Synopsis Acknowledgements. Credits for Photographs. 1. Introduction. 2. Historical aspects and review of literature. 3. Taxonomy. 4. Radiography and wing formula of Collocalia Unicolor. 5. Known distribution. 6. Study area. 7. Topography and climate of the study area. 8. Study period. 9. Methodology. 10. Ecology and behaviour. 11. Recent observations and results. 12. Tabulation of recent observations and published records of occurrence and status of Collocalia Unicolor. 13. Other fauna and flora on the Vengurla Rocks Archipelago and Netrani Island. 14. Facts about nest trade from 1990's onwards. 15. Protection measures taken. 16. Recommendations for conservation. 17. References.