John Loines, of the British Antarctic Survey, holds up his arm to fend off an attack by a south polar skua as he checks the nest of one of the birds on Lagoon Island, Antarctica January 14, 2009. The birds, the most southerly in the world, are becoming a threat to planes at Antarctic airstrips by developing a liking for sitting on the runways, which are warmer than surrounding snow. REUTERS/Alister Doyle (ANTARCTICA)