Report: A Study in Sri Lanka

“Hey. Do you want to write a blog?”

When I saw the message from fellow TKC director Amy Salinas come through, I knew she was about to tell me something great. I immediately said yes without knowing what I was agreeing to. I was excited to receive the email she had forwarded to me. We had received a report from our biologist friend in Sri Lanka, Ranil P. Nanayakkara. Ranil has been working hard in the field and we are happy to share some of his findings with you.

Previously there has not been much effort to understand spider diversity in Sri Lanka. Species descriptions from Sri Lanka are centuries old and were done using museum specimens therefore there isn’t much information about the ecological system.  Ranil and his colleagues set out to better understand the diversity, population, ecology and threats to spiders in Sri Lanka. The goal of this study aspires to form baseline data for future research and to identify spiders which are endangered. Ranil and his colleagues also intend on popularizing mygalomorphs and creating awareness locally about the benefits of spiders in the ecosystem.

The Tarantula Keepers Coalition is proud to be working with Ranil and BEAR (University of Kelaniya / Biodiversity Education And Research). We hope that you find this report as interesting and exciting as we do. And we hope that after reading this, perhaps you will considering donating to our  “Save the Pokies” GoFundMe  to help us assist Ranil in his work and preservation of land.

The GoFundMe is about the Sri Lankan pokies but it’s also about so much more! If we can raise the funds goal of $14,000, we can help Ranil purchase the land he has been studying. This fifteen (15) acres of land is at risk of being cleared very soon. If this small but imperative piece of land is lost, we will never meet the species that Ranil and his colleagues have found in the lowland wet zone of Sri Lanka. Ranil’s research will be irrelevant for a location that ceases to exist.

Here I will briefly summarize the report that Ranil’s submitted to the Tarantula Keepers Coalition. I will also attach the report for anyone who cares to read the original. I urge all keepers to read Ranil’s report. It is extremely interesting and I will not be covering everything he reports on. I have removed locations, as well as photos and maps at Ranil’s request. I would love nothing more than to show you the beautiful spiders that he has found in his studies but Ranil wishes for them to remain a mystery until they are described.

Bio-inventory and Conservation of Mygalomorph Spiders in the Wet Zone of Sri Lanka

Ranil and his colleagues spent more than five-hundred hours surveying and observing locations in the wet zone of Sri Lanka. They collected information on distribution and habitat of different species found in Sri Lanka. A few of the species they observed include: Sason robustum, Indothele lanka, Chilobrachys nitelinus, Plesiophrictus tenuipes, and Poecilotheria ornata, which was the only arboreal species they observed. In addition to these species, our friends recorded several species belonging to Chilobrachys, Plesiophrictus and one species of Poecilotheria. These species are to be described in the near future!

The things Ranil saw…

Spiders were observed in undisturbed locations as well as domesticated locations. Our friends recorded that terrestrial spiders were abundant in the small holder tea plantations, where very little pesticides are used. More females were recorded than males, as females are likely to spend their whole lives in the same burrow unless something happens to cause them to relocate. Males, of course, tend to wander. Ranil and his colleagues suspected that the reports they had received from villagers about spiders venturing in to dwellings were likely to be male specimens. They confirmed two such males.

These terrestrial spiders behaved as expected by displaying a sit-and-wait predatory style. In over 120 hours of focal sampling, just under half (49%) of the spiders’ time was spent sitting at the entrance to their burrows. Just over a quarter (30%) of the time spent completely in their burrows. These spiders were nocturnal and were recorded as being active during the late night/early morning hours. (Interesting observation: the researchers noticed the spiders were less active during full moons! They do feel that more research needs to be done to confirm such findings.) The spiders’ time away from the burrow only accounted for about one-fifth (18%) of the observation. 3% of overall activity was direct feeding observation. Only P. ornata and Indothele species were seen attacking their prey when found within range, and immobilizing it. All other spiders retreated into their burrows after nabbing their prey. 

The threats the spiders face…

Ranil and his colleagues also assessed the spiders’ local threats during this study of the wet zone of Sri Lanka.  The largest threat is, unsurprisingly, human activity. Illegal encroachment by cinnamon and tea growers are threatening local extinction of the spiders since they are not distributed elsewhere. Human developing such as widening of the roads is leaving spiders homeless as the road side banks they prefer are destroyed. What were once large home gardens, plentiful with spiders, are being turned into homes and summer huts as tourism activity increases. Locals often kill spiders they see because they are afraid and do not understand the importance of each and every spider. (Ranil and his team intend to help put an end to villagers killing spiders by providing educational literature to locals so they know what spiders do for their ecosystem.) Much more research is necessary to understand their biology, ecology, and distribution; which will aid in long-term viability of an array of species, which will also be useful in future conservation efforts.

All in all…

World authorities in biological conservation and environment studies have identified the importance of the immediate task of taking inventory of spiders on this planet. Our researchers believe (and we agree!) that spiders, especially mygalomorphs which come from ancient linage, are a crucial part of the structure and function of the many ecosystems of Earth, as they act as biocontrol agents and bioindicators, maintaining the fragile balance. Ranil feels if we lose these ancient species, the whole planet will be overrun by many species of arthropod pests which will destroy crops.

One of my favorite parts of the Ranil’s report….

The closing of Ranil’s report is where I really felt it in my soul. I cannot possibly reword it better than he said himself so I quote:

“The major reason for nature conservation is psychological; the kind of refreshment only the natural environment can give us. The more urban our own day-by-day life becomes, the more crowded our cities, the more tension in everyday life – the greater will be the desire and need to escape to the wilder places that mother nature has given us, where we can gain recreation – re- creation, in the original sense of the word.

“No sooner than later, it is time when we can reserve these natural beauties, there is no other species of taxa in the world that can camouflage themselves or dwell in a tubular dwelling that was developed by them (when it comes to arthropods). Some have even manufactured lids to their dwellings that were constructed utilising the leaf litter from the surrounding environment. Protect nature; protect what Sri Lanka is blessed with. Educate the uneducated and realise what the future holds.”

Please feel free to read all of Ranil’s report below. And if you feel compelled, send a donation, or share Amy’s “Save the Pokies” GoFundMe. We are also holding auctions at The Tarantula Community group this month as we try to reach our goal before April is over.

The Tarantula Keepers Coalition continues to strive to bring you the more current information available as we work towards natural conservation and helping the hobby self-sustain. Stay tuned for blogs about the TKC Population Project, TKC merchandise, updates to our website, a possible TKC expo tour, and lots more!


Ranil's Report 1st Page

One Reply to “Report: A Study in Sri Lanka”

Leave a Reply