Hanne & Jens Eriksen / Wilson's storm petrel (Oceanites oceanicus) fluttering over the sea, yellow foot web visible, Oman, November

David Tipling / Wilson's storm petrel (Oceanites oceanicus) in flight over Southern Ocean. South Georgia.

David Tipling / White-faced storm petrel (Pelagodroma marina) two in flight, Hauruki Gulf, New Zealand.

Eric Medard / Storm petrel (Hydrobates pelagicus) in flight at night, taken with infrared picture, Wales, UK, July.

Eric Medard / Storm petrel (Hydrobates pelagicus) in flight at night, taken with infrared picture, Wales, UK, July.

Eric Medard / Storm petrel (Hydrobates pelagicus) in flight at night, taken with infrared picture, Wales, UK, July.

Hanne & Jens Eriksen / Wilson's storm petrel (Oceanites oceanicus) in flight skimming the water, Oman, September

Ole Jorgen Liodden / White-faced storm petrels (Pelagodroma marina maoriana) flying over sea, and walking on the water, Chatham Islands, New Zealand

Tui De Roy / White-vented storm petrel (Oceanites gracilis galapagoensis) 'walking' on surface of water whilst foraging, Galapagos

Tui De Roy / White-vented storm petrels (Oceanites gracilis galapagoensis) 'walking' on surface of water whilst foraging, Galapagos

Frederique Olivier / Wilson's storm petrel (Oceanites oceanicus) on rock, Antarctica, November.

Frederique Olivier / Wilson's storm petrel (Oceanites oceanicus) on snow, Antarctica, December.