RESEARCH PAPER Diversity, Abundance and Threats Of
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NeBIO An international journal of environment and biodiversity Vol. 8, No. 1, March 2017, 6 - 15 ISSN 2278-2281(Online Version) ☼ www.nebio.info I www.neceer.org.in RESEARCH PAPER Diversity, abundance and threats of vertebrate fauna in selected areas of Kammalakkulama tank at Mihintale, Sri Lanka H. K. S. de Zoysa1*and T. V. Sundarabarathy2 1Department of Physical Sciences, Faculty of Applied Sciences, Rajarata University of Sri Lanka, Mihintale, Sri Lanka 2 Department of Biological Sciences, Faculty of Applied Sciences, Rajarata University of Sri Lanka, Mihintale, Sri Lanka ABSTRACT This Study was conducted in Kammalakkulama tank, a freshwater ecosystem and sampling was done twice per week. Random sampling, quadrate sampling, line transect, point count, dung counting, footprints counting and opportunistic observation methods were used to determine the diversity of vertebrate fauna and calculated Shannon-Weiner Diversity index (Hʼ), Simpson Index (D), Pielou’s J (Evenness) (E), Margalef’s Diversity Index (D . A total 125 vertebrates were recorded including 21 (16.8%) fish species, belongs to 15 H mg genera, 9 families and 3 endemic species, 7 (5.6%) amphibians species, belongs to 6 genera, 3 families and 1 endemic species, 14 (11.2%) species of reptiles, belongs to 9 genera, 7 families and 5 endemic species including 4 snakes, 2 lizards, 2 geckoes, 4 skinks, 1 monitor and black turtle and no recorded any venomous reptile species (especially snakes), 71 (56.8%) species both aquatic birds (28) and forest birds (43), belongs to 58 genera, 41 families, 2 endemic species, 3 migrants species and 12 (15.0%) species of mammals, belongs to 12 genera, 10 families at the kammalakkulama tank. KEYWORDS: Diversity, Dry Zone, Freshwater tank, Sri Lanka, Threatened Received 30 October 2016, Accepted 10 January 2017 I *Corresponding Author: [email protected] Introduction ensure sustainable development. A large portion of world’s Sri Lanka is a tropical island located in the Indian Ocean, at the biological diversity coexists with the agro-ecosystem. There is southern tip of Indian peninsular with 65,610 km2 in extent and growing evidence that agro-ecosystem such as irrigation tank and consists of three peneplains; lowland (up to 300 m above sea paddy fields contributed to sustaining regional biodiversity of level), upland (300-900 m above sea level) and highland (> 900 m vertebrates and invertebrates species, since maintain of biological above sea level). According to distribution of rainfall, three major diversity is essential for productive and ecologically sustainable climatic zones are recognized; the dry zone (with an annual agriculture. Irrigated man-made wetland ecosystem can be rainfall < 1900 mm), wet zone (annual rainfall > 2500 mm), and the scientifically defined as agronomically managed ecosystems with intermediate zone (annual rainfall 1900-2500 mm) in the Sri Lanka rich biological diversity (Bambaradeniya et al., 2004). (IUCN Sri Lanka, 2007). Sri Lanka bears many geological similarities with parts of the Indian peninsula (Myers et al., 2000). The seasonal and perennial tanks in Sri Lanka have a most The apparent biotic affinities between the mainland and the important hydrological factor is the change in the water level that island in the Western Ghats–Sri Lanka (Mittermeier et al., 2000; linked to the rainfall pattern. When reservoirs tend to fill up the Myers et al., 2000). The inland vertebrate fauna documented from demand of water for agricultural purposes is also minimal. With Sri Lanka, 30 – 40% are endemic (Bambaradeniya, 2004; IUCN Sri the onset of the dry period, when the inflow is minimal to nil and Lanka, 2007). Species richness of inland vertebral fauna with the consequent demand for cultivation, the water level (Bambaradeniya, 2004); freshwater fish species 91 species (55% begins to decline. As the name implies the perennial reservoirs endemics), Amphibians species 111 (86% endemic), Reptiles retain water throughout the year. The effects of drying of species 209 ( 60% are endemic) (The National Red List of Sri reservoirs during the dry season directly effect to the flora and Lanka, 2012), Birds species 482 (IUCN Sri Lanka, 2007), Residents fauna diversity specially vertebrates. Therefore their abundance is birds 237 and 33 (6 Proposed) endemic and total mammals little bit change and fluctuate during the rain and dry season (De species 124 (17% are endemic) (The National Red List of Sri Silva, 1988). In addition, seasonal reservoirs in Sri Lanka tend to Lanka, 2012). dry up towards the latter part of the drought period (July – September). The present study aims to identify the vertebrate Sri Lanka also has highly diversified freshwater bodies in Dry species present, to calculate the different diversity indices of each zone. There are hundreds of smaller reservoirs scattered vertebrate fauna and to identify the threats on vertebrate fauna in throughout the country in the dry zone area (Fernando, 1990). the selected sites in kammalakkulama tank. In addition, there is a Water resources in the dry zone of Sri Lanka are a pre-requisite to © 2017. NECEER, Imphal. All rights reserved RESEARCH PAPER de Zoysa and Sundarabarathy » Diversity, abundance and threats of vertebrate fauna in Kammalakkulama Tank, Sri Lanka » NeBIO 8(1): 6-15 ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- problem with lacking of data regarding vertebrates diversity at freshwater ecosystems in dry zone in Sri Lanka. Material and Methods Study Area The study area (Fig. 2) is located in the dry zone at Division Secretariat Mihintale, Anuradhapura District and North Central Province, Sri Lanka (8°21'2.02"N & 80°28'24.96"E). The major land use types of the area are dry zone forest (57.1% or 26,345 ha) and scrubland (10% or 4621 ha) (Anon, 2006). The natural vegetation of the area is adapted to annual changes, which range from flood to drought. The typical ground cover is scrub forest, interspersed with bushes and cactuses in the driest areas. Figure 1. Sampling Sites at Kammalakkulama Tank. Figure 2. Location of Kammalakkulama Tank. 7 NeBIO I ISSN 2278-2281(Online Version) I www.nebio.info RESEARCH PAPER de Zoysa and Sundarabarathy » Diversity, abundance and threats of vertebrate fauna in Kammalakkulama Tank, Sri Lanka » NeBIO 8(1): 6-15 ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Kammalakkulam tank (about 34.40 ha) categorized under Minor amphibians and reptiles in Site 1 and Site 2. A quadrate with a Perennial tank (<300 ha) and catchment area of 101 ha (Anon, size of 25 m x 25 m marked and five small quadrates each with a 2011) and close to the Puttalam - Anuradhapura – Trincomalee size of as 5 m x 5 m marked inside the main quadrate. Vertebrates Highway (A 12) at North Direction (Fig. 2). The study was were observed inside the small quadrates in both sites (Site 1 and conducted from 06th May 2013 – 06th December 2013 during the Site 2) from 08.00 hr. – 10.00 hr. and 14.00 hr. – 16.00 hr. Line rainy and dry season including the South-West monsoon season, transect L-1 and L-2 (L1/L2 ((Both of L1 and L2 transect))) was Second Inter-monsoon season and beginning of North-east marked on the embankment with a length of 200 m and width of 2 monsoon season in Sri Lanka. When conducting study data m at both side from the middle line was used for amphibians and collection and sampling were done twice per week in a selected reptiles. two sites in kammalakkulama tank. Point count method (Buckland et al., 2001; Sutherland, 2006) was Sampling Sites used for the aquatic birds. Three-point counts were marked as B - Site - 1 is located at Eastern direction of the tank and near to the 1, B - 2 and B - 3 at each point and 15 minutes spent for counting Puttalam – Anuradhapura – Trincomalee Highway (A-12) (Fig.1) of aquatic birds, which done during 06.00 hr. – 08.00 hr. and 16.00 from North direction. The kammalakkulama village’s road goes hr. – 18.00 hr. Forest birds and other birds were counted along the through this site and either side of the road could be seen shrubs Line Transect B. Line Transect was marked with a length of 200 m and grasses (Panicum maximum). In addition, from beside of x width of 20 m in both sides from the middle line and counting of Eastern bank of the tank have paddy fields and at rainy season birds was done along the line transect from 06.00 hr. – 08.00 hr. these paddy fields are subject to flood. B - Line transect (Bibby et and 16.00 hr. – 18.00 hr. al., 2000; Bibby et al., 1985; Buckland et al., 2001; Sutherland, 2006) located in Eastern bank of the tank and this was used for Diurnal and night Observations was used for counting the taking the count of Forest Birds which are not used the Mammals in Site 1, Site 2, and L-1/L-2 – Line Transects. Day time kammalakkulama tank. Along with this transect, both site observations was done in from the 08.00 hr. – 18.00 hr. Power full villagers’ houses and smaller forest area remaining including head lamp and red coloured lamps were used for the night Neem Trees (Azadirachta indica), Tamarind Trees (Tamarindus observation of mammals and was counted from 18.00 hr. – 20 00 indica), Teak Trees (Tectona grandis), Mango Trees (Mangifera hr. Dung counting (Eggert et al., 2003; Krebs et al., 2001) and indica) etc. footprint counting (Sutherland, 2006) methods were used for identification and to ensure the presence of mammals. Site - 2 located in the South-West direction of tank and lies on the Opportunistic observations also were recorded for all vertebrates embankment and South bank of the kammalakkulama tank. The in the Kammalakkkulama tank. vegetation of embankment; in either side consist of huge trees like Kumbuk Tree (Terminalia arjuna), Neem Tree (Azadirachta Data analysis indica), Tamarind (Tamarindus indica), shrubs and grasses Vertebrates diversity Indices (Hʼ, D, D and E ) were calculated mg H (Panicum maximum).