The largest surviving tract of undisturbed lowland rainforest in Sri Lanka, Sinharaja is one of the island’s outstanding natural wonders and a biodiverse treasure box of global significance (recognized by its listing as a UNESCO World Heritage Site in 1989). This is the archetypal rainforest as you’ve always imagined it: the air thick with humidity (approaching ninety percent in places) and alive with the incessant noise of birds, cicadas and other invisible creatures; the ground choked with a dense understorey of exotic ferns and snaking lianas wrapped around the base of towering tropical hardwoods, rising towards the forest canopy high overhead.
According to tradition, Sinharaja was formerly a royal reserve (as suggested by its name, meaning “Lion King”). The first attempts to conserve it were made as far back as 1840, when it became property of the British Crown. Logging began in 1971, until being banned in the face of national protests in 1977, when the area was declared a national reserve. Sinharaja is now safely protected under UNESCO auspices, using a system whereby inhabitants of the twenty-odd villages which surround the reserve have the right to limited use of the forest’s resources, including tapping kitul palms for jaggery and collecting rattan for building.
Sinharaja stretches for almost 30km across the wet zone at the southern edges of the hill country, enveloping a series of switchback hills and valleys ranging in altitude from just 300m up to 1170m. To the north and south, the reserve is bounded by two sizeable rivers, the Kalu Ganga and the Gin Ganga, which cut picturesque, waterfall-studded courses through the trees.
A staggering 830 of Sri Lanka’s endemic species of flora and fauna are found in Sinharaja, including myriad birds, reptiles and insects, while no less than sixty percent of the reserve’s trees are endemic too. The reserve’s most common mammal is the purple-faced langur monkey, while you might also encounter three species of squirrel – the dusky-striped jungle squirrel, flame-striped jungle squirrel and western giant squirrel – along with mongooses. Less common, and very rarely sighted, are leopards, rusty spotted cats, fishing-cats and civets. There’s also a rich reptile population, including 21 of Sri Lanka’s 45 endemic species, among them rare snakes and frogs. Many of the reserve’s bountiful population of insects are yet to be classified, although you’re likely to see various colourful spiders and enormous butterflies, while giant millipedes are also common.
Sinharaja has one of Sri Lanka’s richest bird populations: 21 of the country’s 26 endemic species have been recorded here (although some can only be seen in the reserve’s difficult-to-reach eastern fringes). The density of the forest and the fact that its birds largely inhabit the topmost part of the canopy means that actually seeing them can be tricky, especially if entering via the Mederipitiya entrance, where the forest is particularly thick – as ever, a good guide (see Birds of different feathers) is of the essence.
Birds of different feathers
Birds of different feathers
Sinharaja is home to one of the world’s finest examples of a “mixed-species feeding flock”, as it’s technically known, or bird wave, as it’s popularly described: a memorably colourful and noisy rainforest spectacle during which myriad different species can be seen flying and foraging together, “scouring the forest from top to bottom like a giant vacuum cleaner, devouring animals and plant matter in their path” (as Sri Lankan wildlife expert Gehan de Silva Wijeyeratne puts it). From an evolutionary point of view, such collective feeding has clear practical advantages. Safety-in-numbers is one benefit, with members of the bird wave sometimes flocking together to beat off larger predators, while increased feeding efficiency is another.
Different species fly at different levels (ground, rainforest under-storey, canopy, and so on) with mutual benefits – a species feeding in the under-storey, for instance, may disturb insects which fly up and become easy prey for birds in the canopy above, while fruit and seeds dislodged by birds in the canopy may fall to species foraging on the ground.
Bird waves in Sinharaja may consist of over a hundred birds from dozens of different species. The crested drongo is the accepted leader of the pack, calling to other species to begin flocking and also taking responsibility for collective security, sounding an alarm call when danger threatens – at which point the whole flock will suddenly, silently freeze until the drongos give the all-clear. Other species also commonly join in with the wave as it passes through their territory, sometimes offering the remarkable sight of half-a-dozen rare endemics flocking together, while other animals including giant squirrels and mouse deer are also often seen following along.