–Text and Images by Anand Krishnan; paintings by J.G. Keulemans from Legge (1880), sourced from Wikimedia Commons.
The island of Sri Lanka is located very close to the Southern tip of India, separated only by the narrow Palk Strait. The two landmasses have been connected and disconnected at various points in the geological history of the Subcontinent, resulting in both significant interchange of flora and fauna, and a marked degree of endemism, particularly in the evergreen forests of India’s Western Ghats and the rainforests of Sri Lanka’s wet zone. Rainfall is an important feature of Sri Lanka’s biogeography, demarcating as it does the island’s environments into the southwestern “Wet Zone”, characterised by, as one might guess, high rainfall and evergreen rainforest environments, a “Dry Zone” containing largely deciduous and seasonal forests (with some evergreen and semi-evergreen forests along rivers), and an intermediate zone. Following a global pattern in the distribution of biodiversity, the wet rainforests harbor the greatest proportion of Sri Lanka’s biodiversity, including most of its endemic forms. Together with the nearly 3000 year cultural history of Sri Lanka, spanning the Kingdom of Anuradhapura, the city of Polonnaruwa and the Kandyan rulers of medieval times, the unique biodiversity of Sri Lanka is a major focus of study by academics, and indeed poses several possibilities to those interested in the distribution of species. On a recent visit to Sri Lanka, I explored some of its unique wet-zone habitats in search of its unique biota, in particular birds, 34 of which are found nowhere else. Legge’s 1880 ‘A History of the Birds of Ceylon’, with its gorgeous paintings by John Gerrard Keulemans, remains to this day a comprehensive and invaluable resource on Sri Lankan birds and their habits. Sri Lanka’s pride in this endemic avifauna is evinced by the fact that six of these birds adorn the country’s currency notes! My trip was enabled via Jetwing Eco, and guided ably by Mr. Mahinda Jayasinghe, who ensured that my short trip ran both smoothly and successfully. The following essay aims to provide an account of this biodiversity, and to place them in context of their known (or presumed) nearest relatives in the Indian Subcontinent.
Sri Lanka’s wet zone habitats encompass both evergreen lowland rainforest, characterized by high humidity, heavy rainfall and the presence of such Asian rainforest staples as bamboo, treeferns, rattans (and leeches!), and the montane cloud forest-grassland mosaics of the Central Highlands (from whence many of the island’s rivers and streams originate), Sri Lanka’s analog to South India’s shola forests. Both regions have experienced significant deforestation over the years, and an extensive protected area system now safeguards these highly biodiverse environments from degradation. The famed Sinharaja Forest Reserve, a UNESCO World Heritage Site, safeguards the largest remaining block of lowland rainforest (protected after a vigorous campaign for its preservation), and is a veritable treasure trove of biodiversity and endemism. One cannot fail to find interesting flora and fauna during a walk in these dense forests, and nearly all of Sri Lanka’s endemic birds occur here. Martin’s Lodge, located very close to the park entrance, is surrounded by beautiful rainforest, and some of the park’s most charismatic inhabitants visit the lodge balcony in search of food. Sinharaja is explored on foot with a local guide, during which one may attempt to locate its famed mixed-species bird waves. These feeding flocks have been the subject of much study over the years, and will keep cropping up during this essay. In addition, Sinharaja is host to a number of rare endemic mammals and reptiles, photos of which appear throughout the essay, although the text focuses mostly on the birds. World-famous for its hordes of leeches, leech socks are a must for any visitor to minimize bloodletting. Once in the forest, the keen ornithologist listens for the sounds of birds, particularly for the calls that signal the formation of a mixed-species flock.
Each mixed-species flock has certain ‘nuclear’ species that are found in almost every flock, and whose calls may serve as signals during the aggregation of species. In Sri Lanka, these species are the charismatic Sri Lanka Crested Drongo and the Orange-billed Babbler. The vocalizations of these species can be heard for considerable distances, as they forage in the mid-story of forest. The presence of ‘feeding guilds’ means that there are interesting birds to be observed at every level throughout the forest, although the sheer number of birds and species can make it quite difficult to spot them all as they range through the trees picking up insects and fruit. The Ashy-Headed Laughingthrush, with its grey head and peculiar cries, shuns the higher heights of the forest, moving rapidly along the dark understory in large flocks. Legge observed that these birds occupied the darkest, dampest recesses of the forest, such that they might be easily missed if not for their ‘spasmodic cries’. Moving up through the midstory, we regularly observed the beautiful Malabar Trogon in flocks, sallying out from a perch to hawk for insects. The Sri Lanka Scimitar-Babbler, a reddish-colored version of its Indian counterpart, issues its distinctive call from about 6-10 feet (or higher) off the ground, often accompanied by noisy, chattering flocks of Dark-fronted Babblers. Moving higher up into the trees, one may espy a cacophony of bulbuls (Yellow-browed, Black and the endemic Black-capped), the distinctive Sri Lankan Flameback Woodpeckers, Velvet-fronted nuthatches, and the endemic Yellow-fronted Barbet, which hops quietly through the canopy, pausing now and then to issue loud monotonous calls from a hidden perch. Like other barbets, the calls of this species are so prominent and incessant that Legge describes them as the ‘chief ornithological characteristic of the Ceylon hills’. Scanning the shaded regions of the canopy, one may spot the rare and endangered Red-faced Malkoha, a bird which, according to Legge, is ‘fond of tall or shady forest with a considerable amount of undergrowth or small jungle’. This spectacular bird moves quietly in small parties, and is difficult to see except when it briefly perches in a small open spot in the canopy. Sinharaja is probably the best place to see this rare bird, which may now number no more than a few thousand. The Sri Lanka Hill Myna and the threatened White-faced Starling perch only at the tops of tallest trees, on exposed branches and rattan fronds. The former’s loud cries and habit of flying across clearings in small parties render it relatively easy to detect (if not see in the dense forest), but the White-faced Starling has a soft, brief cry that is easy to miss, and may perch quietly and inconspicuously for long periods. The presence of a local guide familiar with its calls is thus key to locating this bird within the dense jungle. The tiny Legge’s (or White-throated) Flowerpecker, a fruit-eating bird colored in stunning black, white and yellow, may also be seen accompanying these flocks. This bird is a curious wet-zone relic of Sri Lanka’s forest, most closely resembling a Himalayan species (the Yellow-bellied Flowerpecker) as opposed to any other flowerpecker found in Sri Lanka or Peninsular India, and is thus of much scientific interest (and a cool bird for the birdwatcher to find!). Legge’s flowerpecker is highly active, mobile and difficult to see in the dense jungle, although its call may often be heard; clearings in the jungle are the best place to find it, for the brief periods that a stunning male perches out in the open on a rattan stem.
Forest birds typically take advantage of any feeding opportunities provided to them, and in areas with numbers of human visitors and a marked absence of hunting pressure, they may grow quite bold and accustomed to the presence of people, approaching to within a few feet of the observer. At Martin’s Lodge on the edge of the rainforest, the habit of leaving fruit out on the balcony (as well as the prolific insects attracted to the lights) attract many bulbuls, barbets and doves. The Sri Lanka Grey Hornbill may fly by at close range, and Grizzled Giant Squirrels may be observed in the surrounding trees. The tiny, beautiful Sri Lanka Hanging Parrot is common, although seeing it perched is another matter altogether! The habit of this little bird of raiding toddy palms renders these trees the best place to get a closer look at it, with its curious habit of hanging upside down. The ‘star attraction’ of this area though is undoubtedly the striking blue-and-rufous Sri Lanka Blue Magpie, yet another bird whose closest relatives appear to be Himalayan. These gorgeous birds visit the balcony of the lodge every morning to hawk for insects, enabling close observation of their habits. Blue magpies are also a threatened species; as early as the 1800s, Legge notes that a considerable number were shot for their long tail feathers. They may also be seen visiting the Information Centre further downhill from Sinharaja, along with other animals. On our visit down here, we were privileged to observe a huge water monitor at close range while in search of the elusive Sri Lanka Spurfowl (or ‘haban-kukula’), a member of the pheasant family. While observing the monitor, we were almost unaware of the pair of spurfowl hiding behind a tree root just a few feet away until the male decided to poke his head out! Sri Lanka’s other endemic member of the pheasant family, the Sri Lanka Junglefowl, the national bird of the country, is quite the opposite; pairs have become almost habituated to human presence at Sinharaja, seeking the visitor out along roadside paths (please do not feed them if visiting!). The gorgeous Spot-Winged Thrush, yet another bird that most closely resembles a Himalayan relative (and possibly some African species! The interrelationships of these birds are highly interesting for future study) hops quietly along forest paths, sometimes just a few feet away from the observer, appearing to follow them for some distance along forest paths. I wondered if this was a habit left over from following large mammals through the forests in search of insects they might flush. The related Sri Lanka Scaly Thrush, however, is highly shy and wary of observers, disappearing silently into the forest as soon as it detects human presence. The tiny Brown-capped Babbler, whose song may be heard frequently in lowland forest, also forages frequently alongside forest paths, the telltale rustling of leaf litter betraying the presence of a small party sometimes foraging just a few feet away!
~ To be continued…
(This is Part 1 of a two part series on Sri Lanka)