Bundala Biodiversity Affected
Ornithologists say flamingo species had decreased this year

The Bundala National Park, home to a staggering number of fauna and flora faces a severe environment problem due to irresponsible human actions there according to researchers attached to the World Conservation Union (IUCN).

Some environmentalists said Bundala which was a paradise to the migrant flamingo species is now in danger of losing the attraction. Ornithologists confirmed the presence of flamingo species had decreased this year. However, said it is too soon to spell out the obvious reasons for the decline.

A total of 324 species of vertebrates were recorded from the Bundala National Park, of which 11 species are endemic, while 29 species are nationally threatened.

The vertebrates include 32 species of fish, 15 species of amphibians, 48 species of reptiles, about 200 species of birds, and 32 species of mammals. Among the invertebrates there are 52 species of colourful butterflies.

A total of 32 species of fish were recorded from the lagoons, tanks and streams of Bundala. These include salt water dispersants (Short-fined Eel - Anguilla bicolor), marine forms (Naked-head Glass Perchlet - Ambassis gymnocephalus), brackish water forms (Milk fish - Chanos chanos) and freshwater forms ( Murrel - Channa striata). The Deep Body Silverbiddy (Gerres abreviatus), Otomebora Mullet (Liza melinoptera) and the exotic Mozambique Tilapia (Oreochromis mossambicus) are species that are abundant in the lagoons, while the Dwarf Panchax (Aplocheilus parvus) and BlochÕs Gizzard Shad (Nematalosa nasus) are also among the common species.

Although it is located in the Arid Zone of Sri Lanka, Bundala harbours 15 species of amphibians, which is nearly 25 per cent of the total amphibian species recorded from the entire island. Of these, one species (Athukorale’s Dwarf Toad - Bufo atukoralei) is endemic and threatened as well. The amphibians in Bundala include toads (Common Toad - Bufo melanostictus), narrow-mouthed frogs (Ornate Narrow-mouthed Frog - Microhyla ornatus), common frogs (Skipper Frog - Euphlyctis cyanophlyctis) and tree frogs (Chunam Tree-Frog - Polypedates maculatus).

Most of these species could be observed after a short spell of rain, in roadside areas and water holes, mainly at dusk. The Common Toad (Bufo melanostictus) and the Paddy Field Frog (Limnonectes limnocharis) are species that are very common in Bundala.

A total of 48 species of reptiles were documented from Bundala. These include six endemic species and 13 species nationally threatened. The reptilian fauna of Bundala occupies a wide range of ecological niches, such as marine (Marine Turtles), freshwater (Flapshell Turtle- Lissemys punctata, Mugger Crocodile - Crocodylus palustris), terrestrial (Star Tortoise - Geochelone elegans, Cobra - Naja naja), fossorial (Skinks, Common Blind Snake - Ramphotyphlops braminus) and arboreal (Geckoes, Green Vine Snake - Ahaetulla nasutus) habitats.

Bundala is an ideal place to see the largest reptiles in Sri Lanka; the two species of crocodiles (Crocodylus palustris and C. porosus), the Indian Python (Python molurus) and the Leatherback Turtle (Dermochelys coreaceae). The serpents of Bundala include three highly venomous species in Sri Lanka; the Cobra Naja naja, Russell’s viper Daboia russellii and Saw-scaled Viper Echis carinatus.

The Bundala National Park, including its complex system of wetlands, has made it a paradise for birds, including many species of migratory birds. A total of 200 species of birds have been recorded from the park, over the past three years. These include around 140 residents and 60 winter visitors. Among the resident birds, three species are endemic, while 10 species are nationally threatened. Of the migratory species, 46 are regular migrants, while 12 are occasional visitors or vagrants. The birds of Bundala can be categorized into several groups; Wetland birds (Waders, Gulls and Terns, Ducks, Herons, Egrets and Storks, Flamingoes, Cormorants, Kingfishers, Others), Forest birds (Woodpeckers, Barbets, Pigeons, Raptors), Scrubland birds (Bulbuls, Doves) and Grassland birds (Munias, Prinias, Pipits, Larks and Raptors).

The lagoons, inter-tidal mudflats and salterns provide ideal resting and feeding habitats for numerous species of winter migrants, especially the wading birds. The vast numbers of migratory Stints, Sandpipers, Plovers, Terns, Gulls, Ducks and Flamingo share the wetlands with resident wetland birds such as Herons, Egrets, Pelicans, Cormorants, Teals, Storks and Stilts. The migratory bird species begin to arrive in Bundala by mid-August, with the commencement of the harsh winter season in the Northern hemisphere (Eastern Europe) and continue to stay in Bundala till late April.

The migratory birds that arrive in Bundala mainly come through the North-Eastern coastal migratory route in Sri Lanka. The highlight of Bundala is the migratory Greater Flamingo (Phoenicopterus ruber), which visits in large flocks of over 1000 individuals, from Rann of Kutch, India. However, this year the rate was much less according to ornithologists.

It is important to note that during the last eight years or so; more than 350 flamingoes remained in Bundala year-round, without returning to their breeding grounds. A recent survey has revealed that brackish-water adapted species such as the Greater Flamingo use the irrigation-affected Malala and Embilikala lagoons to a lesser extent, compared to their use of the unaffected Bundala lagoon.

The mammals recorded from Bundala consist of 32 species, including one endemic and five threatened species. These include small mammals (Rats, Mice and Shrews), bats, large herbivores (Elephant, Deer, Sambur), carnivores (Fishing cat, Rusty-spotted cat, Mongoose), scavengers (Jackal, Wild boar) and arboreal (Macaque, Grey Langur) species.

The elephants in the park can be divided into three categories; permanent residents -six to eight individuals, semi-residents 20 to individuals and seasonal migratory herds about 50 to individuals. The migratory herds consist of animals that roam the Yala-Lunugamvehera-Udawalawe-Bundala area. Grey Langur (Semnopithecus entellus), Black-naped Hare (Lepus nigricollis) and Water Buffalo (Bubalus bubalis - mostly feral) are the most commonly seen mammals in Bundala. Among the wild cats in Sri Lanka, the Fishing Cat (Prionailurus viverrina) and the Rusty-spotted Cat (Prionailurus rubiginosus) occur in the park, but these shy animals cannot be observed easily.

The butterflies documented from Bundala consist of 52 species. These include the largest butterfly in Sri Lanka - the Birdwing (Troides darsius), which is an endemic threatened as well. A majority of the butterfly species are found in the scrubland habitat. The most common species in Bundala include three species of the Family Pieridae; Lesser Albatross (Appias paulina), Yellow Orange Tip (Ixias pyrene) and the Small Salmon Arab (Colotis amata). Large aggregations of pierid butterflies can be seen in the mud flats of lagoons, engaged in puddling behavior.

According to the observations made during the IUCN survey led by former IUCN Researcher Dr. Channa Bambaradeniya several human related activities as well as biological factors are posing a threat to the biodiversity associated with the Bundala National Park.

The major threats that affect the biodiversity of Bundala can be summarized under four major categories; habitat deterioration/degradation; direct exploitation of species; prolonged drought and spread of invasive alien species and in adequately planned land-use practices.

The Bundala National Park, covering an area of 6216 hectares, is located about 250 kilometers Southeast of Colombo, in the Hambantota District. The park falls within the Southeastern Arid Zone of Sri Lanka, with a general climate that can be classified as hot and dry. The average annual rainfall for the area is about 1,074 millimeters, with the highest monthly rainfall occurring in November.

The mean annual temperature is about 27.1 ¼ C. Topographically; the park is generally flat with sand dunes bordering the coastline. Three streams, Malala Oya, Embilikala Oya and Kirindi Oya discharge their waters into the park and adjacent areas. The park consists mainly of dry thorny scrubland and lagoons. The shallow brackish water lagoons located within the park includes Koholankala, Malala, Embilikala and Bundala.

The Malala and Embilikala lagoons are interconnected by a natural canal, and receive drainage water from the Badagiriya and Kirindi Oya irrigation systems. Drainage of irrigation water has resulted in chemical and biological changes in the above wetlands.

Pictures by Jagath Kannararachchi

www island.lk

Copyright©Upali Newspapers Limited.

Hosted by


Upali Newspapers Limited, 223, Bloemendhal Road, Colombo 13, Sri Lanka, Tel +940112497500