Wetlands Ecology and Management 13: 69–72, 2005. # Springer 2005 Factors influencing flamingo (Phoenicopterus roseuis) distribution in the Pulicat Lagoon ecosystem, India D. Asir Ramesh and S. Ramachandran Integrated Coastal Zone Management Training Program, Institute for Ocean Management, Anna University, Chennai-25, India; *Author for correspondence (e-mail: asiramesh@yahoo.com; phone: 91-44-22200158) Received 7 December 2002; accepted in revised form 10 July 2003 Key words: Bird density, Flamingo, Lagoonal systems, Population distributions, Water depth Abstract The shallow (1.5 m) Pulicat Lagoon in India supports a variety of migratory birds (125 species), especially flamingos and storks. Flamingo populations in this area are dominated by Phoenicopterus roseuis, and they are densely distributed in shallow areas and fringes of the lake where the water level is below 40 cm. Eighteen flamingo groups are distributed around the lagoon with 750 individuals per group. Flamingo populations are greatest in places where fish, algal, and benthic faunal biomass are highest. Physiological adaptations and morphology of flamingo are important criteria for selecting feeding locations. Introduction Birds are an important and major migratory biolo- gical component of coastal wetlands. Coastal lagoons support significant migratory bird popula- tions and provide nesting, breeding, and resting grounds for these birds. Avian population density and diversity depend on available food and shelter resources. India has two major coastal lagoons, Chilka and Pulicat lagoons, and these lagoons attract a variety of migratory bird populations. The most important common migratory birds associated with India’s lagoonal ecosystem are herons, storks, flamingos, and pelicans. Of the over 2094 kinds of birds occurring on the Indian subcontinent, 344 are migrants, coming mostly from the Northern Eurasian region. Pulicat Lagoon covers more than 250 km 2 . Lake size and abundance of invertebrates are the main factors contributing to the distribution of bird populations (Hurlbert 1991). Water depth is also important, because it regulates the bird’s feeding capacity over the benthic fauna (except diving birds) (Erwin et al. 1994). Vegetation distribution is also an important criterion for avian distribution and diversity in coastal wetlands (Mulyani and DuBowy 1993), with areas of seagrass and sea- weeds being potential sites of greatest benthic fau- nal distribution. Bird populations globally are threatened by habitat alteration due to anthropogenic activities and natural changes. In India, natural changes include decreasing water depths due to uplifting processes, and anthrophogenic activities include the conversion of lagoons into industrial land (agri- culture and aquaculture come under the Industries Act). During the No Impact Zone Studies on the Pulicat Lake ecosystem (funded by Department of Ocean Development, Government of India), Phoenicopterus roseuis was found to be distributed sporadically in the more shallow areas of the lake. The objective of the current study was to determine the reason for density and distributional variations of P. roseuis within the lagoon.