Ian Lockwood

MUSINGS, TRIP ACCOUNTS AND IMAGES FROM SOUTH ASIA

Posts Tagged ‘Nisaetus cirrhatus

Dry Zone in a Biodiversity Hotspot

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A collage of Sri Lanka’s dry zone species and habitats (SE coast near Kumana).

Sri Lanka’s climate zones, split between the wet, intermediate and dry zones each have distinctive qualities and biodiversity. While the wet zone has the highest levels of endemism the dry zone shows close affinity to southern India’s flora and fauna. There are even several slivers of the island with arid climates that are sometimes separated from the dry zone (the Jaffna peninsula, Mannar, Yala etc.). On several trips in the last year, and most importantly the summer during the pandemic, I continued to explore, document and better understand the biodiversity and landscapes of the dry zone.

Although the extent of the dry zone covers nearly two thirds of the island it is not a homogenous landscape and there are significant variations in terrain, forest cover, hydrology and land use in its different parts. The area is characterized by seasonal spells of intense rain (the monsoon) and longer periods with relatively little rain. The North-East (winter) Monsoon, active from October to January, provides most of the seasonal moisture. This June we traversed the three climate zones: we left Colombo in the midst of showers from the South West Monsoon, experienced rain in the intermediate zone near Sigiriya and then had almost all rain-free dry days in Trincomalee, Batticaloa and Arugam Bay.

Panthera pardus kotiya at Wilpattu National park. Leopards are not exclusive to the dry but the large protected areas of Yala, Kumana and Wilpattu offer the best places to encounter them. This juvenile male thrilled our small group with a lengthy encounter in the early morning of a visit in July. Special thanks to Achintha Piumal who alerted us to its presence and got us to the location without disturbing his morning rituals.

Conservation Value of the Dry Zone

The lengthy Western Ghats/Sri Lanka biodiversity hotspot, as demarcated by CEPF, is characterized by India’s west-coast mountainous spine as well as (almost) the entire island of Sri Lanka. It always intrigued me that the Western Ghats portion is made up of mountainous habitats while Sri Lanka’s portion includes significant lowland, plains areas in its dry zone along with its Central Highlands and coastlines. In fact, all of Sri Lanka, with the exception of the Jaffna peninsula, falls under the hotspot boundary. It’s a somewhat arbitrary boundary distinction and meant to give a target area for the governments of India and Sri Lanka to value and protect. The Western Ghats plains areas in the shadow of the ghats have been largely converted to agricultural and other human-dominated landscapes. In contrast Sri Lanka’s lowlands, especially in the dry zone,  still have large areas of natural forest cover and this most likely explains the boundary choices.

The largest protected areas in Sir Lanka, the ones that draw visitors wanting a “safari” experience, are all found in the dry zone. Yala National Park in the south-east draws the largest numbers of visitors. Its north-eastern parts, bisected by the Kumbuk Oya, are protected as Kumana National Park. In the central plains around Dambulla/Sigiriya parks protected as part of irrigation reservoirs such as Minneriya, Kaudulla and Kala Wewa host some of the biggest congregations of Asian elephants in the world. Sri Lanka’s largest national park is Wilpattu located on the Gulf of Mannar and stretching nearly to the center of the island at Anuradhapura. After being contested during the years of fighting, Wilpattu has made a comeback. Classic dry zone mammal species like sloth bears, elephants, grey langur, spotted deer are all found at Wilpattu. I appreciate Wilpattu for its forests. Visitors spend hours traversing mature strands of tropical evergreen forest to get to the open areas and wilus (shallow natural lakes that can either have saline or fresh water) areas with bird and mammal densities. There are many significant species of trees on the drive in. I appreciate the Manilkara hexandra (or palu/palai) that are a favorites species for birds of prey, Malabar Pied Hornbills and occasionally, leopards.

Many of the other large protected areas of Sri Lanka including Wasgamuwa, Gal Oya and Madhura Oya and Somawathiya are all in the dry zone. Satellite imagery shows large tracts of dry zone forest north of Vavuniya in the Vanni. These were areas that were controlled by the LTTE for many years and survived the ravages of war. At this stage few of these are being explored by wildlife enthusiast and birders, as far as I know.

 

Granite rocky outcrops are a feature of many parts of Sri Lanka’s dry zone. The Kudumbigala hermitage on the edge of Kumana National Park has some exquisite rocks that are safe from those blasting and quarrying.

Connections Across the Straits

Ecologists and others familiar with the plains of Tamil Nadu and Sri Lanka’s dry zone have observed the remarkable similarities in climate, soil and geology. It is certainly something I think about every time I fly into Madurai and drive away from this ancient urban settlement. The red soil and occasional patches of thorn forest and sacred Ficus trees, scattered amongst drought-prone fields and granite outcrops, hint at a past that would have looked quite different.

Rom Whitaker, India’s snake man who is based in Tamil Nadu, visited Colombo in 2010 and gave a public talk sponsored by Dilmah Conservation that reminded me of the connection between Sri Lanka and Tamil Nadu. He drew our attention to the fact that Sri Lanka’s dry zone coastal areas were likely representative of what Tamil Nadu’s plains once looked like. Land cover change on the plains of Tamil Nadu, of course, has been happening at an astounding pace in recent decades. However, Rom was hinting at patterns that happened in India much earlier-as in hundreds if not thousands of years ago. Those changes led to a different landscape and perhaps a less-humid climate in plains Tamil Nadu. This topic deserves thorough academic investigation but Rom’s message was conservation- oriented. He was discretely pleading with the Sri Lankan audience to act to protect areas before sand mining, granite blasting, deforestation and other threats destroyed the remarkable magic of the dry zone.

The situation with Sri Lanka’s dry zone is especially remarkable because it historically experienced dramatic land cover change and then recovered. The ancient Sri Lankan hydraulic civilizations that created systems of sophisticated water management and irrigation more than 2300 years ago were all based in the dry zone. The remains of these civilizations and especially their Buddhist sites in places like Ruhunu, Anuradhapura and Polonnaruwa illustrate of the importance of the dry zone in Sri Lanka’s rich cultural history. It was only later, after repeated attacks and the outbreak of malaria, that the Sinhalese kings moved south-west into the wet zone. That migration left much of the dry zone alone and gave the forested areas a chance to recover. Mark Ashton, Nimal & Savitri Gunatilleke and others in fact state that “the early phases of Sri Lanka’s history therefore suggests that nearly all of the forests now in the dry zone are of secondary origin, having re-established over the last 7-8 centuries.” (Ashton et al. p.12)

The idea that the plains of Tamil Nadu might once have been thickly forested in a way similar to Wilpattu is intriguing. The land cover change and the clearing of these Indian forested areas would have happened so long ago that there are few records of the change. Great kingdoms and empires-the Pallavas, Pandians, Cholas and others-rose and fell over several millennia. Presumably the dry evergreen plains forest was cut back to make room for agriculture during these times. The relatively recent (and well documented) British colonial forestry efforts were focused on wooded, hilly  areas like the Anamalais, Nilgiri and Palani Hills. A modern forest map of Tamil Nadu (see TN Forest Department) suggests that almost all forest cover is in the Western and Eastern Ghats rather than the plains and a few mangrove patches. There are relatively small examples of the dry evergreen forest  in Tamil Nadu and there are efforts in Auroville (see link) to protect and propagate this forest type, but nothing on the scale of what is found across the straits in Sri Lanka.

Panthera_pardus_stretch_at_Wilpattu_3a(MR)(07_2)

Panthera pardus stretching at Wilpattu National park. Special thanks to Achintha Piumal who alerted us to its presence and got us to the location without disturbing his morning rituals.

SELECTED REFERENCES

Ashton, Mark et. al. A Field Guide to the Common Trees and Shrubs of Sri Lanka. Colombo: WHT Publications, 1997. Print.

Conservation International. Biodiversity Hotspots. Web.

Critical Ecosystem Partnership Fund. Biodiversity Hotspots. Web. (see link for Western Ghats projects)

Critical Ecosystem Partnership Fund.. Ecosystem Profile: Western Ghats & Sri Lanka Biodiversity Hotspot (Western Ghats Region). May 2007. Web.

De Silva, Asoka T., Ed.  Sri Lanka’s Forests-Nature at Your Service. Colombo: Sri Lanka Association for the Advancement of Science, 2014.

Ministry of Mahaweli Development & Environment. Biodiversity Profile- Sri Lanka Sixth National Report to the Convention on Biological Diversity. May 2019. Web.

Ministry of Mahaweli Development & Environment. National Biodiversity Strategic Action Plan 2016-2022. May 2016. Web.

Sinharaja 2019 Geography IA Field Studies

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Serendib Scops Owl (Otus thilohoffmanni) on the Sinharaja boundary. Spotted with the excellent help of Warsha and the good company of Desline, Luca and Rashmi.

In April this year the unprecedented attacks on churches and hotels shook the stability and relative peace that Sri Lanka has enjoyed in the ten years since the conclusion of the Civil War. One of the minor impacts of the events was the suspension of field trips for almost all schools, including OSC. That meant a delay in the annual field study that I have been running in Sinharaja since 2005. My students were disappointed but they understood the situation and I made plans to conduct the study in the early parts of the 2019-20 school year.

The students in the Class of 2020 IBDP Geography class are a special bunch: they enjoy each other’s company, love to engage in field work (regardless of leeches and wet conditions) and are not fazed by time away from their mobile phones. The group of eight includes class clowns, aspiring activists, experts in GIS, individuals determined to get good grades and several dedicated birdwatchers. There are five Sinhala-speaking individuals who played a key role in the interviews that are at the heart of the data collection.

In September, after receiving the green light to conduct our field work, the class packed up a bus and headed south to Sinharaja. There we spent four days conducting field research in the home gardens on the north-western edge of Sinharaja rainforest. OSC’s logistic coordinator Desline Attanayake provided support in the interviews and fully took part in all aspects of the study. We hired four Sinharaja guides each day and they were essential in leading us through home gardens and helping the students to better understand the area. Some of them like, Chandra (Sri Lanka’s 2nd female guide in Sinharaja) , have been working with OSC groups for more than 10 years and they know our format and aims well. All of the surveys were gathered on foot in rain or shine. We now have a deep and intimate relationship with the area. The Kudawa village and forest on this side of Sinharaja offer ideal conditions for student learning, inquiry and field work on socio-economic, tourist and land-use themes. Martin’s Wijesinghe inimitable Forest Lodge,  was once, again the base of operations. We appreciate the forest access and family-like atmosphere that he extends to our OSC groups.

Nisaetus sp. on the road up from Kudawa to Martin’s Forest Lodge. I’m not 100% sure of the identity of this individual. Most likely a Changeable Hawk Eagle (Nisaetus cirrhatus) but also possibly a juvenile Legge’s Hawk Eagle (Nisaetus kelaarti).

Each of the students explored an individual geographic research question but pooled all of their sub-questions into a single survey that small groups could run. The actual survey of 48 questions could take up to 20-30 minutes with introductions and a look around their properties. The respondents were gracious with their time and several teams were invited to have refreshments. With four different teams going in different directions we collected 55 different interviews. Once again, we collected responses using Survey 123 a GIS-enabled data gathering app that all the students could run off their phones (we also recorded every response on paper). This allows students to map their results and do basic spatial analysis on the findings using ArcGIS, the GIS software package that they are learning to operate.

Moulawella_rain_pan_1a(MR)(09_19)

The view south from Moulawella Peak. I take this composite panorama of Sinharaja rainforest canopy every time I have the privilege of sitting on top of this beautiful mountain. Soon after, the first drops started to fall on us and we headed down.

Another view of the endemic Serendib Scops Owl (Otus thilohoffmanni) on the Sinharaja boundary. Spotted with the excellent help of Warsha and the good company of Desline, Luca and Rashmi.

In addition to conducting the surveys, students got a flavor of being ecotourists in a tropical forest. They walked the different forest trails, encountered birds, snakes and spiders, and soaked their feet in jungle streams. Before returning to Colombo on Saturday we hiked up Moulawella peak to take in the full extent of Sinharaja. It was a challenging adventure and we encountered mid-morning shower that thoroughly soaked the group on the descent. But all members of the team made it up and down safely. A highlight of the trip was having an encounter with the rare and endemic Serendib Scops Owl (Otus thilohoffmanni). It helped round off an exhilarating adventure in geographic learning.

Past Blog Posts on Sinharaja

Geography IA Trip 2007

Geography IA Trip 2008

Geography IA Trip 2009

Geography IA Trip 2012

Geography IA Trip 2013

Geography IA Trip 2014

Geography IA Trip 2015

Geography IA Trip 2016

Geography IA Trip 2017

Geography IA Trip 2018

General Sinharaja Reflections

 

SELECTED REFERENCES

De Silva, Anslem. Amphibians of Sri Lanka: A Photographic Guide to Common Frogs, Toad Caecilians. Published by author, 2009. Print.

De Silva, Anslem and Kanishka Ukuwela. A Naturalist’s Guide to the Reptiles of Sri Lanka. Colombo: Vijitha Yapa Publishing, 2017. Print.

DeZoysa, Neela and Rhyana Raheem. Sinharaja: A Rainforest in Sri Lanka. Colombo: March for Conservation, 1990. Print.

Gunatilleke, C.V.S, et al. Ecology of Sinharaja Rain Forest and the Forest Dynamics Plot in Sri Lanka’s Natural World Heritage Site.Colombo: WHT Publications, 2004. Print.

Harrison, John. A Field Guide to the Birds of Sri Lanka. UK: Oxford University Press, 1999. Print.

Kotagama, Sarath W and Eben Goodale. “The composition and spatial organization of mixed-species flocks in a Sri Lankan rainforest.” Forktail. 2004. Print & Web.

Liyanage, L. P. K. et al. “Assessment of Tourist and Community Perception with Regard to Tourism Sustainability Indicators: A Case Study of Sinharaja World Heritage Rainforest, Sri Lanka.” World Academy of Science, Engineering and Technology International Journal of Social and Business Sciences. Vol 12 No. 7. 2018. Web.

Lockwood, Ian. “Into the Wet: Field Notes From Sri Lanka’s Wet Zone.” Sanctuary Asia. August/September 2007. 3-11. Print. PDF.

Lockwood, Ian. “Montane Biodiversity in the Land of Serendipity.” Sanctuary Asia. July 2010. Print.

Singhalage Darshani, Nadeera Weerasinghe and Gehan de Silva Wijeratne. A Naturalist’s Guide to the Flowers of Sri Lanka. Colombo: Vijitha Yapa Publications, 2018. Print.

Sri Lanka Survey Department. Sheets 80_x & 81_x (1:10,000) 2nd Edition. Colombo: 2017. Maps & Spatial Data.

Warakagoda, Deepal et. al.  Birds of Sri Lanka (Helm Field Guides). London: Helms Guides, 2012. Print.

Wijeyeratne, Gehan de Silva.  Sri Lankan Wildlife (Bradt Guides). Bucks, England: Bradt Travel Ltd. 2007. Print.

Vigallon, S. The Sinharaja Guidebook for Eco-Tourists. Colombo: Stamford Lake Publications, 2007. Print.

 

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