Population Fluctuation of Aquatic Birds in Thattekkad Bird Sanctuary (Kerala) India

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1 RUT Printer and Publisher Online, Open Access Available at ISSN: (Print); ISSN: (Online) Research Article Science Research Reporter, 6(1):12-16, (April ) Population Fluctuation of Aquatic Birds in Thattekkad Bird Sanctuary (Kerala) India Ambily C B, Rajathy S, and Mohandas A School of Environmental Studies, Cochin University of Science and Technology, Kochi , Kerala amblu1985@gmail.com Article Info Received: , Revised: , Accepted: Keywords: Abundance, Aquatic avifauna, Thattekkad Bird Sanctuary (TBS), Water level Fluctuation Abstract Population fluctuations in aquatic avifauna of Thattekkad Bird Sanctuary, Kerala were studied from February 2015 to January Thirty three species belonging to 10 families were recorded. Abundance and status of different species of aquatic birds were prepared. Ardeidae was represented with 11 species, and Alcedinidae and Charadridae with 5 and 4 members respectively. Among the 10 families observed, families such as Rallidae, Leridae, Motacillidae and Anatidae were represented with two species. Jacanidae was represented by only one species, Bronze-winged jacana. Of the 33 species 30 species were observed during the closing time and 28 species were noticed during the opening stage. The total number of birds recorded was 3335 during closing but the number was reduced to 1857 at the opening stage. This reduction may be attributed to the fluctuation in water level. INTRODUCTION depend upon wetland characters such as size, water Wetlands are water systems with marsh or level, quality of water and availability and fen and with water that is static or flowing, fresh or distribution of food resources (Finlayson et al., brackish, the depth of which at low tide is below 1992). Suguthan and Aby (1996) recorded 43 6m. Wetlands support highly valuable pools of species and Shaju and Aby (2008) recorded 46 biodiversity and genetic resources, but species of wetland birds in the Thattekkad Bird unsustainable development is threatening the bio Sanctuary (TBS), which were resident and wealth even causing species extinction. These are migratory. Balasubramanian and Veeramani (2011) fragile ecosystems susceptible to changes even with recorded 45 species of water birds in Thattekkad a little change to the composition of the biotic and Bird Sanctuary. The present study deals with abiotic factors. Wetlands and water birds are changes in aquatic avian fauna of TBS. inseparable elements and support a rich array of water bird communities (Grimmett and Inskipp MATERIALS AND METHODS 2007). Water birds refer to the bird species that Thattekkad Bird Sanctuary(TBS) falls entirely depend on wetlands for a variety of between and 11 0 N latitude and and activities such as foraging, nesting, loafing, and moulting. They are bio-indicators of wetland E longitude. The altitude ranged from 40m ecosystems, because they quickly respond to any to 523m. and TBS is located at Kothamangalam change in vegetation composition and water level Taluk of Ernakulam District, Kerala state, India. fluctuation as compared to other animals (Custer The Sanctuary covers an area of Sq.Km. It is and Osborne 1977). The species density, diversity, almost at the foothills of the Western slopes of the richness and relative abundance of water birds Western Ghats. Thattekkad Bird Sanctuary is having well defined boundaries ISSN: (Online)

2 The reserved Forest of Kuttampuzha and Neriyamangalan Range, and the two rivers Periyar and the Edamalayar border the sanctuary. At the confluence of Periyar and Edamalayar a barrage- Boothathakettu was constructed in 1962 which inundated many low laying areas in the flood plains of these rivers. This inundation created new wetland habitat which were existent in Thattekkad landscape before. In addition to the reservoir created by Boothathankettu barrage, other landscape elements in the sanctuary are moist deciduous forest, teak and mahogany plantations. Innumerable streams traverse various vegetation types throughout the sanctuary. Most of the streams drain either in to Periyar or Edamalayar River. Every year from June to October the shutters (depending upon rain) of the barrage are kept open to allow the free flow of water in to river Periyar, while the shutters are closed from October to June to retain sufficient water for irrigation. The closure of barrage floods the plains of the sanctuary and the level of water gets reduced considerably once the shutters of barrage are opened. The periodic cycle of flooding of plain and subsequent draining leads to ecological variation in the habitat. This, in turn, affects the flora and fauna of the area adversely (Sugathan 1995; 1996; 1999). During these changes, right from the original habitat to the present habitat, a large number of new flora and fauna were introduced or invaded in course of time in to this area making the system entirely different from what had existed earlier. The present study was carried out during February 2015 to January Pre-fixed line transect were identified in each study plots. Birds were observed and recorded by walking slowly along the transect. Birds were identified and counted with the help of binoculars (Nikon 12x o ) and standard field guides (Ali, 1999; Ali and Ripley, 1978). The time of observation was from 8.00 am to 10 am. Eight intensive study sites were selected from the Sanctuary. The sites identified were View Tower, IB-1, IB-2, Manimaruthumchal, Watch Tower, Kolambuthodu, Kadayam and Kootickal. Each sampling locations is distinct from others by vegetation, depth, quality, trophic structure and extent. Based on the data systematic checklist of birds were prepared and categorised into resident(r), local migrant (LM) and migrant (M). An analysis of population variation of birds was carried out. Ambily C B et al., RESULTS AND DISCUSSION The present study resulted in recording of 33 species belonging to 10 families. Among 33 species observed 5species are migrants 17 Species are local migrants and others residents. Ardeidae was represented with 11 species, such as little egret, Median egret, Large egret, Cattle egret, Pond heron, Grey heron, Purple heron, Green heron, Night heron, Black bittern and Chestnut bittern. Alcedinidae and Charadridae families represented 5 and 4 members respectively. Among the 10 families observed, families such as Rallidae, Leridae, Motacillidae and Anatidae were represented with two species. Jacanidae represented only one species, Bronze-winged jacana. Among the eight study sites 3 sites retained water content at minimum level by the presence of manmade bunds. Remaining 5 sites were completely dry and had a stream running along the side/through the middle site at the time of opening. The number of species and the number of birds in the TBS varied during the study period. Of 33 species 30 species were observed during the closing time and 28 species were noticed during the opening stage. The total number of birds recorded was 3335 during closing but the number reduced to 1857 at the opening stage. This reduction may be due to the fluctuation in water level. Water level fluctuations in wetlands are the result of seasonal flooding, tides, and agricultural irrigation or drawdown. The effect of water level fluctuation on water birds varies among groups and seasons. Water level fluctuation, however, may create ecological traps and be detrimental to breeding, brood-rearing, and molting of water birds (Kaminski et al., 2006). This figure showed that fluctuation in the number of aquatic birds belonging to the different families at the two changes of the habitat. From the results it is concluded that the number of individuals in a population increases under favourable environmental condition. Some of them are typical wetland category and prefer perennials water body. These are teals, darter, cormorants, storks. Sandpipers, jacana, egrets, herons and kingfishers prefer shallow water bodies, which are now plenty in the area due to the impoundment of the river. Muhammad and Mohamed (2011) reported that fluctuations in water level influenced the distribution of water birds from total drought to major flooding ISSN: (Online)

3 Science Research Reporter, 6(1):12-16, (April ) Table 1:- Family-wise checklist of aquatic birds observed during the study period FAMILY & COMMON NAME SPECIES NAME STATUS IN TBS* Alcedinidae White-breasted Kingfisher Halcyon smyrnensis R C Common Kingfisher Alcedo atthis R C Blue-eared Kingfisher Alcedo meninting R C Stork-billed Kingfisher Pelargopsis capensis R C Lesser-pied Kingfisher Ceryle rudis LM UC Anatidae Lesser whistling Teal Dendrocygna javanica R C Cotton Teal Nettapus coromandelianus M UC Ciconidae Open-bill storke Anastomus oscitans LM UC Ardeidae Grey heron Ardea cinerea rectirostris LM UC Purple heron Ardea purpurea manilensis LM UC Little green heron Butorides striatus javanicus LM R Pond heron Ardeola grayii grayii R C Cattle egret Bubulcus ibis coromandus LM C Large egret Egretta alba modesta LM UC Median egret Egretta intermedia intermedia LM UC Little egret Egretta garzetta garzetta R/LM C Night heron Nycticorax nycticorax LM R Chestnut bittern Ixobrychus cinnamomeus LM R Black bittern Dupetor flavicollis flavicollis LM R Phalacrocoracidae Large cormorant Phalacrocorax carbo sinensis LM UC ABUND ANCE Little cormorant Phalacrocorax niger R C Darter Anhinga rufa melanogaste LM UC Jacanidae Bronzewinged jacana Metopidius indicus LM R Rallidae White-breasted waterhen Amaurornis phoenicurus phoenicurus R C Common moorhen Gallinule chloropus indica R UC Charadriidae Redwattled lapwing Vanellus indicus indicus R C Wood sandpiper Tringa glareola M R Common sandpiper Tringa hypoleucos M R Common snipe Capella gallinago gallinago M R Laridae Whiskered tern Chlidonias hybrid indica LM UC River tern Sterna aurantia LM UC Motacillidae Large pied wagtail Motacilla maderaspatensis R UC Grey wagtail Motacilla cinerea M UC Ali, S (1999); *Status R- Residant; M Migrant; LM Local Migrant;, Abundance cited here is based on the number of individuals is observed in the field, C- Common, UC- Uncommon, R-Rare. The highest species richness and density of water birds occur in reed beds of aquatic vegetation, where the water level is cm in depth. Determining the population fluctuation of water birds in wetland habitats is highly important to understand the water bird community structures and population status of existing species in the dwelling areas ISSN: (Online)

4 Ambily C B et al., Fig.1: Population Fluctuation of Aquatic birds in Observed Families. The attraction and response of water birds in relation to water level are conspicuous, and reflect the status of habitat at a given time of a particular area. The problem with the waterscape of the area is its instability. Cyclic draining out and storing in of water affects the ecological stability of the area and prevented it to become either an ideal wetland habitat or a forest habitat. Several aquatic birds leave the area during the draining out of water in the reservoir and it prevent the stabilization of the wetland bird species in the area. Robert (2014) reported wetland degradation is a serious problem; it is one that is more subtle and less understood than wetland losses. Degradation can take many forms: Amounts and periodicity of water supplies can be altered, the quality of water flowing into and through a wetland can be modified, the flows of sediments or freshwater to coastal marshes can be reduced, water levels can be stabilized in wetlands that otherwise would undergo water-table fluctuations and wetland vegetation may be altered by harvesting or by introducing exotic species, making it of little or no value to wetlanddependent birds. Sudden or violent changes in the environment or in the biological characteristics of the individual could lead to a decline. Sinha and Chatterjee (1998), reported that different types of waterfowl inhabit various types of wetland showing a great deal of yearly fluctuation in population and concluded that it depends upon both Abiotic and biotic factors. Fluctuation in the population is usually because of the effect of a combination of several factors responsible for their survival, growth, and reproduction. Various studies have indicated that effectively managed wetlands can provide alternative or complementary habitats for water birds and mitigate the adverse effects of wetland loss and degradation. Wetland management requires integrated knowledge related to the entire wetland ecosystem, and ecosystem-based approach is needed to improve the habitat quality of managed wetlands along with considering multiple spatial scales, temporal variability, and trade-off among diverse habitat requirements of different water birds. Acknowledgement This study was financially supported by the Welfare Department, Government of Kerala. The Authors are thankful to the Director, School of Environmental Studies, Cochin University of Science and Technology for continuous encouragement and facilities provided for the study. Special thanks are due to The Principal Chief Conservator of Forest (PCCF), Government of Kerala, for giving the required permission to carry out the study at TBS, and also to Dr.R. Sugathan and Dr. Shaju Thomas for encouragement, timely advice and support. REFERENCES Ali S, Birds of Kerala. The Kerala Forest & Wildlife Departments Thiruvanathapuram. Ali S and Ripley D, A Handbook of the Birds of India and Pakisthan Oxford University press, London, New York. Custer TW and Osborne RG, Wading birds as biological indicators. Long survey, US Fish and Wildlife Service, Washington, DC. Finlayson CM, Hollis G and Davis TJ, Managing Mediterranean wetlands and their Birds, Slimbridge:IWRB. Grimmett R and Inskipp T, Birds of southern India. Om Books International, New delhi, India ISSN: (Online)

5 Science Research Reporter, 6(1):12-16, (April ) Kaminski MR, Baldassarre GA, Pearse AT, Waterbird responses to hydrological management of Wetlands Reserve Program habitats in New York. Wildlife Society Bulletin 34: Muhammad NR And Mohamed Z, Effects of Water Level Fluctuation on Water birds Distribution and Aquatic Vegetation Composition at Natural Wetland Reserve, Peninsular Malaysia; ISRN Ecology. Prasanna SJ, An annotated checklist of aquatic avifauna of Rajura,Godada and Dhanora lakes of Buldhana district of (M.S.) India,Pp Robert E S, Technical Aspects of Wetlands as Bird Habitat, J National Biological Service, Southern Science Center, 700 Cajundome Boulevard,8-12. Shaju T and Aby PV Final report of the minor research project Dr Salim Ali Bird Sanctuary,Thattekkad- Revised, Sinha J, Chatterjee P, Waterfowl population in some wetland in and around Calcatta and How rah using community parameters, envr.. Ecol. 90,16(4): Subramanian M and Veeramani A, 2011.A repid biodiversity assessment of thattekkad bird Sanctuary, Kerala, Pp Sugathan R and Aby PV A review of the birds of Thattekkad Bird sanctuary, Kerala, J. BNHS. 3, Sugathan R, Ecology of Thattekad Bird Sanctuary. Annual Report. Kerala Forest Department(Wildlife) Pp Sugathan R, Ecology of Thattekad Bird Sanctuary. Annual Report. Kerala Forest Department(Wildlife) Pp Sugathan R, Ecology of Thattekad Bird Sanctuary. Final Report. Kerala Forest Department(Wildlife) Pp How to Cite this Article: Ambily C B, Rajathy S and Mohandas A, Population Fluctuation of Aquatic Birds in Thattekkad Bird Sanctuary (Kerala) India. Science Research Reporter, 6(1): ISSN: (Online)