Arctic Terns

Context: A huge flock of Arctic Terns has arrived at the Gulf of Mannar Marine biosphere reserve.

Migration of birds occurs every year over the Central Asian Flyway; more birds are being seen this year compared to previous years.
The population of the migratory birds that has got to to the Gulf of Mannar till now is far more than seen in previous years.
The seasonal ritual of migration occurs every year over the Central Asian Flyway (CAF), comprising 29 countries including Iraq, Kuwait, Qatar, Kyrgyzstan, Nepal, India, Bhutan, Myanmar and Maldives.
The CAF is the shortest flyway in the world.
On this route, the migratory birds travelling on the east of CAF also halt at the adjoining sanctuary habitats in Dhanushkodi and other water bodies and inter-tidal shores.
The Arctic birds begin their journey through India from the Bhitarkanika National Park, Odisha, and fly over to Kanniyakumari, the southern-most tip of coastal Tamil Nadu.
When birds return to the same undisturbed habitats in search of food and rest, it indicates a healthy environment.