Three species depicted, from left to right: Arctic tern (Sterna paradisaea), Bar-headed goose (Anser indicus) and Bar-tailed godwit (Limosa lapponica).
All are record holders in migration. The Arctic tern on the left makes the longest migration of any animal. For some individuals this means a 90 000 kilometre trip every year as they fly from the North pole to the South pole and back. More ‘common’ are yearly distances of about 70 000 km. They fly such long distances to take full advantage of both Arctic summers, when the sun doesn’t set for almost 6 months. By timing their migration perfectly, they take full advantage of this phenomenon on both the poles, thus catching more sunlight hours than any other creature on earth.
The Bar-headed goose makes the highest migration of all, flying at altitudes of around 5000 metres when they cross the Himalaya, at night, and only in a couple of hours. Some geese take it up higher, flying at up to 6500 metres, and some second hand reports even tell of the birds flying over Mount Everest – 8800+ metres. Air at that altitude is so cold that human skin would instantly freeze and contains only a fraction the amount of oxygen at sea level. There are winds that push up and against the mountains which could give the geese a ride up so to speak, but surprisingly the geese avoid these on purpose. They always wait for the wind to die down completely before they fly.
Last but not least is the Bar-tailed godwit. They have a worldwide distribution, migrating from the northern tundra to their tropical feeding grounds in Africa, Southern Asia or Oceania each year. One female of this species holds the record for longest recorded non-stop flight for any bird. She flew from Alaska all the way to New Zealand, 11500 kilometres, without ever stopping to feed or rest, completing the journey in nine days.