Avifaunal diversity of Manjeera Wildlife Sanctuary , Andhra Pradesh , India

1,2,3,4 Wildlife Biology Section, Department of Zoology, University College of Science, Osmania University, Hyderabad, Andhra Pradesh 500007, India 3,4 Systematics, Ecology & Conservation Laboratory, Zoo Outreach Organization (ZOO), 96 Kumudham Nagar, Vilankurichi Road, Coimbatore, Tamil Nadu 641035, India, 1 kpmanjeera@gmail.com, 2 raam27@gmail.com, 3 hyd2masawa@gmail.com (corresponding author), 4 bharisrini@gmail.com

Birds are ideal bio-indicators and useful models for studying a variety of environmental problems as they are very sensitive to the slightest of environmental changes and are important health indicators of the ecological conditions and productivity of an ecosystem (Newton 1995;Desai & Shanbhag 2007;Li & Mundkur 2007).India has a rich avian diversity as it provides for a wide variety of wetland habitats that act as ideal wintering grounds for migratory water birds.The state of Andhra Pradesh is home to as many as 16 sites identified as Important Bird Areas of avifaunal significance (Islam & Rahmani 2005).Manjeera Wildlife Sanctuary is one such Important Bird Area in Andhra Pradesh.Manjeera Wildlife Sanctuary is located 50km northwest of Hyderabad, in Medak District, Andhra Pradesh.It is recognized as an important wetland for migratory birds.The water body provides considerable ecological diversity to support a large population of wetland birds (Islam & Rahmani 2005).One of the important tributaries of the Godavari River system is the river Manjeera.The Manjeera River originates in the Balaghat Hills in Madhya Pradesh, flows thorough Latur District in Maharashtra and Bidar District of Karnataka entering into Medak District of Andhra Pradesh before emptying into the Godavari River at Basara near Nizamabad District (Prasad et al. 2012).The Manjeera basin encompasses an area of 30,914km 2 of Abstract: A total of 164 bird species belonging to 53 families were recorded in the Manjeera Wildlife Sanctuary.Of these 107 species were resident, 55 species were winter migrants and 2 species were summer migrants.The population of the each species in different habitats was estimated.Species richness was observed to be more in agriculture habitat followed by scrubland, grassland and marshy areas, whereas species diversity was observed to be more in scrubland habitat followed by agriculture lands, grasslands and marshy areas.Similarity Index analysis showed that the habitats of agriculture landscrubland are more similar whereas, habitats of scrubland-marshy area show dissimilarity in the sanctuary.which agriculture lands occupy almost 59.4%, followed by pasture lands (39.5%), forest (0.65%) and water (0.45%) (Stalnacke et al. 2012).It is the main source of drinking water to Medak, Nizamabad districts and also to the twin cities of Hyderabad.This is the abode for a number of resident and migratory birds in addition to being home for the Marsh Crocodile Crocodylus palustris.
Density and abundance are the essential ecological information required for population ecology (Buckland et al. 1993(Buckland et al. , 2001)).In the present study, we studied the population density, diversity and distribution of avian fauna in different habitats of the Manjeera Wildlife Sanctuary, Andhra Pradesh, India.

Material and Methods
Study Area: The Manjeera Wildlife Sanctuary located at 17 0 57'52"N & 78 0 02'22"E (Fig. 1) in Medak District, Andhra Pradesh.An area of 2,800 ha between Singoor and Manjeera Barrage was declared as a sanctuary.The sanctuary follows the course of river Manjeera over a length of 36km.The Manjeera Wildlife Sanctuary has nine islands with extensive marshy fringes, which provide good nesting sites for waterbirds.The reservoir supports submergent and emergent vegetation.A narrow margin of Typa sp., Ipomoea sp. and Acacia sp.fringe the waterline, while agriculture lands surround the reservoir and the river.The forest tracts are a typical tropical scrub forest type (Champion & Seth 1968) with Acacia sp., Prosopis juliflora, Pithecelobium dulce, Tamarindus indicus, Butea monosperma and Azadirachta indica as the major species.Other plant species found here are Chrozophora rottleri, Nymphoides hydrophylla, Polygonum glabrum, Leucas aspera, Centella asiatica, Abutilon indicum, Ipomea cornea, Ipomea cairica, Argemone mexicana, Xanthium strumarium, Spilanthus calva, Pistia stratiotes, Eichhornia crassipes, Hydrilla verticillata, Vallisneria spiralis and Marsilea quadrifolia.Grass species like Bothriochloa pertusa, Chloris barbata, Cynodon dactylon, Cyperus rotundus, Heteropogon contortus, and Dactyloctenium aegyptium are present in the sanctuary and its surroundings.This wetland, apart from being the abode for the mugger crocodile, is home to five species of cultured fishes; 60 species of butterflies, 10 species of amphibians; 26 species of reptiles, 18 species of mammals (Prasad et al. 2012).The Manjeera Wildlife Sanctuary experiences a tropical climate with temperatures ranging between 42 0 C in the summers to 15 0 C in the winters and receives about 1000-1100 mm of rainfall annually.The soil type here is red loamy, sandy and black cotton soil, fertile for growing cotton, rice, jowar, maize and sugarcane.
Data Collection: Surveys were conducted between December 2010 and October 2012.The line transect method (Burnham et al. 1980) was used for conducting surveys to estimate abundance of different species of birds, their diversity and to calculate richness indices.The number of transects was based on the relative extents of the habitats.Separate transects were established in each habitat and data was collected and analyzed.Observations were carried out both in the mornings and evenings when the birds were the most active between 06:00-10:00 hr and 16:00-18:00 hr.Four habitat types were chosen namely marshy areas, grassland, agriculture lands and scrubland.Surveys were conducted along 2km long transects with an average nine transects per habitat (6 -12 transects per habitat).Birds were detected and count was kept using binoculars.Photographic record of the birds detected was maintained using a 14.5 mega pixels digital camera (Canon Power Shot 35X).Species identification was done using standard literature (Grimmett et al. 2002) and the listing follows Manakadan & Pittie (2001).
We assigned the abundance of the species observed during the study based on the frequency and number of individuals sighted.The data is presented as ACOR ratings, with abundant being those species which were sighted in many numbers during all transect surveys, common being those species which were sighted in good numbers during all transect surveys, occasional being those species which were sighted in low numbers during some transect surveys and rare being those species which were sighted in very low numbers throughout the study period.Alpha and beta diversities are key concepts for understanding the functioning of ecosystems, for the conservation of biodiversity and for ecosystem management (Magurran 2004).We measured the alpha and beta diversities of the habitats of the sanctuary using the below given formulae D = [ni(ni-1)/N(N-1)] ni = the total number of organisms of a particular species N = the total number of organisms of all species Cs = 2C/ (2C + S1 + S2) where, S1 = the total number of species recorded in the first community S2= the total number of species recorded in the second community c = the number of species common to both communities All statistical analysis was carried out using ecological analysis package Biodiversity-Pro (Biodiversity professional beta version 2.0.0.0), (McAleece et al. 1997).

Results and Discussion
During the present study a total of 164 species of birds belonging to 53 families were recorded, of which 107 species were resident, 55 species were winter migrants and two species were summer migrants (Table 1; Images 1-84).A total of three Vulnerable species (Lesser Adjutant Leptoptilos javanicus, Greater Spotted Eagle Aquila clanga and Indian Skimmer Rynchops albicollis) and three Near Threatened species (Painted Stork Mycteria leucocephala, Oriental White Ibis Threskiornis melanocephalus and Darter Anhinga melanogaster) were recorded.The relative abundance of species in the four different habitats indicated that the birds showed high preference for marsh land habitat followed by agriculture lands in comparison to scrubland and grassland habitats (Table 2).The Simpson's Diversity and Shannon's Diversity Indices show that diversity of birds was high in scrubland followed by agricultural lands, grasslands and marshy area (Table 3), while evenness and equitability indices were high in grassland and scrub land habitats (Table 3).The comparison of species richness of the birds and the number of individuals in the different habitats in the sanctuary indicates that the species richness is high in agriculture lands then followed by scrubland, grassland and marshy area while the number of individuals of birds is high in marshy areas then agriculture lands, scrubland and grassland.The Sorensen's similarity index indicates that habitats of agriculture lands-scrubland, grasslandagriculture lands and grassland-scrubland are more similar (Fig. 2) where as, habitats of scrubland-marshy  areas show dissimilarity (Table 4).The correlation of bird diversity was high in agriculture lands-scrubland, agriculture lands-grasslands and marshy area-agriculture lands, while was low in scrubland-grassland and marshy area-grassland (Table 5).The relationship between the marshy area and scrubland showed inverse correlation indicating that the marshy area habitats have higher bird diversity compared to scrubland habitat.Manjeera Wildlife Sanctuary is known for its rich avian diversity and has been accorded Important Bird Area (IBA) status (Kumar 1994a;Kumar & Choudhury 1994, 1999;Islam & Rahmani 2005).Published records list around 73 species of birds from this site (Kumar 1994a;Kumar & Choudhury 1994, 1999), including many species of Biome-11, the Indo-Malayan Tropical Dry Zone.We recorded 164 bird species belonging to 53 families in the sanctuary and its immediate surroundings.The family Anatidae had the highest value of species richness (14 species) and was followed by the families Scolopacidae (10 species) and Ardeidae (nine species).Anatidae and Scolopacidae have most of all winter migratory birds except the resident birds like Lesser Whistling-Duck Dendrocygna javanica, Cotton Teal Nettapus coromandelianus, Spot-billed Duck Anas poecilorhyncha, and Common Teal Anas crecca.Family Ardeidae has all resident birds, with an exception of Purple Heron Ardea purpurea which is a winter migrant.Members of the family Scolopacidae are all winter migrants.Asian Openbill-Stork Anastomus oscitans (Ciconiidae) and Glossy Ibis Plegadis falcinellus (Threskiornithidae) are only the summer migratory birds.Kumar & Choudhury (1994, 1999) and Kumar (1994b) reported 14 species of birds breeding in the Manjeera Wildlife Sanctuary.Darter Anhinga melanogaster, Asian Openbill Anastomus oscitans, Painted Stork Mycteria leucocephala, Coot Fulica atra and Black-crowned Night Heron Nycticorax nycticorax being the most significant breeders (Kumar 1994b;Kumar & Choudhury 1999).We observed all resident birds to be breeding at Manjeera Wildlife Sanctuary (Table 1).
The Manjeera Wildlife Sanctuary is a bird haven (Choudhury & Pittie 1983;Taher 1998;Moorty 1999).As the Manjeera Reservoir is the main source of drinking water to Greater Hyderabad, water is always stored and properly managed ensuring that water is present throughout the dry season too.The backwaters of the reservoir, as well as the main area, have several islands with extensive marshy fringes, which provide good nesting sites for water birds.The availability of fishes in the river for water birds and availability of grains and insects in the agriculture lands and grass lands, fleshy fruits in the scrubland and secure shelter for nesting are attractive to birds in the sanctuary.Agriculture affects natural ecosystems in more diverse ways, including modifications of landscape, soils, and water supply through deforestation, erosion, channeling, flooding, draining, etc., as well as the elimination or propagation of selected species of plants and animals (Steadman 1996).Compared to the last two decades, increasing of agriculture lands by the irrigation facility from Manjeera River in the area surrounding the sanctuary attracts more bird diversity.
Species like the Bar-headed Goose, Ruddy Shelduck and Demoiselle Crane that visit the Manjeera Wildlife Sanctuary represent 1-3 % of their bio-geographic population threshold determined by Wetlands International (Finlayson et al. 2002) thus leading to its recognition as an Important Bird Area (Islam & Rahmani 2005).Past records denote that the Manjeera wildlife sanctuary is very suitable for winter migratory birds.According to Kumar (1994a), a Greater Flamingo Phoenicopterus ruber, ringed in 1971-74 in Lake Rezaiyeh, Azerbaijan, Iran was recovered at Manjeera Wildlife Sanctuary in the winter of 1986-87.In January 1987, about 3,000 Demoiselle cranes were seen in Manjeera (Kumar 1994c) which according to recent population estimates by Finlayson et al. (2002), would be 3% of the total population of this species wintering in the Indian subcontinent.
Large congregations of Common Teal Anas crecca, Cotton Pygmy-goose Nettapus coromandelianus and Ruddy Shelduck Tadorna ferruginea were also reported from Manjeera (Kumar & Choudhury 1999).During the present study period, no such large congregation was observed.The Lesser Adjutant Leptoptilos javanicus and Indian Skimmer Rynchops albicollis, both vulnerable species, that have been sighted at Manjeera Wildlife Sanctuary in the past have not been reported or sighted during recent times.
Habitat loss is the major factor affecting the population of migratory and resident birds directly or indirectly.The populations of farmland birds like buntings, larks, weavers etc. are very low, compare to waterbirds population because of loss of habitat and excessive use of pesticides in agriculture lands as compared to the last two decade in the sanctuary surroundings (C.Srinivasulu unpub.data).Pesticides can affect farmland birds in a number of different ways and use of pesticides within different farming systems have led to a decline in farmland bird populations (Burn 2000).Waterbirds which were nesting on the Prosopis juliflora plants in the sanctuary decreased because of the habitat loss, due to the collection of firewood by the villagers.Hence, habitat reserves are an essential element in an ecosystem to conserve biological diversity.
These four types of habitats of the Manjeera Wildlife Sanctuary support large numbers of migratory and resident species of birds.Availability of food in different seasons, different types of vegetation, agricultural lands, accessibility of water in the area, field activities and good weather conditions were observed for favorable conditions for birds to survive in this area.Birds are a good medium for dispersing seeds, pollinating plants, biological control and they are important to continue the ecological cycle.Long term assessment of bird species richness will help in understanding the impact of changing environment on birds and also support in creating a scientific database for proper management of the ecosystem to ensure better conservation, both of the habitats and the avian diversity.

Figure 2 .
Figure 2. Similarity between habitats with respect to species richness at Manjeera Wildlife Sanctuary, Medak District, Andhra Pradesh, India