Sterna paradisaea no bird on Iceland is so graceful and yet such a nuisance as the arctic tern. The acute wedged tail, the sharp hooked wings, the red legs and beak, and the black head makes this bird exceptionally pretty. At the same time however, they are very aggressive to humans coming near their nests. Anyone who has been to Iceland during summer knows that if you are at a grassland near the coast you will be attacked by these rather small birds. The attack consists of dive-flights to your head. At the very last moment they will back off rarely ever hitting you. It can be very irritating. The worst thing you can do is to react: it will make them even more nervous and they might drop faeces on you. The best thing to do is to take a stick or so and point it straight above your head. It redirects their focus of attack. Their aggressive nature offers protection for many other breeding birds like ducks. They are truly special birds, wintering in southern areas of the southern hemisphere and migrating north to the (sub-)arctic regions of the northern hemisphere to breed. They generally feed on fish. It is therefor said that no creature on earth is exposed to so much daylight. However, the longest recorded migratory flight to my knowledge has not been recorded for the arctic tern but by its cousin the common tern (western Europe to the antarcti regions south of Austrlia/New Zeeland). Their hunting technique is in part hovering more or less like kestrels in the air and then diving down to the water surface. At other times they glide over the water surface in order to find fish.