Biodiversity in Sri Lanka

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Green Pit Viper

The biodiversity of a country or geographical region is usually considered to be the degree of variation present in its resident life forms and ecosystems. A visit to Sri Lanka presents a unique opportunity in this context, having been listed amongst the top 25 global hotspots for biodiversity. The ecological watchdog organization Conservation International has indicated that there are over 3000 endemic plant species, 140 endemic species of amphibians, 14 endemic species of mammals and 10 endemic species of birds in Sri Lanka. It is the home of some truly amazing vertebrate creatures ranging from the one ounce Hanging Parrot (Loriculus beryllinus) which nests in the central highlands, to the 200-ton Blue Whale (Balaenoptera musculus) – the world’s largest mammal – which freely roams the warm tropical waters off the island’s southern coast.

 

Elephant at Yala National Park

Elephant at Yala National Park

Sri Lanka has fascinated naturalists of global repute for many centuries. The German physicist and botanist Paul Hermann arrived in Ceylon (as Sri Lanka was known in those days) in 1672 and spent five years studying its fauna and flora and collecting specimens. Hermann moved back to the University of Leiden in 1679 and set up what was considered the finest botanical garden in Europe at the time. His seminal work on Sri Lankan biodiversity was published under the title ‘Musaeum Zeylanicum’ in 1717. It was Hermann’s collection that inspired the legendary Swedish naturalist Carl Linnaeus, who is regarded as the father of modern ecology and taxonomy. Linnaeus studied Hermann’s notes and classified much of the Ceylonese fauna and flora. It was Linnaeus himself who gave scientific names to such strange and wonderful creatures as the bloodshot-eyed Loris or Unahapuluwa (Loris tardigradus). Linnaeus had such an affinity towards Sri Lanka that he even suggested the Elephant’s locality of origin as Zeylonae paludosis or Ceylon.

Carl Peter Thunberg, an apostle of Linnaeus, disembarked in Sri Lanka in 1777 as part of his global voyage of biological discovery. Thunberg travelled around the island to cities such as Galle and collected many thousand specimens of animals and plants, and delivered them to the Royal Swedish Academy of Sciences for classification. In the following century Ernst Haeckel, the German biologist and philosopher of great repute, wrote an entire thesis on Ceylonese flora and fauna, as well as its people and manners, titled ‘A Visit to Ceylon’ (published in 1881). The early 20th century saw many illustrious ‘ecotourists’ cum fellows of the Royal Society visit Sri Lanka, like D. M. S. Watson (zoologist), J.B.S. Haldane (geneticist and evolutionary biologist) and Julian Huxley (public intellectual). They all showed a keen interest in the island’s natural history and made reference to Sri Lanka in their work.

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Little Green Bee-Eaters

One likely reason why Sri Lanka has such a rich biodiversity is the island’s markedly varied climatic zones that coexist in close quarters; ranging from arid, sunny beaches in the south-east to steamy tropical rainforests near the south-western coast to soothing temperate climes in the central hills. Although a small tropical island nation of merely 65 thousand square kilometres, the variation in temperature on any given day could be as much as 20o  Celsius. One could set off by train on a hot, muggy morning from the country’s metropolis Colombo with the thermometer reading 30o C, to reach the region known as ‘Little England’ in the hilltop town of Nuwara Eliya by noon, and find the thermometer reading 10o C. Darwinian adaptation is displayed by some early immigrant species to this climatic dispersion. Climatic polymorphism can be observed prominently in Sri Lanka’s avifauna, where a given species of bird has a range of subspecies adapted to the island’s different climes. The Red-vented Bulbul, which is a common inhabitant of the low country plains, is a good example; a likely upcountry deviant is the fluffy Yellow-eared Bulbul with its protective tuffs of feathers near its ears. The chubby Dusky-blue Flycatcher of the upper hill country is another candidate for possible climatic dimorphism, and appears to be a close adaptive deviant of the common Blue Flycatcher found in the wet lowlands.

The flagship attraction for wildlife enthusiasts visiting any country are its ‘big five game’, or rather its top five protected species as we ought to call it in this day and age of strict conservation. Sri Lanka boasts of a truly impressive line-up of ‘top five’ sizable creatures that are easily sighted: the Humpback Whale (Megaptera novaeangliae), the Sri Lankan Elephant (Elephas maximus maximus), the Sloth Bear (Melursus ursinus inornatus), the Sri Lankan Leopard (Panthera pardus kotiya) and the Sambar (Rusa unicolor unicolor). Furthermore, there are many physically impressive carnivores resident in the island that hunt at the top of their respective food chains such as the Estuarine Crocodile (Crocodylus porosus), the Jackal (Canis aureus naria), the White-bellied Sea Eagle (Haliaeetus leucogaster), the Ceylon Fishing Cat (Prionailurus viverrinus), and the Rock Python (Python molurus).

The diversity of creatures gets more and more as we traverse ‘backwards’ in the evolutionary tree of life. Sri Lanka is known for its perplexingly large number of amphibians and harbours three endemic genera named Adenomus, Nannophrys, and Lankanectes. A new species of frog named Nannophrys naeyakai was discovered in the Monaragala district as recently as 2007. The amphibian history in Sri Lanka is not all hunky-dory however. Sadly, of the world’s 34 amphibian fauna extinct in the last 500 years, 19 were from Sri Lanka. The main reason for their extinction is the loss of habitat to urbanization, and the abundant use of pesticides for agriculture. However there is hope today for the frog, with many ardent conservationists like Rohan Pethiyagoda of the Wildlife Heritage Trust campaigning hard for reforestation. When we come to invertebrate classes such as insects, the species count exceeds a staggering eleven thousand insects. The Sinharaja rainforest is home to such world-renowned insect beauties as the Birdwing butterfly with its massive 6-inch wingspan.

Other interesting and unusual creatures that are worth spotting in Ceylon include the troll-like nocturnal bird called the Sri Lankan Frogmouth (Batrachostomus moniliger), the Rhino Horn Lizard (Ceratophora stoddartii), the rare Indian Chameleon (Chamaeleo zeylanicus), the Grizzled Giant Squirrel (Ratufa macroura), the Tarantula or Divi Makuluwa and of course the strictly nocturnal Loris that we mentioned earlier. Sri Lanka is also home to some unusual plant species such as the insectivorous Pitcher plant (genus Nepenthes). Strange endemic fauna and flora are best sighted in the country’s 22 national parks, which fall into five broad habitat types; mangrove swamps, scrub jungle, tropical rainforest, mountain forest and mountain plains. Each type of habitat is represented by several national parks that exhibit subtle variations in their fauna and flora. plains.

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Pattanangala, Yala National Park

Sri Lanka’s geology is predominantly of a crystalline, igneous nature – granite and its weathered by-product Kabok being the commonest rock – and there unfortunately are very few sedimentary deposits to help palaeontologists trace the evolutionary story of its life through a fossil record. One notable exception though is a large deposit of Marine fossils unearthed at Tabbowa in the Puttalam district, which belongs to the Jurassic and subsequent periods. Jurassic fossils of conifers, cycade and ferns, as well as petrified Conus belonging to the Miocene period are fairly common at Tabbowa.

The wildlife of Sri Lanka is richly manifest in its folklore. One curious exposition of wildlife in Lankan folklore is the tale of the Ulama or ‘Devil Bird’, infamous in the early part of the 20th century and investigated by the Ceylonese Burgher physician and writer Dr. R.L. Spittle. Thought to make visitations to remote human encampments near the wilderness, the shrill catlike cry of the Ulama was said to be a portent for death in the household. Casual references to the Ulama by naive conversationalists during late evenings was said to curdle the blood of the better-knowing, who had ‘seen’ the effects of its cries. As a result, the use of the word ‘Ulama’ was banished from polite society for much of the 20th century. In truth, the likely candidate for the Ulama is the Forest Eagle-Owl (Bubo nipalensis), a large carnivorous bird of nocturnal hunting habits possessing a loud catlike cry. Any deaths associated with its cry are certain to be coincidental or fabrications, as Dr. Spittle and later investigators concluded. Another prominent wild animal in ancient Ceylonese folklore is the Cobra (naja naja), featuring variously as a noble guardian of the Buddha during his pre-enlightenment meditations, or as a spiritual visitation by one’s sainted mother. The indigenous population of yore treated all wild animals and plants with great respect, mainly due to the strong Buddhist belief in reincarnation. In the pre-Buddhist Anuradhapura Period, killing was fairly common for food, but rare for sport except among certain Royal Families.

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Crested Hawk-eagle

Whether you are an enthusiast of biodiversity or just a tourist with an eye for nature and a taste for having a good time, a visit to Sri Lanka is guaranteed to impress. The country has a wide network of classy tourist accommodation and accompaniments to satisfy the discerning traveller. The unfailing monsoon rainfall in recent years has brought about a visible increase in the overall biomass in the country’s national parks as compared with that of the 1980s and 1990s, and there is an explosion in the populations of large animals like Deer, Leopard and Bear. The year 2014 holds plenty of promise for the amateur naturalist visiting this tropical island that once was known as ‘The Pearl of the Indian Ocean’.

Story | Ruwan Rajapakse
Photography | Danushka Senadheera (Green Pit Viper), Ruwan Rajapakse (Green Bee-Eaters, Patanangala, Crested Hawk-Eagle)

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