Description:-
Size 36-45 cm long. Plumage: most of body sooty brown; white forehead merges into blue- or lavender-grey cap contrasting with dark lores and earcoverts; flight feathers and wedge-shaped tail nearly black. Immature with white on forehead only, no cap; upperparts and wings with white feather edges. Bare parts: iris brown; robust bill black; feet and legs brownish black.
References:-
Adriaens, P. (2014). Anous stolidus (Linnaeus, 1758). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=212629 on 2015-02-12
BirdLife International (2015) Species factsheet: Anous stolidus. Downloaded from http://www.birdlife.org on 12/02/2015.
Praveen, J. 2013. Ocaeanic birds of south India. An update. Sea Swallow 62: 87-91.
Sashikumar,C., Praveen, J. Palot, M.J., Nameer, P.O. 2011. Birds of Kerala: status and distribution. DC Books, Kottayam. Pp. 590–593