lanka hosts two species of it; the endemic red slender loris and the grey slender loris. 

Unfortunately, this species, like many in Sri Lanka, is threatened by deforestation for development. Sri Lanka’s civil war spanned 30 years, which halted development. Since its end in 2009 the human population and development has increased, putting pressure on the many species that call this island home. 

Sri Lankan elephants and leopards are now listed as endangered by the IUCN and have lost more than 60% of their natural habitat in 10 years, limiting their habitat to only pocketed National Parks.

It is a similar story with the grey slender loris who are residents of the Sam Popham Arboretum, a very special island of dry zone forest in the cultural triangle of Sri Lanka. Just a 10 minute drive from Dambulla, on the Kandalama and Dambulla road, you will find the quaint little sign for the IFS (Sri Lankan Tree Society) owned arboretum. Enter the gate and you pass Sam Pophams old house, designed by Jeffry Baur. Continue down the path to the main office where you will meet Mr. Jayantha. He is a fantastic host and it is immediately clear his heart and soul lies in the arboretum. Jayantha has conserved and managed the forest for 20 years under the method called the ‘Popham principle’. 

When Sam Popham, an ex-navy man, bought the land, he originally intended to use it to grow mango. As he planted the mango trees he noticed the native saplings that would outcompete them with ease. Intrigued by their adaptations, he decided to use the land as a sanctuary for native species, instead of the invasive species that are often used to grow timber or fruit. It was then that the locals coined method of clearing invasive species to allow native species to grow as the ‘Popham principle’.

Fast forward to today and the forest is a real gem. With quarrying and housing surrounding all sides, it really is a haven for local wildlife. You can notice it in the way the macaques behave compared to macaques seen in the touristy areas of Sri Lanka. They are much more relaxed and are more afraid of humans, rather than trying to steal our cameras or food.

It is the abundance of native trees that allows the slender loris to thrive in the arboretum. The loris are arboreal and feed on fruits, insects and the occasional bird. The project loris team are here to help Colombo University determine if increased development in the surrounding areas has affected their numbers as well as try to film the elusive primate for Wildscreen Exchange.

After settling into the arboretum, team meet Gahan and Padubu, who have been hired by the University of Colombo to research the loris.  Colombo University informs us they are the best men for the job - and they are not wrong! The pair are true wildlife warriors who have researched elephant-human conflict in Sri Lanka and are animal welfare activists. You only need to be on a night walk with them for a short amount of time to witness their tuned in eyes and ears. They point out wildlife far off in the undergrowth like mouse deer, spotted deer and ring-tailed civets.

Never in my years of wildlife research have I had so much success spotting animals than in the arboretum.

Then, as if by magic, Padubu halts the group. He points high up to a tree in the distance. Two red laser like dots glare back at us from the trees. It’s a loris! Padubu shines a white light on the loris so we can all have a look. It is unfazed by the white light and stares at us in wonder. The loris then moves through the trees and within seconds is gone. The speed of the tiny primates is fascinating. Padubu explains to me how difficult it is to identify the loris’ sex from sight alone, so studying the population is made even more difficult. He and Gahan put a plastic tag on the tree with the loris, marked with the time and date it was seen, and mark the GPS location of the tree. They do the same after our next loris sighting.

“We can estimate if a loris is the same individual or not, depending on where they are and at what time. So far, we believe there is a population of 20 still residing here.”

Over the coming weeks, the arboretum offers up awesome loris sightings and we were able to spot at least one loris every night - our record was seven in one night!


The incredible creatures move rapidly through the trees and our infrared camera cannot penetrate large amounts of undergrowth, making capturing the loris on camera very frustrating. It wasn’t until 2 weeks later that we were lucky enough to capture a loris on camera.

The number of loris is important to find out, explains Jayantha, as they used to be a lot more visible and be active in the trees at near head height.  Now they are more elusive and spend more time in the top canopy. Is this due to increased disturbance and reduction of habitat? The quarry blasts almost daily and my research group has to stay clear of a boundary area of the arboretum to avoid any rocks hitting us, displaying how close the Loris are to the disturbance.

One day we were shown around the quarry by a worker there, so we may better understand the situation. Jayantha explains he has the power to close the quarry, as the environmental department from the Government have told him he only needs to make one phone call. However, he does not wish to take the livelihoods of the many people who live and work there. I befriend a worker at the quarry and he waves me towards a path in the trees. He points to the top of the quarry and soon I am climbing up the side of the quarry. Once I reach the top, I am treated to a private view. I immediately see why he loves his job and he seems like a different person at the top, away from all the action below. The view is amazing up here and you can see the whole of the arboretum, including the surrounding encroachment.

The future of the small population of slender loris at the arboretum is uncertain, but what is clear is that they are still residents of the forest, providing hope for their future. My teams valuable research has helped document the loris’ natural behaviour on camera and identify tree species the loris are usually found on. Pabudu is hoping with continued research he will be able to find a suitable area for a wildlife corridor, so the loris can reach other areas of forest and hopefully increase their numbers.

I recommend visiting the arboretum to any visitor of Dambulla, as not only are the Loris amazing, but the diversity of flora and fauna seen during the day is astounding, considering its small size. You can also make a long lasting impact to the tree conservation in the area by planting a tree, which will benefit the loris in the future by providing them with habitat.

I have learnt so much from my stay at the arboretum and I hope the amazing research being carried there will be echoed in the rest of Sri Lanka in the future.


BOOK YOUR SRI LANKA SAFARI

Contact our destination specialist to start planning your journey.

Contact Us

Add your comment

You are being redirected. Click here if this takes longer than a few seconds.