A checklist of the avifauna of Samanatham tank, Madurai, Tamil Nadu, India

: This avifaunal checklist from the Samanatham tank of Madurai District of Tamil Nadu is the first baseline data for this wetland. The study was done from August 2015 to March 2019 and from August 2020 to January 2022. A total of 150 species of birds comprising 17 orders and 52 families were documented. Order wise, Passeriformes 35% (n = 53), Pelecaniformes 15% (n = 22), and Charadriiformes 14% (n = 21) dominated the wetland bird community. The relative diversity (RDi) of families with the most species were Anatidae, Scolopacidae, and Accipitridae with 7.33%. Among the 150 species, 37 (25%) were winter visitors; and one passage migrant Rosy Starling Pastor roseus . The relative abundance indicated that 56% (84 species) were common, 28.6 % (43 species) were uncommon, and 15.4 % (23 species) were rare. The study recorded eight globally Red Listed ‘Near Threatened’ species—Oriental Darter Anhinga melanogaster , Painted Stork Mycteria leucocephala , Black-headed Ibis Threskiornis melanocephalus, Spot-billed Pelican Pelecanus philippensis, Black-tailed Godwit Limosa limosa , Bar-tailed Godwit Limosa lapponica, River Tern Sterna aurantia , & Osprey Pandion haliaetu —and two ‘Vulnerable’ species—Indian Spotted Eagle Clanga hastata & Great Spotted Eagle Clanga clanga .


INTRODUCTION
Bird diversity is high among vertebrates due to their wide distribution.They are biodiversity indicators (Canterbury et al. 2000;Piersma & Lindström 2004) and documentation of their diversity, distribution, and taxonomy in India has been widely done (Ali & Ripley 1987;Kazmierczak 2006;Grimmett et al. 2011;Deomurari et al. 2023).India's share is 12.5% of the global avifaunal richness (Grimmett et al. 2011;Praveen & Jayapal 2023).As there are continuous landscape changes due to economic development in new areas (Jha et al. 2000;Purvis & Hector 2000), regional-level monitoring of birds is essential (Gadgil 1996).Avifaunal studies help to understand the long-term changes in the landscape and the vegetative structures (Rika & Santosa 2007;Rashiba et al. 2022) which aids in conservation planning (Paul & Cooper 2005).Baseline data from any site is essential for any long-term conservation efforts (Peterson et al. 2000;Llanos et al. 2011).
Avifaunal wetland studies in Tamil Nadu had been done in many wetlands like Pallikaranai (Raj et al. 2010), Karaivetti (Gokula 2010), Vaduvoor (Gokula & Raj 2011), and Karangad (Byju et al. 2023).In Madurai the avifaunal studies are scanty and literature search revealed few older studies (Nichols 1944a(Nichols ,b, 1945)).Recent studies done on diversity and distribution were restricted to urban landscapes (Sathasivam 2015;Rajagopal et al. 2022) or thorn forest landscapes (Roopha et al. 2022).Wetlands worldwide are on the decline and India is no exception due to human interventions (Pringent et al. 2012;Sievers et al. 2018).The wetland diversity of Madurai is less documented, except for a few scanty works mentioned from the urban areas, no detailed longterm studies have been made on the diversity of birds in the wetland areas of Madurai.In this background, the current study highlights the status, composition, feeding guilds, and diversity of birds of Samanatham tank, one of the important wetlands of Madurai, Tamil Nadu.

Study Area
Samanatham tank 9.866674°N, 78.14719°E is located in Thiruparankundram block in the Madurai District of Tamil Nadu, India.The tank and its surrounding areas have various types of vegetation, including shrubs, trees, and aquatic plants.The main habitat types observed in the tank include: 1. Open water habitat (WL = Wetland), 2. Agricultural land (AL), 3. Trees (Tr) bordering the wetland, 4. Grassland (GL) on the wetland area, and 5. Scrub habitat (OS = Open scrub type).Some of the common trees found in the area include Neem Azadirachta indica, Mango Mangifera indica, Banyan Ficus benghalensis, Acacia nilotica, and Tamarind Tamarindus indica.The tank and its surrounding areas also have invasive species like Prosopis juliflora.The surrounding area also supports a variety of flowering plants, including Jasmine, Hibiscus, Lotus, and many others.In addition, the tank is home to a variety of aquatic plants, such as water lilies, Water Hyacinth, and Cattails.The area supports a variety of animals including reptiles like snakes & turtles, amphibians like frogs & toads, and fishes like catfish, tilapia, & carp.Overall, the flora and fauna in and around Samanatham tank are an important aspect of the ecosystem of the region and contribute to its rich biodiversity.
Madurai, located in the southern part of India, has a tropical climate with hot and humid summers and mild winters.The temperature ranges from 20 0 C to around 38 0 C. The average annual rainfall is 800 mm.The highest amounts of rainfall are during October and November.

Bird survey method
In the Samanatham tank, bird monitoring was continued for seven years (2015)(2016)(2017)(2018)(2019)(2020)(2021)(2022) to maintain the baseline data.The period of observation was carried out every month from August 2015 to March 2019 and from August 2020 to January 2022.The birds were observed during the peak hours of their activity from 0600-1000 h and 1600-1800 h.Later, bird surveys were conducted using block count and direct visual count methods (Howes & Bakewell 1989;Bibby et al. 2000).In this method, six scanning points were identified (Figure 1) and birds in the blocks were observed using field binoculars (10 x 52 Olympus; Celestron outland 10 x 42) and recorded with a camera (Nikon D750, Canon 100-400 mm f/5.6 lens).We began counting five minutes after the arrival at each scanning points for the waterbirds to acclimate to the human presence.The identification of birds was done using the following field guides (Ali 2002;Grimmett et al. 2011).The common name, scientific name, IUCN Red List status, and migratory status are followed using (Praveen & Jayapal 2023).The feeding guild data for each species were collected from the existing literature (Ali & Ripley 1987;Byju et al. 2023).The data recorded were later analyzed for relative abundance based on the frequency of sightings, as per MacKinnon & Phillips (1993): common (C) sighted from seven to nine times; un-common (UC) sighted from three to six times; rare (R) sighted once or twice.The relative diversity (RDi) of RDi = -----------------------------Total number of species

RESULTS AND DISCUSSION
A total of 150 species of birds belonging to 52 families under 17 orders were recorded from the Samanatham tank (Table 1; Images 1-18).The order Passeriformes dominated the study area with a maximum number of species, i.e., 53 species (35%), and with the lowest Strigiformes, Bucerotiformes, Falconiformes, Psittaciformes, sharing one species (0.66%) each (Figure 2).Similarly, family-wise Scolopacidae, Anatidae, and Accipitridae with relative abundance (RDi) of 7.33 % (11 species each), followed by Ardeidae (nine species) comprised the maximum number of birds species (Table 2).
As per the IUCN Red List (IUCN 2021), the wetland An analysis of the feeding guilds of these birds revealed that 38% (57 species) were insectivorous, 33% (49 species) were carnivorous, 14% (21 species) were omnivorous, 7% (11 species) were granivorous, 5% (eight species each) were frugivorous, and 3% (four species) were nectarivorous (Figure 3).Further analysis of relative abundance based on the frequency of observation indicated that 56 % (84 species) were C (common), 28.6 % (43 species) were UC (uncommon), and 15.4 % (23 species) were Ra (rare).The analysis of data on residential status revealed that out of 150 species, 37 (25%) were winter visitors (WV) and one     The wetland being used by the long-distance migrant shorebirds including the Bar-tailed Godwit and the Black-tailed Godwit, the two Near Threatened species in reasonable numbers makes this an important wintering area for those species.Similar works were reported recently from the Changaram wetlands of Kerala highlighting the need of conserving hitherto undocumented new areas of shorebird wintering sites (Anand et al. 2023).The consistent occurrence of the Near Threatened River Tern represents another ecologically significant species within this geographic region.It is also interesting to note that another two Near Threatened species namely Spot-billed Pelican and Oriental Darter were breeding in the Samanatham tank.Tamil Nadu is home to 535 bird species (Praveen et al. supports, eight globally 'Near Threatened' (NT) species -Oriental Darter Anhinga melanogaster, Painted Stork Mycteria leucocephala, Black-headed Ibis Threskiornis melanocephalus, Spot-billed Pelican Pelecanus philippensis, Black-tailed Godwit Limosa limosa, Bartailed Godwit Limosa lapponica, River Tern Sterna aurantia, & Osprey Pandion haliaetus; two 'Vulnerable' (Vu) species -Indian Spotted Eagle Clanga hastata & Great Spotted Eagle Clanga clanga; and the remaining 140 species are under 'Least Concern' (LC).