White-winged Tern: Hunting technique

An earlier post gives the non-breeding, breeding (above) and transitional plumages of the White-winged Tern (Chlidonias leucopterus), also known as White-winged Black Tern documented by Dr Jonathan Cheah Weng Kwong at Kranji.

This is a migratory bird that moves down the Malay Peninsula to Singapore and beyond to as far as Australia to winter.

This tern is a generalist feeder, taking aquatic as well as terrestrial insects, small fish and tadpoles. It has a number of feeding techniques: aerial feeding, hawking flying insects, hover-dipping and contact-dipping. However, it does not plunge-dive.

The images provided (above, below) show the bird indulging in contact-dipping. Flying slowly and just above the water, it looks for a fish swimming just below the water surface. Once spotted, the bird turns it head downwards and sideways and plunges its bill into the water to snatch the fish. It simply continues with its flight with the fish securely clamped in its bill.

Reference:
Gochfeld, M. & Burger, J. (1996). Family Sternidae (Terns). Pp. 624-667 in: del Hoyo, J., Elliott, A. & Sargatal, J. eds. Handbook of the birds of the world. Vol. 3. Hoatzin to Auks. Barcelona: Lynx Editions.