This is my fourth sighting of Gull-billed Tern (Gelochelidon nilotica) on La Palma, a species whose status on the Canary Islands is open to discussion. The present bird was discovered on July 22 flying over irrigation ponds in Las Martelas (Los Llanos de Aridane), and my three previous records are all from the same area.
The Gull-billed Tern (Gelochelidon nilotica) is not classified as a rarity for the Canaries by the Spanish Rarities Committee, but it is included in the list of 21 Western Palearctic breeding bird species considered by Eduardo García-del-Rey as irregular winter visitors, rare passage migrants, or even true vagrants (see appendix in "Rare Birds of the Canary Islands", Lynx Edicions, 2013).
Below, are the links to my previous records:
In the photograph above, the bird's interesting feeding technique can be appreciated. It plucks insects, like dragonflies, from the pond while pattering its feet across the surface at high speed. The legs and feet seem to act as distance-gauges, controlling the low skimming.
This fast-flying individual was difficult to track and photograph in an area like Las Martelas. With a couple of wing-flicks the bird was out of sight, foraging over neighbouring ponds, or scouting further afield. Luckily its erratic movements included a few minutes feeding over one of the larger ponds, where I managed to get the images shown here.