FLORA AND FAUNA

The following article was written by Peter Bright, a biologist and naturalist who was previously a colleague of Rangala House owner Anthony Newman, both at Clifton College (Bristol) and at Colombo International School (Kandy). His knowledge of the flora and fauna of Sri Lanka is extensive and he has particular experience of the Knuckles region.

INTRODUCTION

Tree frogs outside Rangala HouseSri Lanka has a wide variety of habitats each with a characteristic flora and fauna. The island divides, most significantly, into wet and dry zones. The dry zone gets the North East monsoon rains between November and January and then has a nine month period that is almost entirely dry. The vegetation reflects this and the trees may lose their leaves entirely or have small dry tolerant ones. The wet zone gets both monsoons, i.e. between November and January and then between May and September. It also gets inter monsoon rains including thunder storms in between these times, particularly in late March and April. There is, therefore, rarely more than a month that is very dry e.g. February.

The next most significant factor is the altitude. There is a coastal plain where the sea influences the vegetation and which is often dominated by coconut. There is then a lowland plain all the way around the Island. The high lands in the centre are in two main blocks divided by the Mahaweli river valley. Much the largest is around Nuwara Eliya and Bandarawela and includes Horton Plains. Much of this is between 5.000 and 7 000 feet (1600m to 2000m). The second block is the Knuckles Region which isn’t quite so high but ranges from 3000 and 5000 feet (1000m up to 1500m). Most of this highland is in the wet zone except the extreme North eastern slopes which are in the rain shadow of the South West monsoon and are thus dry zone.

The temperatures around the coast may have maxima of 38-40°C and minima of 25°C. In Nuwara Eliya, which is regularly the coolest place in Sri Lanka, maxima of 28°C and minima as low as 12°C can be expected. The temperatures vary with the time of year with March and September being the hottest and December and January being the coolest. Humidity is nearly always high. Being only 7 to 8°N of the equator the sun is always strong but passes to the North at midday in the Northern summer and to the South at mid day in the Northern winter.

The natural vegetation is almost entirely determined by this mix of rainfall and altitude and so, therefore, are the animals and birds that go with it.

However, there is very little natural vegetation left in the lowland wet zone with the land dominated by rice cultivation in paddy fields in the flatter parts and garden plots with coconut, jak ,mango, banana and a variety of other fruiting trees in between. Most depend on natural rainfall for water. The largest remaining block of Tropical Rainforest (the natural vegetation of the wet zone) is in Sinharaja. It is in the natural vegetation of the wet zone that leeches abound so that some thought needs to be taken about them. They do not carry any disease but their anticoagulant saliva means that bleeding can be profuse. Leech socks really do work (but the leeches can climb above them!) In this forest are many endemic plants, trees, birds and insects which have developed here isolated from the rainforests of South East Asia.

The dry zone has many national parks and other protected areas that stretch in an arc from Wilpattu in the North West through Minneriya, Wasgammuwa, Gal Oya down to Yala in the South East. Here much of the characteristic wildlife of Sri Lanka can be seen. Elephant, leopard, sloth bear, crocodile, wild boar, spotted deer and sambhur. Many of the birds of this region are shared with Southern India and so there are very few endemics. The highlands have lost much of their natural vegetation and have become tea plantations. The tea grown above 1000m is the most sought after and is the basis of the large export trade in this commodity. The tea highlands are carpeted in tea bushes. These are interspersed with trees which are said to act as wind breaks, provide humus from leaf fall, nitrates from their root nodules as they are often legumes, or a source of wood for the drying process that the tea needs after it has been picked.

It is particularly in the Knuckles region that a lot of natural forest remains, forming the Knuckles National Park. Here there is another suite of endemic plants, trees and birds isolated from other highland regions in India by the dry zone forests at low altitude. It is in this region that Rangala House is located.

AROUND RANGALA HOUSE

Water lilies at Rangala HouseThe house is surrounded by tea estates and there is a tea factory a mile or so further up the road. The tea fields have more or less naturally forested patches either above them as water catchment protection, or amongst them in river valleys. It is in these patches that the interesting birds can usually be found. The birds often move about in mixed species flocks called here “bird waves”. These same flocks may pass through the Rangala House garden when moving from patch to patch.

The endemic Toque monkey is also here though it is widely distributed across most of the Island. The dry zone monkey is the black faced grey langur and the forest (both dry and wet zone) monkey is the purple face leaf monkey. In the highlands it is known as the bear monkey from its shaggy fur. Its characteristic throaty calls are a feature particularly of the native forested parts of the high country.

Towards Corbett’s Gap there is some of the highest land in the Knuckles and the native vegetation becomes properly montane forest. Its low growing dark green shiny leaved trees grow tightly packed together, protecting them against the strong winds and strong sunshine. Many Sri Lankan trees have red young leaves and shoots which is said to protect the developing chloroplasts from the strong sunshine until the leaves mature and become the usual dark green.

The characteristic birds of this area (see list below) include the nectar feeders on the flowering trees – e.g. the Sri Lanka hanging parrot, the purple and the long billed sunbirds, the birds of the trees feeding on a variety of fruits and insects – e.g.the parakeets, the barbets, the leaf birds, flower peckers, hill mynahs, minivets, bulbuls and the white-eyes. Out and out insect eaters include the brown shrike, white bellied drongo and the bar winged flycatcher shrike. Then, on the tree trunks, there is the brilliantly coloured red-backed woodpecker with its characteristically loud laughing call; and in the more open spaces, feeding from perches, the white-fronted kingfisher. On the ground or in hedges and tall grasses, the munias, the tailor bird (of rikki tikki tavi fame!), and in the Northern winter the gorgeous Indian Pitta can all be seen. In the sky are the swallows (Sri Lanka swallow and hill swallow), the swifts (little swift with house martin colours with white rump, the palm swift, brown with narrow wings and deeply forked tail, and the Indian swiftlet with notched tail which is the bird that makes the nest of bird’s nest soup). Then above them are the raptors – the largest is the black eagle with characteristic silhouette, and the serpent eagle whose characteristic mewing cries are a feature of the Rangala House verandah!

Migrants: There are many bird species that winter in Sri Lanka and so are found only in the months between October and March. Several of them are real treasures but hard to find. The Indian pitta, the Indian blue robin, the barn swallow – here known as the East Asian swallow, the forest wagtail with double breast bands. There are others that move around, maybe following the rains like the Cattle Egrets, and the various cuckoos.

Birds familiar to European bird watchers include the grey wagtail, the common sandpiper, the barn swallow, the great tit – here also known as the grey tit as it has none of the yellow colour of the European forms.

RANGALA HOUSE BIRD LIST

Birds shown in italics are endemic.

The following birds have been identified recently from the verandah at Rangala House:

In addition, the following birds have been identified within walking distance of Rangala House: