An Assessment of the Status of Biodiversity in the ... - IUCN

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4. Fauna of MadugangaSpecies composition and relative abundance of vertebrate faunaA total of 248 species of vertebrate fauna, belonging to 121 families were recorded fromMaduganga. These included 20 species (8 %) of endemics, while 30 species (12 %) arenationally threatened (IUCN Sri Lanka, 2000). Among the endemic vertebrate species atMaduganga, 70% are nationally threatened. A comparison of the status of vertebrate fauna ofSri Lanka and in the Maduganga wetland is shown in Table 4. The native vertebrate fauna ofMaduganga represents 30% of Sri Lanka’s native inland vertebrate species. This is a significantproportion, when considering the size of this wetland. It is interesting to note that about 42%of the vertebrate species documented during the present survey are new records to theMaduganga wetland. Compared to the survey carried out by the Central EnvironmentalAuthority (CEA, 1997), the present survey enabled to document a higher number of fish andbird species.Table 4A comparison of vertebrate fauna in Sri Lanka and Maduganga wetland.Group Sri Lanka MadugangaFish Freshwater 78 (32E,39T) 70 1 (2E, 2T)Amphibians 58 (38E, 33T) 12 (3E, 4T)Reptiles 155 (81E, 86T) 31 (7E, 11T)Birds 226 + 200 WM (23E,61T) 111 (13 WM, 6E, 7T)Mammals 90 (14E, 34T) 24 (2E, 6T)E - Endemic, T - Threatened (IUCN - SL, 2000), WM - Winter migrant1Fish species - Freshwater, brackish water & marine species.The fish consisted of 70 species belonging to 41 families (Appendix 3). Among them, twospecies are endemic, two are nationally threatened, while 1 species is exotic. The fish includefreshwater forms, brackish water forms, fresh-brackish water forms and marine-brackishmigratory species. The typical freshwater species included Striped Rasbora (Rasboradaniconius), Giant Danio (Danio malabaricus), Horandandiya (Horadandiya atukarali), Barbs(Puntius spp.) and the Walking Catfish (Clarias brachysoma). These were observed only in theuppermost (north-east) reaches of Maduganga where water salinity is comparatively lower, dueto the inflow of freshwater from streams. About one third (23 species) of the fish species inMaduganga consist of typical brackish water forms such as the ambassids (Ambassis spp.),Pony fish (Leiognathus spp.), Mono (Monodactylus argenteus), Target fish (Therapon jabua),Mud skipper (Periopthalmus koelrenteri) and the Milk fish (Chanos chanos).11
The migratory species include both “catadromous” species (species that migrate from fresh tomarine habitats for reproduction) and “anadromous” species (marine species which move intobrackish/fresh water for spawning or to spend their juvenile period). A typical catadromousspecies include the Short-finned Eel (Anguilla bicolor), while anadromous species include theSnappers (Lutjanus spp.), Trevally (Caranx spp.), Silver Beddy (Gerres spp.), Surgeon fish(Acanthurus spp.) and Barracuda (Sphyraena spp.).The amphibians consisted of 12 species belonging to 4 families (Appendix 4), including toads,narrow-mouthed frogs, aquatic frogs and tree frogs. These represent approximately 22% of thetotal amphibian species in the island. Among them, 3 species are endemic, while 5 species arenationally threatened.The reptiles consisted of 31 species belonging to 12 families (Appendix 5), covering 20% ofthe island’s reptilian fauna. These included 19 species of tetrapod reptiles and 12 species ofserpents. Among the total species, 7 are endemic, while 11 are nationally threatened. The WaterMonitor (Varanus salvator) is the most common reptile in Maduganga. Breeding populationsof the two species of crocodiles (Estuarine Crocodile - Crocodylus porosus and Mugger - C.palustris) also occurs in Maduganga. Among the other reptiles, the Indian Python (Pythonmolurus) and the Sri Lanka Kangaroo lizard (Otocryptis weigmanni) are two rare reptiles thatoccur in the remnant patch of lowland rainforest located in the upper reaches of Maduganga.Maduganga harbours a rich avifauna. A total of 111 species belonging to 48 families(Appendix 6) were recorded during the survey, which is much higher than the number recordedby Siriwardena in 1997. These represented approximately 43% of Sri Lanka’s native avifauna.Of the native species, 6 are endemic, while 7 are nationally threatened. About 10% (13species) of the total bird species in Maduganga consisted of winter migrants. The mixture ofvegetation types in the islands and the surrounding mainland area, together with the estuary,has made Maduganga an ideal ecotone for a variety of birds. About 35% of the bird speciesrecorded included those associated with wetland ecosystems, such as herons, egrets,cormorants, teals, waders, kingfishers and terns that feed on aquatic organisms. The islands inthe estuary serve as an ideal roosting site for the above species. A notable feature of the speciescomposition of avifauna in Maduganga is the low occurrence of waders, which may be relatedto the lack of a shoreline and mudflats around the islands and mainland areas, which are thepreferred habitats of wading birds.The mammals of Maduganga consisted of 24 species belonging to 16 families (Appendix 7),representing approximately 26% of the island’s mammalian fauna. Among them, 2 species areendemic, while 6 species are considered nationally threatened. The mainland area ofMaduganga is one of the few refuges of the threatened Hog Deer (Axis porcinus). The smallpatch of remnant lowland rainforest in the upper reaches of Maduganga harbours three speciesof threatened arboreal mammals (Purple-faced Leaf Monkey - Trachypithecus vetulus, GoldenPalm Civet - Paradoxurus zeylonensis and the Slender Loris - Loris tardigradus). The areaalso serves as an important refuge of three carnivorous mammals - the Fishing Cat(Prionailurus viverrinus), Eurasian Otter (Lutra lutra) and the Jackal (Canis aureus). Apart12
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Page 4 and 5: SummaryThe Maduganga estuary and ma
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Page 40 and 41: Appendix 4List of Amphibians record
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Page 44 and 45: Family Species Status RelativeAbund
Page 46 and 47: Appendix 7List of Mammals recorded
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Page 50 and 51: Appendix 10List of terrestrial moll
Page 52 and 53: Pinto, M. L. (1986). Mangroves of S
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