Journal of Threatened Taxa | www.threatenedtaxa.org | 26 May 2016 | 8(5): 8797–8803
Sheetal Chaudhari-Pachpande 1 & Madhuri K. Pejaver 2
1,2 Department of Zoology,VPM’s B N Bandodkar College of Science affiliated with the University of Mumbai, ‘Jnanadweepa’, College Campus, Chendani Bunder Road, Thane (West), Maharashtra 400601, India
Editor: S. Balachandran, Bombay Natural History Society, Mumbai, India. Date of publication: 26 May 2016 (online & print)
Manuscript details: Ms # 2397 | Received 12 March 2015 | Final received 04 July 2016 | Finally accepted 10 May 2016
Citation: Chaudhari-Pachpande, S. & M.K. Pejaver (2016). A preliminary study on the birds of Thane Creek, Maharashtra, India. Journal of Threatened Taxa 8(5): 8797–8803; 8797-8803
Copyright: © Chaudhari-Pachpande & Pejaver 2016. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.
Conflict of Interest: The authors declare no competing interests.
Acknowledgments: The authors wish to thank the management of B. N. Bandodkar College of Science and Mr.Yashwant Pawar and Namdeo Pawar, local fishermen, for their support and encouragement during research work.
Abstract: Shorebirds also known as waders comprise several adaptations, which enable them to forage on exposed mudflats. The population of birds in any ecosystem shows the environmental quality of the area, pollution level, security and availability of food and habitat. Thane Creek located in Mumbai is one of the unique mangrove ecosystems, maintaining a good population of sediment-dwelling organisms that support a myriad of migratory and non-migratory bird populations. Bird surveys were carried out using the point count method across two different locations at Thane Creek. In total 95 species of birds were recorded during the study and distinguished as per the pattern of their foraging. A healthy diversity of bird species observed indicates the high productivity of the creek.
Keywords: Avifauna, Thane Creek, mudflats, productivity, mangroves, ecosystem
India hosts rich coastal and marine biodiversity in various wetland habitats such as creeks, mangroves, mudflats and salt marshes. Mangroves provide an important habitat for a variety of planktonic and benthic organisms (Nagelkerkan 2008) which attract a myriad of migratory and non-migratory birds that utilize the mangrove ecosystem in varying degrees from feeding, roosting, to breeding (Oswin 2002). The mudflats of the mangrove ecosystems are reported to play a significant role in the conservation of resident birds, migratory and endangered birds (Pawar 2011). Most of the birds that visit mudflats possess long legs and toes, long and sometimes curved bills and are called waders. These adaptations enable the waders to feed in shallow water habitats.
Waders are an important component of the mangrove ecosystem and their occurrence and distribution help to understand the overall picture of the wetland habitat. Most of the birds have specific habitat requirements from season to season, a loss of which may lead to their extinction (Chauhan et al. 2008). Ali & Ripley (1987) reported that India harbors 1,340 bird species which decreased over a decade to 1,237 species (Daniels 1997). Habitat destruction is considered as one of the main reason for such a decrease in bird species population. Presently wetlands are reported as highly fragile ecosystem due to increasing anthropogenic stress. Therefore, this calls for an urgent need for conservation of bird habitats to sustain their population. Wetlands are known to support over 310 species (Kumar et al. (2005). Thane Creek located between Mumbai and Navi Mumbai, inhabits a large diversity of avifauna and is regarded as one of the Important Bird Areas (Islam & Rahmani 2004), as over 205 species of birds are reported from Thane Creek alone (Nitsure 2002).
Bilgrami (1995) stated avifaunal diversity as an essential ecological tool to evaluate the health of different habitats both qualitatively and quantitatively. Wiens (1995) stated that due to the fragmentation of habitats, the viability of the wildlife population is at threat and the same is true for waterbirds and their habitats, the wetlands. According to Kumar et al. (2003, 2005) baseline information is a prerequisite for planning and monitoring management actions for aquatic birds as well as their habitats. Several researchers believed that monitoring of birds of a locality is crucial in predicting the ecological health and productivity of wetlands (Furness & Greenwood 1993; Newton 1995; Ali 1996; Chamberlain et al. 2007; Li et al. 2009; Rotenberry & Wiens 2009). Thane Creek being an important Bird Area, it is necessary to monitor the diversity of birds to predict the health of the ecosystem. The data related to bird diversity at Thane Creek is scarce. Therefore, the present paper depicts the diversity of different species of waders recorded from two stations located at Thane Creek.
Thane Creek is a 26km long inlet from the Arabian Sea towards the landward side near the city of Thane, Mumbai and Navi Mumbai with luxuriant mangrove vegetation and exposed mudflats along its bank (Fig. 1). The area has a moderate humid tropical climate with a maximum temperature of 400C and a minimum temperature of 160C. In spite of several anthropogenic stresses, the mudflats of the Creek fulfil the food requirement for diversity of bird species mainly waders. The mudflats exposed during low tide are used as the foraging grounds by a variety of wading birds mainly a huge flock of lesser flamingo, greater flamingos and a multitude of water birds during the winter season.
One station was selected on each bank of Thane Creek located in close proximity to Bhandup and Airoli villages respectively. Station I selected at Bhandup is located adjacent to the Bhandup Pumping Station which receives waste water from the Mumbai metropolitan area. It also harbors a few abandoned aquaculture ponds built by the local fishing community and serves as the best location for spotting birds for bird watchers. The area supports a rich avifaunal diversity as it provides a mix of different vegetation in small patches that include grasslands, water bodies, mangrove, and mudflats. Station II is situated near Airoli Village with active aquaculture ponds, wetland vegetation namely Avicennia marina, Excoecaria agallocha, Sonneratia apetala. The data was collected for a period of 18 months from September 2009 to April 2011 during spring tides and neap tides. The vegetation of the study area includes dominant mangrove species Avicennia marina var. accutissima Stapf ex Moldenke and other less dominant species such as Avicennia officinalis Linn., Sonneratia apetala Buch-Ham, Sonneratia alba J. Smith, Bruguiera cylindrica (L.) Blume, Aegeiceras corniculatum (L.) Blanco, Excoecaria agallocha Linn.and associate mangrove species such as Acanthus iillicifolius Linn., Salvadora persica (L.) Garcin, Derris trifoliata Lour., Sesuvium portulacastrum Linn., and patches of mangrove grass namely Aleuropus lagopoides (Linn.) Trin. Ex Thw. The data obtained from the two stations is pooled and displayed in Table 1.
Birds are counted following a wide variety of methods (Bibby 2000). For the present study, point counting was done using binoculars (Olympus 10×50). In this method, a suitable vantage point was selected, and all visible birds were counted. Another method, “total count” was used wherever possible, by walking around the wetlands from the landward side or to specific vantage points to count the birds (Vijayan 1991). A total area of 6 km was investigated for the study.
Bird species observed in the field were identified using standard field guides (Kazmierczak 2000; Grimmet 2013). Photographs were obtained using Canon SX5 whenever and wherever possible. The data was bird species which were grouped under various categories namely, frugivorous, insectivorous, carnivorous, omnivorous depending on their feeding preferences.
In total 95 species of birds were recorded during the study period. All the birds recorded at the selected stations were further categorized according to their feeding behavior to study the preferences of foraging habitats selected by various birds visiting the creek. The bird species were further classified as resident, migratory, and resident migratory bird species (Table 1).
The vegetation of the mangrove ecosystem at Thane Creek supported the population of both waders and terrestrial bird species. A maximum diversity of bird species was reported at Bhandup (Station I) as it provides a mixed habitat that includes Saltpans, grasslands, planted trees, and mangrove vegetation. The strong plant-animal (birds) interaction was observed for White-cheeked Bulbul which were seen in plenty on Salvadora persica during the fruiting season and Baya Weavers were observed in large numbers nesting on Sonneratia apetala.
Species such as Indian Skimmer (Vulnerable and rare), Red-headed Bunting (rare), Eurasian Collared Dove (rare), White Stork (rare) were reported at station I. The near threatened species namely Painted Stork, Lesser Flamingo, Black-headed Ibis (IUCN 2015) were observed during the migratory season from December to March at both the stations.
The distribution of birds as per their feeding behaviour revealed a maximum population of carnivorous (49%), followed by omnivorous (26%), insectivorous (18%), Granivorous (4%), Nectarivorous (2%) and Frugivorous (1%) (Fig. 2). Habitat-wise distribution revealed that 43% of birds were dependent on mudflats and 43% birds on woodland made up of mainly mangroves. This suggested that 86% of birds are dependent on mangroves and mudflats (Fig. 3).
The data revealed that the small patch of approximately 6km of mangrove ecosystem of Thane Creek harbors a fairly large number of bird population and any disturbance of such habitat might affect the avifaunal communities to a large extent. The creek is under severe threat today due to increased anthropogenic usage of wetlands, water pollution, drainage of wetlands, an agricultural conversion that leads to disturbance to nesting sites and habitat destruction.
The vegetation structure of a mangrove ecosystem and mudflats of Thane Creek are used by waders as shelter belt, foraging, roosting and other purposes during spring migration. Most of the birds have specific habitat requirements from season to season, a loss of which may lead to their local extinction. Past and present researchers stated that, Thane Creek is heavily polluted with wastes from both industrial and domestic sources discharged into the creek through several outlets. Regardless of which, it still supports thousands of birds of 95 species, including the small waders and the flamingos. Flamingoes serve to be the major attraction of the creek that has led the forest department to declare certain parts of the creek as Flamingo Sanctuary. The present study area includes this part of the sanctuary and needs especial attention for improving and conserving the condition of the creek. Building of watchtowers, generating awareness about birds and their role in maintaining the balance of the ecosystem needs to be highlighted among the local masses which might be helpful to save the creek from severe anthropogenic stress.
Arunkumar, J.P. Sati & P.C. Tak (2003). Check list of Indian Waterbirds; Envis News letter: Avian Ecology & Inland wetlands. Buceros 8(1): 1–29.
Ali, S. & S.D. Ripley (1987). Compact Handbook of the Birds of India and Pakistan Together with those of Bangladesh, Nepal, Bhutan and Sri Lanka. Oxford University Press, Delhi, 890pp.
Ali, S. (1996). The Book of Indian Birds. Oxford university press, New Delhi, 466pp.
Bibby C.J., N.D. Burgess & D.A. Hill (1992). Bird Census Techniques. Academic Press, London, 67–84 pp.
Bilgrami K.S. (1995). Concept and Conservation of Biodiversity. CBS Publishers and Distributors, Delhi.
Chauhan, R.R., H.U. Shingadia & V. Sakthivel (2008). Survey of avifauna of Borivali mangroves along the coast of Mumbai. Nature Environmental and Pollution Technology 7(2): 229–233.
Chamberlain, D.E., M.P. Toms, M.R. Cleary & A.N. Banks (2007). House Sparrow (Passer domesticus) habitat use in urbanized landscapes. Journal of Ornithology 148: 453–462.
Daniels, R.J.R. (1997). A Field Guide to the Birds of South-Western India. New Delhi: Oxford University Press, 217pp.
Furness, R.W. & J. Greenwood (1993). Birds as Monitors of Environmental Change. Chapman and Hall, London, 356pp.
Grimmett, R., C. Inskipp & T. Inskipp, (2013). Birds of the Indian Subcontinent. Oxford University Press, New Delhi, 528pp.
Islam, M.Z., & A.R. Rahmani, (2004). Important Bird Areas in India: priority sites for conservation. Indian Bird Conservation Network, Bombay Natural History Society and Birdlife International (UK), 1–1200pp.
IUCN (2015). BirdLife International. Ciconia ciconia. 2015, IUCN Red List of Threatened Species. Downloaded on 06 May 2016.
Kazmierczak, K. (2000). A Field Guide to the Birds of the Indian Subcontinent. A & C Black Publishers Ltd., Pica press, 352pp.
Kumar, A. (2003). Acoustic communication in birds. Resonance 8(6): 44–55.
Kumar, A., J.P. Sati, P.C. Tak & J.R.B. Alfred (2005). Handbook on Indian Wetland Birds and their Conservation. Zoological Survey of India, 218pp.
Li, L., D. Hu, D. Duan, E.Gong & L. Hou (2009). Alethoalaornithidae: a new family of enantiornithine bird from the Lower Cretaceous of Western Liaoning. Acta Palaeontologica Sinica 46(3): 365–372
Manakadan, R. & A. Pittie (2001). Standardised common and scientific names of the birds of the Indian subcontinent. Buceros 6(1): 1–37.
Nagelkerken, I., S.J.M. Blaber, S. Bouillon, P. Green, M. Haywood, L.G. Kirton, J.O. Meynecke, J. Pawlik, H.M. Penrose, A. Sasekumar & P.J. Somer-field (2008). The habitat function of mangroves for terrestrial and marine fauna: A review. Aquatic Botany 89: 155–185;
Newton, I., (1995). The contribution of some recent research on Birds to ecological understanding. Journal of Animal Ecology 64: 675–696.
Nitsure, S.R. & M. Pejaver (2002). Species diversity of avifauna at Thane Creek near Rutuchakra Nature Park. Proceeding of National Seminar on Creeks, Estuaries and Mangroves-Pollution and Conservation, 276–282pp.
Oswin, S.D. (2002). Biodiversity and ecology of the Gulf of kutch Mangroves, Gujarat. Proceeding of National Seminar on Creeks, Estuaries and Mangroves-Pollution and Conservation, 78–83pp.
Pawar, P.R. (2011). Species diversity of birds in mangroves of Uran (Raigad), Navi Mumbai, Maharashtra, West coast of India. Indian Journal of Experimental Sciences 2(10): 73–77.
Vijayan, V.S. (1991). Keoladeo National Park Ecology Study: Summary Report 1980–1990. Bombay Natural History Society, Mumbai, 57pp.