22 International Journal of Zoology Studies www.zoologyjournals.com ISSN: 2455-7269 Received: 02-02-2022, Accepted: 17-02-2022, Published: 04-03-2022 Volume 7, Issue 1, 2022, Page No. 22-28 Community structure and habitat utilization with reference to water depth by wetland birds at Anasagar Lake, Ajmer, Rajasthan Sonali Khiyani 1 , Rounak Choudhary 2 , Vivek Sharma 1* , Subhash Chandra 1 , Praveen Mathur 2 1 Department of Zoology, Maharshi Dayanand Saraswati University, Ajmer, Rajasthan, India 2 Department of Environmental Science (Centre for Excellence), Maharshi Dayanand Saraswati University, Ajmer, Rajasthan, India Abstract Anasagar lake of Ajmer, Rajasthan is one of the largest human-made lakes in central Rajasthan. The lake has an important place in the migratory route and wintering habitat for migratory birds of Europe, Asia and Africa. The water birds and water-associated birds are directly dependent on wetlands and are affected adversely due to the loss and degradation of wetlands. Various studies indicate that managing water bodies helps in mitigating the adverse effect on migration and habitat utilization of birds. The hypothesis of this research is to examine the diversity of water and wetland-dependent avifauna including the number of individuals present in two classified zones of Anasagar Lake that are Deep water zone and Shallow water zone, avian fauna that uses the two classified zones as feeding ground were accounted for observations. Keywords: water depth, avifauna, Ajmer, Anasagar, niche Introduction Wetlands play an important role in the protection of biodiversity and is an essential habitat for various type of living components in an ecosystem (Dai et al., 2019) [4] . More than 50 percent of wetlands in the world are lost in the past hundred years, and the rest are degrading due to the influence of anthropogenic activities (Fraser and Keddy, 2005) [7] . Migratory birds, the important species of water bodies are majorly affected due to changes in water levels (Bancroft et al., 2002) [2] . Habitat suitability is directly proportional to habitat use and habitat quality (Coppes et al., 2018) [3] . Water bodies provide diversified benefits to water bird species such as a site for roosting, foraging, and nesting (Erwin and Beck, 2007) [6] . Studies indicate that depth of the water body is an important variable that affects the use of wetland habitat by water bird s (Elphick and Oring, 1998) [5] . Water depth directly affects the foraging efficiency of water birds especially in the case of shorebirds because of their morphology including the length and shape of tarsometataris, birds with long necks, bills, and legs can feed efficiently in deeper habitats (Baker, 1979; Powell, 1987) [1, 115] . Water bodies with deeper water levels support a higher density of diving water birds (Stapanian, 2003) [18] but still the birds need a roosting site for such waterfowls (Hattori and Mae, 2001) [11] . The increased depth slows the locomotion of water bird s because of increased resistance to water (Gawlik, 2002) [8] . Previously, in various studies the anasagar lake is known to host more than 95 species in the water zone and nearby terrestrial regions (Jadon et al., 2019) and 58 species associated with water in anasagar (Prakash and Dutt, 2018) [16] and the wetlands of central Rajasthan near anasagar lake are reported to host more than 90 species of birds (Sharma et al., 2012) [17] In this study we explored the preference and utilization of deep and shallow water zones by water bird s at anasagar lake, and discussed the importance of conservation of the lake. Materials and Methods Study area Anasagar lake situated in the district of Ajmer in State Rajasthan of India at 26 o 28’N and 74 o 37’E coordinates is one of the largest artificially constructed lakes spanning an area of about 330 hectares. The depth of anasagar lake is 16ft. The water body stores the rainwater running from catchment areas and treated sewage water. The lake is surrounded by aravalli hills and lies in an ecotone between arid and semiarid Rajasthan. The lake is surrounded by urban settlements from all sides leaving no other natural habitats within the range. Survey Methods The field surveys and observations were recorded for two years from January 2020 to January 2022. Birds were recorded systematically by walking on the pathways along the shorelines and the point count method was implemented from fixed observation points. The identification of birds was done using available literature (Manakadan and Pittie, 2001; Gill and Donsker 2017) [14, 9] . Statistical Analysis was done with the help of PAST (Hammer et al., 2001) [10] Software along with Relative Diversity Index (RDi) (Torre-Cuadros, 2007) [19] , and the