Sunday, May 1, 2011

A Journey to the Land of many lakes


The first weekend of April was a time when the country was griped in cricket fever with the Sri Lankan team qualifying to play the grand final on the 2nd. Yet few of us opted to go “wild” during that weekend and spent two halcyon days roaming in the Wilpattu National Park, which can be literally called as the land of many lakes or villus. The main topographical feature of this park is the presence of large number of flat basin like depressions that are filled with rain water.


Wilpattu is one of the oldest and the largest “modern day” protected area in the country. Its origin can be traced back to 1905, a time when big game animals were being indiscriminately hunted by the “sportsman” of that era. As a mitigation measure, two Game Sanctuaries (Yala in 1900 and Wilpattu five years later) where shooting of wildlife was strictly prohibited were established under the provisions of the Forest Ordinance No.10 of 1885. Steps were also taken to demarcate and reserve “surrounds” to each of these two sanctuaries as “Resident Sportsmen Reserves”.In these areas shooting game animals were permitted under a license during the open season, which lasted for about four months. Government Agents of the area were in charge of protecting these reserves. With the passing of the Fauna and Flora Protection Ordinance in 1937, the Wilpattu Game Reserve became a National Park in 1938.


Presently the park spans for 131, 693 ha spreading in to Puttalam, and Anuradhapura Districts and also include a coastal stretch extending for nearly 50 km. As stated in the administrative report of the 1967-68, admittedly Wilpattu does not show up its animals as easily as Yala National Park, but it has its compensations. Its proximity to Colombo, the varied landscape so full of the right jungle atmosphere, its chain of picturesque villus and its abundant bird life are sufficient to draw more and more visitors. Surveys undertaken in early 1950s revealed that the number of bears and leopard were much higher at Wilpattu than Yala National Park. Leopards were the pride of the park, not so much numerically, but because so often met with by day. In this respect the leopards of Wilpattu were unique, as nowhere else in the world were there such excellent opportunities of viewing leopards, not even in Africa. Presently the situation has revered somewhat, with Yala now becoming the hotspot for leopard viewing while at Wilpattu the number of daytime observations has become less. Although we observed many leopard tracks during our many rounds in the park we didn’t spot the king of our jungle, which was a huge disappointment. Later when I talked to a friend, he told me that they observed five leopards including two cubs during the previous week, indicating that you need luck as well as patience to see them.


Our disappointment was compensated somewhat with a sudden encounter with a five member elephant family at a waterhole near to Talawila bungalow, our home for the weekend. They simply vanished into the gloomy jungle as our vehicle approached. Large resident herds of elephants are rare in the park, but smaller herds have been recorded in the borders of rivers and abandoned tank areas. On both days we also came upon a lonely old bull elephant feeding in the same villu at dusk and dawn.




We managed to observe around 83 species of birds that included several migrants such as the Eurasian Golden Plover. The endemic Sri Lanka Jungle fowl was plentiful while White-rumped Shamas were observed in several occasions. The Shama is a highly territorial bird and the voice of this species is rich and melodious with wide-ranging songs and notes. They are known to imitate the calls of other birds. Our guide’s sharp eyes managed to spot a nesting Indian nightjar which was well camouflaged amongst the sandy vegetation. The jeeps engine disturbed the nightjar exposing two vulnerable eggs to the hot sun. There was no specific nest, but the eggs were just laid on the sandy terrain. As soon as we left, the bird returned to its eggs. The multi-coloured Chestnut Bee-eaters were found basking on the hot sand while species such as Eurasian thick knee, and water associated birds such as Pond herons, Egrets, Little Cormorants and Lesser whistling ducks were very common. Raptors including Brahminy kite, Crested Serpent eagle, Changeable-hawk eagle and White-bellied sea eagle were also encountered in the Park.




The park and its surroundings are also associated with much legend and history. The remnants of the early history of the country, starting from King Vijaya who landed in the Kudrimalai point, and the palace that is believed to be of Kuveni the jungle princess is still in existence. Pomparippu is an archaeological site where sealed urns containing human remains that are dated to pre-Vijayan times have been found. Wilpattu is also a place where new legends are made. For example, an unfortunate incident of an unlawful killing of a sambur by a visiting Nepalese king Mahendra , lead to the total ban in game hunting in early 1960s.


Wilpattu was out of bounds for tourist for more than two decades due to civil war and several unfortunate incidents including the killing of park officials occurred as a result. The park was officially opened to public in late 2009. Few years back, the major threats to the survival of the Park were poaching and droughts that lasted for months and killed many animals. Yet presently haphazard development initiatives have bypassed the previous threats. Two roads are being developed dissecting the protected area and restricting the home ranges of the wildlife, while the incidences of road kills is now mounting up. Even a helipad has been built, but not to rescue the injured wildlife. Sand mining is recorded from the rivers, which in turn will affect the mangrove development and fishery of the Puttalam estuary in the near future. Further land grabbing by affluent people is also being reported. Concerned Environmental activists have filed a case against these illegal activities and are waiting in anticipation for a justifiable court ruling.


In conclusion, it could be said that the Wilpattu National Park should be protected not only because of its multitude of ecosystems that renders services to the survival of humans and animals, or not because of its rich biological and archeological heritage which will provide us with revenue in the form of tourism, but also because our great grand- children need to see the leopard and the elephant which were born to roam free!

Many thanks to Ayanthi , and other team members Madu, Cheryl, Carl, Thushara and our Guide Bandula.


Report and Photos: Nishanthi Perera

Sunday, April 10, 2011

Caterpillars outsmart birds

Yes, they are smart enough to beat birds. Caterpillars that masquerade as twigs to avoid becoming a bird's dinner are actually using clever behavioural strategies to outwit their predators, a new study reveals.

Dr. John Skelhorn, a lecturer in animal behaviour at the University of Exeter, said: "The caterpillars are not just blindly mimicking inedible objects in the environment and hoping for the best, they are actually using complex habitat-selection strategies which exploit predators' hunting behaviour. According to the study, twig mimicking ‘Early Thorn moth’ caterpillars (Selenia dentaria) choose their location to maximise their chances of fooling their predators into thinking they are twigs.

Using domestic chicks (gallus gallus domesticus) as predators of the caterpillars, research showed that caterpillars are more likely to fool birds when twigs are common. In order to exploit birds' behaviour, caterpillars position themselves in locations where twigs are in abundance during the day -- even if they're not good locations for feeding. At night, when the predators cannot hunt by sight, the caterpillars go to rich feeding grounds -- regardless of twig abundance.

Study reveals that chicks are less likely to search for masquerading prey when the object they mimic, in this case twigs, is in abundance.

"The caterpillars make the most of this by selecting habitats where twigs are common during the day, but then abandon them at night, when there are no visually-hunting predators around, in order to go in search of the best feeding grounds."

When the caterpillars were given two options; one with few twigs but plenty of food, and another with more twigs but no food, Caterpillars showed a strong preference for the branch with lots of twigs, offering the best protection from their predators, during the daylight. At night, they opted for the food-rich branch.


Links

John Skelhorn, Hannah M. Rowland, Jon Delf, Michael P. Speed, Graeme D. Ruxton. Density-dependent predation influences the evolution and behavior of masquerading prey. Proceedings of the National Academy of Sciences, 2011; DOI: 10.1073/pnas.1014629108

Saturday, March 12, 2011

FOGSL’s Field visit to the Delft Island


The Field Ornithology Group of Sri Lanka (FOGSL) organized a field tour to Jaffna Peninsula and surrounding islands from 16-20th February 2011, with the participation of 29 of its members. Scheduled for the day three of this trip was a birding tour to Delft Island, locally known as Neduntheevu. It is the largest island (45 km2) in the Palk Strait, located about 40 km off Jaffna peninsula. The only other land mass beyond this is the Kachchativu, which is a barren island positioned at the border of the maritime boundary of Sri Lanka. Delft was named after a city in Holland during the Dutch colonial rule of the country. Unspoilt and untouched by modernity, mainly due to civil unrest during the last 30 odd years, Delft island offers a wide experience to the traveler in the form of birds, wild ponies, old forts, Baobab trees and beautiful beaches.


We boarded the ferry from Kurikadduwan jetty in Punkudutiv island around 8.30 in the morning and reached Delft after more than one hour of sea journey. Several of us opted to sit on the roof of the ferry as the sea was calm as a lake and watched sea gulls and Brahminy kites freely roaming above us. Striated heron was the first bird to be spotted on the nearby shore of the island. It was interesting to watch the antiques of this bird as it got ready to pounce on its prey. These birds are known to place baits such as feathers or leaves on the water surface and pick fish that come to investigate


After having a quick breakfast of ‘sinisambal’ and bread, we found two ‘land masters’ with the assistance of the Navy officials. These small tractors are the main transportation method in Delft and there is single CTB bus operating on scheduled time periods. Thankfully the land is flat, but you have to endure a bumpy ride in the rough terrain under a very hot sun with only Palmyra palms and few dry shrubs for shade. A lonely Indian roller was encountered in an old Dutch church yard near to the navy camp. The beauty of this bird can be only seen during its flight when striking shades of blue mixed with brown can be witnessed. Next bird to be spotted was a Red collared dove, which is related to more commonly seen spotted dove.


The splendor of the dashing wild ponies mesmerized all of us for quite a while. These animals are not native to Sri Lanka, but are a legacy left behind by the colonial rulers including the Portuguese, the Dutch and the British, who bred the animals for transport and work. Some of the animals are branded indicating that their “wild status” is no longer valid. The literature says that during droughts these ponies have a hard time finding enough water to survive and that due to increase in the number of domesticated cattle, there is a competition for food . The remoteness and inaccessibility of the island has provided protection to the wild ponies to live and breed freely up to now, yet in future with the influx of more people, conservation measures will be needed to ensure their survival. Our next stop was a large water hole where an aggregation of waders including Black winged stilts and ducks such as Garganey and Northern Pintail were observed. In the background several wild ponies were quenching their thirst while a young colt was happily playing about.


The giant Baobab tree is another land mark not to be missed. We spent more than fifteen minutes under the shade of the tree, which was a welcoming relief from the very hot sun. Like the Mannar Baobab, this tree was most probably introduced by the Arabian traders. For lunch we purchased biscuits and soft drinks from the small village boutique located near the Kytes tourist court house. Around 5,000 people inhabit the island and they live in small compounds separated from each other by walls built up of dead coral. One has to walk through the small Government Hospitals corridor to have a look at the ruins of the Dutch Fort. Beyond this fort is a cemetery where you will find tomb stones belonging to all religions. During the colonial rule, carrier pigeons were used as the medium of communication between the islands and there still evidence for this in the form of stone cote.


During the few hours we spend at the Delft island, we observed 64 bird species. A multitude of butterfly species are also found in the island and several of us got busy photographing them. Spending five hours was grossly inadequate to fully appreciate the wonders of this delightful small island and its friendly people. Yet due to time constrains, we had to leave it behind with the hope of visiting again, someday soon.


The Department of Wildlife Conservation has identified part of the Delft to be declared as a National Park under the Flora and Fauna Protection Ordinance, mainly to protect to wild ponies. This came as a recommendation under the project titled Integrated Strategic Environment Assessment for the Northern Province. Although good in intention, the technical and financial feasibility of this action is doubtful and a more appropriate action would be to declare the whole island as an Environmental Sensitive Area under the National Environment Act and thereafter develop guidelines to promote sustainable development initiatives within the island. It is also highly relevant to carry out a species and habitat assessment of the island before any such regulations are established.


Bird List

Lesser Whistling-duck

Eurasian Wigeon

Garganey

Little Grebe

Asian Openbill

Black-headed Ibis

Eurasian Spoonbill

Striated Heron

Indian Pond-heron

Cattle Egret

Grey Heron

Great Egret

Intermediate Egret

Little Egret

Spot-billed Pelican

Little Cormorant

Indian Cormorant

Black Kite

Brahminy Kite

White-bellied Sea-eagle

Shikra

White-breasted Waterhen

Black-winged Stilt

Yellow-wattled Lapwing

Red-wattled Lapwing

Common Ringed Plover

Little Ringed Plover

Black-tailed Godwit

Common Redshank

Marsh Sandpiper

Common Greenshank

Wood Sandpiper

Common Sandpiper

Ruddy Turnstone

Little Stint

Curlew Sandpiper

Brown-headed Gull

Gull-billed Tern

Caspian Tern

Whiskered Tern

Rock Pigeon

Eurasian Collared-dove

Spotted Dove

Rose-ringed Parakeet

Asian Koel

Greater Coucal

Asian Palm-swift

Indian Roller

White-throated Kingfisher

Common Kingfisher

Little Green Bee-eater

Blue-tailed Bee-eater

Ashy Woodswallow

Black Drongo

House Crow

Jungle Crow

Barn Swallow

Oriental Skylark

Red-vented Bulbul

Common Myna

Pale-billed Flowerpecker

Purple Sunbird

House Sparrow

Paddyfield Pipit


Report and Photographs: Nishanthi Perera