Diversity and habitat associations of avifauna in the Poovar Estuary, Kerala, India

Authors

  • B.S. Bipitha Department of Zoology, BJM Government College, Chavara, Kollam, Kerala 691583, India.
  • V. Reshmi Department of Zoology, BJM Government College, Chavara, Kollam, Kerala 691583, India.
  • H. Maitreyi Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, Tamil Nadu 608502, India.
  • H. Byju Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, Tamil Nadu 608502, India.

DOI:

https://doi.org/10.11609/jott.10212.18.7.29226-29237

Keywords:

Avifaunal list, biodiversity, backwater, beach, estuary, habitats, migratory birds, species assemblage, urban birds

Abstract

This study assessed bird diversity in Poovar, a coastal wetland complex in Thiruvananthapuram district, Kerala, India, from August 2024 to July 2025. 88 bird species from 17 orders and 37 families were documented, encompassing both resident and migratory populations. According to the IUCN Red List, all species were categorized as ‘Least Concern’ except for the River Tern Sterna aurantia and Oriental Darter Anhinga melanogaster, listed as ‘Vulnerable’ and ‘Near Threatened’, respectively. Based on migratory status, 56 species were residents and 32 were winter visitors, highlighting the role of Poovar as a significant refuge for migratory waterbirds along the southwest coast of India. Feeding guild analysis showed that 34% of species were insectivorous, followed by carnivores and piscivores, reflecting the functional diversity of the community. Habitat association indicated waterbirds utilized varied habitats, showing overlap in habitat-specific assemblages such as backwater, mangroves, and beaches, emphasizing the influence of habitat heterogeneity on avian distribution. Urban areas showed a distinctive species composition having little overlap with farmland assemblages. The habitat mosaic of Poovar supports a diverse and dynamic avifaunal assemblage. Habitat association analysis indicated that waterbirds utilized a variety of habitats.

References

Anand, J., H. Byju, A. Nefla, S. Abhijith, O.R. Reshi & K.M. Aarif (2023). Conservation significance of Changaram wetlands—a key wintering site for migratory shorebirds and other waterbirds in the western coast of Kerala, India. Journal of Threatened Taxa 15(1): 22410–22418. https://doi.org/10.11609/jott.8089.15.1.22410-22418

Archana, T.R., A. Nefla, H. Byju, S. Almaroofi, O.R. Reshi, A.S. Alatawi & K.M. Aarif (2024). Effects of plant and avian frugivore interaction networks on landscape patterns and seed dispersal functions in the southern Western Ghats, India. Ornithological Science 23(1): 35–43. https://doi.org/10.2326/osj.23.35

Bibby, C.J., N.D. Burgess, D.A. Hill & S.H. Mustoe (2000). Bird Census Techniques. 2nd Edition. Academic Press, London, 302 pp.

Byju, H., N. Raveendran, S. Ravichandran & R. Kishore (2023a). An annotated checklist of the avifauna of Karangadu Mangrove Forest, Ramanathapuram, Tamil Nadu, with notes on the site’s importance for waterbird conservation. Journal of Threatened Taxa 15(3): 22813–22822. https://doi.org/10.11609/jott.8356.15.3.22813-22822

Byju, H., N. Raveendran, S. Ravichandran & R. Kishore (2023b). Importance of conserving a critical wintering ground for shorebirds in the Valinokkam Lagoon—a first study of the avifaunal distribution of the southeastern coast of India. Journal of Threatened Taxa 15(8): 23696–23709. https://doi.org/10.11609/jott.8494.15.8.23696-23709

Byju, H., N. Raveendran & S. Ravichandran (2023c). Distribution of avifauna on twenty-one islands of the Gulf of Mannar Biosphere Reserve, India. Journal of Threatened Taxa 15(2): 22574–22585. https://doi.org/10.11609/jott.8112.15.2.22574-22585

Byju, H., H. Maitreyi, N. Raveendran & R. Vijayan (2024a). Avifaunal diversity assessment and conservation significance of Therthangal Bird Sanctuary, Ramanathapuram, Tamil Nadu: insights about breeding waterbirds. Journal of Threatened Taxa 16(9): 25802–25815. https://doi.org/10.11609/jott.8999.16.9.25802-25815

Byju, H., H. Maitreyi, S. Ravichandran & N. Raveendran (2024b). Avifaunal diversity and conservation significance of coastal ecosystems on Rameswaram Island, Tamil Nadu, India. Journal of Threatened Taxa 16(12): 26198–26212. https://doi.org/10.11609/jott.9248.16.12.26198-26212

Byju, H., K.A. Rubeena, C.T. Shifa, T.R. Athira, K. Jishnu, J. Singh, A. Sohil, S. Kushwah, A. Kumar, J. Anand, K.M. Rajaneesh, S. Manokaran, D.R. Gijjappu, O.R. Reshi, O. Ilyas, N. Sharma, K.K. Junaina, N. Raveendran, T.M.V. Mumthaz & M. Nasser (2024c). Transitioning wintering shorebirds to agroecosystem: a thorough evaluation of habitat selection and conservation concern. Diversity 16: 23. https://doi.org/10.3390/d16010023

Byju, H., H. Maitreyi, R. Vijayan, R. Natarajan & B.A.V. Maran (2025a). The avifauna of Ramanathapuram, Tamil Nadu, along the southeast coast of India: waterbird assessments and conservation implications across key sanctuaries and Ramsar sites. PeerJ 13: e18899. https://doi.org/10.7717/peerj.18899

Byju, H., H. Maitreyi, N. Raveendran, S. Ravichandran & R. Vijayan (2025b). Avifaunal diversity and conservation status of waterbirds in Pillaimadam Lagoon, Palk Bay, India. Journal of Threatened Taxa 17(4): 26789–26802. https://doi.org/10.11609/jott.9432.17.4.26789-26802

Byju, H., H. Maitreyi. S. Ravichandran (2025c). Temporal dynamics of shorebird assemblages in Valinokkam Lagoon, Southeast India: A new wintering site along the Central Asian Flyway. Ornis Hungarica 33(2): 22–42. https://doi.org/10.2478/orhu-2025-0018

Byju, H., H. Maitreyi, K.M. Aarif, K.A. Rubeena & S. Ravichandran (2025d). Temporal patterns in shorebird diversity and abundance at Dhanushkodi Lagoon: a critical wintering ground along India’s southeast coast. Thalassas 41: 151. https://doi.org/10.1007/s41208-025-00908-1

Byju, H., H. Maitreyi, K.M. Aarif, K.A. Rubeena & S. Ravichandran (2025e). Diverging roles of natural and artificial lagoons: Supporting shorebird communities in the Gulf of Mannar, southeast coast of India. Journal of Coastal Conservation 29(6), 1–15. https://doi.org/10.1007/s11852-025-01163-5

Gill, F., D. Donsker & P. Rasmussen (Eds.) (2024). IOC World Bird List v.14.1. https://www.worldbirdnames.org

Greenacre, M. & J. Blasius (2006). Multiple Correspondence Analysis and Related Methods. Chapman & Hall/CRC, 608 pp.

Grimmett, R., C. Inskipp & T. Inskipp (2011). Birds of the Indian Subcontinent. 2nd Edition. Oxford University Press, New Delhi, 528 pp

IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-2. https://www.iucnredlist.org

Kumar, S.N., R. Muraleedharan, R. Kalyani, H. Maitreyi & H. Byju (2025). Avifaunal diversity of Chinnavedampatti Lake: an urban wetland in Coimbatore, Tamil Nadu, India. Journal of Experimental Zoology India 28(2): 1383–1395. https://doi.org/10.51470/jez.2025.28.2.1383

Lorenzón, R.E., A.H. Beltzer, P.F. Olguin & A.L. Ronchi-Virgolini (2016). Habitat heterogeneity drives bird species richness, nestedness and habitat selection by individual species in fluvial wetlands of the Paraná River, Argentina. Austral Ecology 41(7): 829–841. https://doi.org/10.1111/aec.12375

Ma, Z., Y. Cai, B. Li & J. Chen (2010). Managing wetland habitats for waterbirds: an international perspective. Wetlands 30(1): 15–27. https://doi.org/10.1007/s13157-009-0001-6

Mathibalan, T., H. Byju, H. Maitreyi, N. Raveendran, S. Sheela & J. Anand (2026). Diversity and composition of avian populations in Sivagalai Wetland, Thoothukudi, India. Journal of Experimental Zoology India 29: 965–974. https://doi.org/10.51470/jez.2026.29.1.965

Manikannan, R., S. Asokan & A.M.S. Ali (2012). Abundance and factors affecting population characteristics of waders (Charadriiformes) in Great Vedaranyam Swamp of Point Calimere Wildlife Sanctuary, southeast coast of India. International Journal of Ecosystem 2(1): 6–14. https://doi.org/10.5923/j.ije.20120201.02

Narayanan, S.P., A.P. Thomas & B. Sreekumar (2011). Ornithofauna and its conservation in the Kuttanad wetlands, southern portion of Vembanad-Kole Ramsar site, India. Journal of Threatened Taxa 3(2): 1663–1676. https://doi.org/10.11609/JoTT.o1870.1663-76

Panda, B.P., B.A.K. Prusty, B. Panda, A. Pradhan & S.P. Parida (2021). Habitat heterogeneity influences avian feeding guild composition in urban landscapes: evidence from Bhubaneswar, India. Ecological Processes 10(1): 31. https://doi.org/10.1186/s13717-021-00327-6

Praveen, J., R. Jayapal, T. Inskipp, D. Warakagoda, P.M. Thompson & R.C. Anderson (2023). Checklist of the birds of the Indian subcontinent (v7.1). Website: http://www.indianbirds.in/indian-subcontinent/. Accessed on 12.x.2025.

R Core Team (2025). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/. Accessed on 12.x.2025.

Rashiba, A.P., K. Jishnu, H. Byju, C.T. Shifa, J. Anand, K. Vichithra, Y. Xu, A. Nefla, S.B. Muzaffar & K.M. Aarif (2022). The paradox of shorebird diversity and abundance in the west coast and east coast of India: a comparative analysis. Diversity 14: 885. https://doi.org/10.3390/d14100885

Sekercioglu, C.H. (2006). Increasing awareness of avian ecological function. Trends in Ecology & Evolution 21(8): 464–471. https://doi.org/10.1016/j.tree.2006.05.007

Sharma, P., G.S. Sekhon & T.K. Kler (2024). Avian diversity and habitat assessment of insectivorous bird species in arid agro-ecosystem of Haryana, India. Journal of Applied & Natural Science 16(4): 1849. https://doi.org/10.31018/jans.v16i4.XXXX

Shree, N.R. & E. Malathi (2024). A checklist of avifauna from different microhabitats in Muttukadu backwaters, Tamilnadu, India. Journal of Asia-Pacific Biodiversity 17(1): 169–178. https://doi.org/10.1016/j.japb.2023.12.007

Torre-Cuadros, M.D., L.A.L. Herrando-Perez & S.K.R. Young (2007). Diversity and structure patterns for tropical montane and premontane forests of central Peru, with an assessment of the use of higher-taxon surrogacy. Biodiversity and Conservation 16: 2965–2988. https://doi.org/10.1007/s10531-007-9181-2

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Published

26-07-2026

Issue

Vol. 18 No. 7 (2026)

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Articles

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Copyright (c) 2026 B.S. Bipitha, V. Reshmi, H. Maitreyi, H. Byju

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