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Gull-billed Tern (Gelochelidon nilotica)

With a shorter, thicker bill than the rest of the terns, the Gull-billed Tern might be expected to have a rather different diet to that of its relatives. And so it does. It does eat fish – it could hardly be a tern if it didn’t – but it also catches a uniquely wide range of other animal foods, including insects, earthworms, crabs, frogs, reptiles, and occasionally even small birds. Whatever it gets depends on what is available and in one Italian study nearly two-thirds of the diet consisted of lizards! Insects are also regularly very important, but as far as food is concerned, it’s an opportunist.

Whilst every other tern in the world feeds predominantly over water or wet places, the Gull-billed Tern does not necessarily do so. Its main foraging method is to fly low over the water surface, dipping down every so often to snatch whatever it sees, but there is no reason why the very same method cannot be transferred to dry ground. This is what the Gull-billed Tern often does and, as it quarters over grasslands, orchards or agricultural fields with no water evident nearby, it looks completely out of place.

With such varied and plentiful feeding preferences one might expect Gull-billed Terns to be everywhere, but they are not. In fact they are decidedly scarce, with a European population of no more than 4000 pairs. They do require islands, dunes, shores and pastureland on which to nest, and are very susceptible to disturbance, but perhaps the main reason is that Europe lies on the very north of their range, and they prefer warmer climates.

Most Gull-billed Terns in Europe breed in small numbers among colonies of other gulls and terns. Display involves less aerial display than in most other terns, and nests are usually close to vegetation.