MIGRATORY WETLAND BIRDS DIVERSITY IN LOWER CHOTA NAGPUR PLATEAU WITH SPECIAL REFERENCE TO PURULIA DISTRICT, WEST BENGAL, INDIA

Soham Chowdhury UG Student, Dept. Of Zoology, Bankura Sammilani College, Bankura, West Bengal, India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 15 August 2020 Final Accepted: 18 September 2020 Published: October 2020


ISSN: 2320-5407
Int. J. Adv. Res. 8(10), 357-367 358 bird species play a significant role in the aquatic ecosystem and increase faunal diversity. However now-a-days, migratory birds' diversity has been decreasing due to the destruction of natural habitats and anthropogenic interference [Sanderson, E.W. Et al;(2002)]. Avian species of wetlands are facing tremendous pressure due to the unethical behaviour of human beings.
In the Indian subcontinent the majority of migratory birds are winter migrant. It is estimated that over hundred species of migratory birds fly to India, either in search of feeding grounds or to protect themselves from severe winter bite of their native habitat (According to ENVIS Centre of Avian Ecology) .
In West Bengal, District Purulia is an adobe of various migratory as well as residential birds. A trend has been observed that migration of avian species is decreasing year after year (Anandabazar Patrika; 9 th January, 2017). Considering this scenario, an effort has been made to study the avifaunal migratory species of the wetlands of this district. Among the major wetlands of Purulia basically eight of them(Baranti Reservoir, Muradi ; Adra Saheb Bandh lake; Purulia Saheb Bandh; Futiyari Dam; Murguma Dam; Jorisha Dam; Kalidaha Jore, Indrabil and Kumari Dam) attract a large number of migratory birds in winter. There are only a few reports available till date about avian species diversity of the entire lower Chotanagpur Plateau region.

Objectives of the Study:-
An effort has been taken to focus on the following objectives through the present study. 1. To focus the geographical position of the study area. 2. To analyse migratory species diversity. 3. To analyse the richness of migratory birds.

Observation Period:
The present study has been conducted for four consecutive years (November 2017 to March 2020) to record avian migratory birds' diversity.

Study area:
Purulia District belongs to Chotanagpur Plateau of western part of West Bengal. Purulia has a sub tropical climate nature and bears low hill, highlands, arid landscape and high vegetation. Due to undulated topography nearly 50% of the rainfall flows away as runoff. The district is covered by mostly residual soil formed by weathering of bed rocks.  The present study has been conducted in eight important wetlands spread over Purulia district of West Bengal ( Fig.  1 and Fig.2). The observed region is divided into three areas (urban, semi urban and rural). Purulia Saheb Bandh is situated in urban area; Adra Saheb Bandh is located in semi-urban area and rest six are located in rural belt.

Adra Saheb Bandh:
It was constructed by British administration of Bengal Nagpur Railway in the period 1901-1902. Now the owner of the lake is South Eastern Railway. Located at 86 0 70'E longitude and 23 0 48'N latitude and it is 3km northeast of Adra Railway Station. Total area of the lake is 6.31sq.km. Lake water is used mainly for supplying potable water to Adra Township.

Baranti Reservoir:
It is situated between Muraddi Hill and Baranti Hill near Ramchandrapur, 3KM from Muraddi Rail Station in Saturi Block of Purulia. Its location is 23.5778 0 N 86.8450 0 E. It had been constructed for irrigation project in 1975.It is commonly known as Muraddi Lake. Total area of the lake is 6sq.km, surrounded by forest area. It has rich biodiversity with large number of flora and fauna.

Futiyari Dam:
Is situated 23km from Purulia town. Coordinates: 23.3833 0 N 86.5577 0 E. Total Volume of the Dam is 533TCM. It was operated in 1980s and maintained by I&W Dept., Govt of West Bengal to develop agriculture.

Jorisha Dam:
It is also known as Beko Dam. The dam is situated at Jorisha, 4km from Adra rail town with coordinates: 23°28'46"N 86°37'16"E. It was operated in the year 1990 and maintained by I&W Dept., Govt of West Bengal. Total area of the reservoir is 1.2sq.km.

Kalidaha Jore:
Kalidaha Jore is located at 23 0 37'N 86075'E in Kalidaha near Indrabil in Kashipur Block. To interconnect nearby villages through waterway Govt. constructed this wetland in 1964-65. It is occupies about 9 acres of land. Water of the perennial wetland is used for domestic, irrigation, fishing etc.

Kumari Dam:
The dam is situated on Kumari River at Dubrajpur, 26km from Puruliya with coordinates: 23 0 9'54''N 86 0 17'10''E. It was operated in the year1984 and maintained by I&W Dept., Govt of West Bengal. The dam is mainly used for the purpose of irrigation. Total area of the reservoir is 21 acres.

Murguma Dam:
The dam is located in the north of Begunkodar within Jhalda Block at the northern foot of Ayodha Hill and is about 55 kms from Purulia town. The dam is on the tributary of Kangsabati River. Coordinates: 23 0 19'10.03''N, 86 0 3 ' 7.6 '' E. It was operated in 1982 and maintained by I&W Dept., Govt of West Bengal. Total area of the lake is 2sq.km, surrounded by forest area.

Purulia Saheb Bandh:
It is the lung of Purulia town. Size of the wetland is around 70 acres with 23.3395 0 N, 86.3586 0 E. It was constructed by the then British administration during 1838-1843 for supplying drinking water. It is also named as Nibaronsayar in accordance with the name of Nibaran Chandra Dasgupta, a freedom fighter and great patriot of Purulia.

Data Source & Methodology:-
This study is mainly based on primary and secondary data sources. For primary data, avian species have been observed and recorded directly in the field. Different research papers, Wikipedia, different books, internet access have been used as secondary data sources. Regular field trips were made throughout this period. Two different methods have been adopted to study avifaunal diversity. First one is Line Transects Method and second one is Point Count Method. Through these said methods, a checklist is prepared. Nicon Aculon Binocular A211 10-22x50 has been used for close observation of birds and Nicon D7200 camera, with Nikkor Lens 70-300 mm for photography. The check list of species has been prepared following Ali(1996), Grimmett and Inskipp(2011). To get better response in observations relating to peak behavioral activities of birds, suitable time (1 or 2 hours after sunrise or before sunset) has been considered.

Result and Discussion:-
Species diversity is a measurement of an ecosystem's species richness and species evenness. More species richness will contribute to increase in biodiversity also which is an important aspect on biodiversity conservation.
The checklist of observed migratory avian species in Purulia District along with their order, common name, scientific name, families, habit location, visibility, from where they migrate and IUCN status are given in Table 1.
In total, 43 species of birds belonging to 8 orders and 12 families have been observed. Out of total 43 migratory bird species, 83.72% are winter Migrant and 16.28% Local Migrant (Fig 3). Order Passeriformes are dominant in wetlands of Purulia, including 3 families and 7 species. Family Anatidae (34.88%) are dominant with 15 no of species, followed by Scolopacidae (16.28%), Charadriidae (9.30%) and Motacillidae (9.30%). Migratory birds' diversity in terms of different order is given in Fig.4.

Conclusion:-
Present study reveals that the wetlands harbour a large number of migratory birds especially in winter season and play a crucial role to enrich the biodiversity. It is observed that the wetlands are undergoing unwanted change in biodiversity due to anthropogenic pressure which creates terrible effect on migratory birds. Notably, the number of migratory birds in Purulia Saheb Bandh is reducing severely. To come back the earlier well favourable or more favourable environment to the migratory bird species, first of all it is needed to develop awareness among civilized being like human. To aware in depth awareness programme to be run periodically containing the facts like why people should safeguard wetlands, socio-economic value of wetlands in continuous way. Identifying the specific goal of specific wetland, decision against some infrastructure development may be taken for healthy and flourish environment in the wetlands such as building up watch tower. Activities of the tourists are also causing disturbances to the lake ecosystem. There should be strict management rules for visitors for the conservation of biodiversity in the wetlands and the area should be announced as a polythene free zone. Govt. should take further steps to protect wetlands' diversity. A sustainable and holistic management planning is necessary for conservation of wetlands.