Marine mammals use stars for navigation

Navigating in the open ocean is essential for seals and other marine mammals to move between foraging grounds that may be hundreds of kilometres apart. This is the first evidence that marine mammals, like humans, use stars to navigate in open water, say scientists.

The animals foraging trips can take several days and so they often find themselves in open water with no visible landmarks for nights on end. How these wild seals learn the relationship between a star and their feeding ground is still unknown.

The researchers think that marine mammals might use star paths, or "kaveingas" as Polynesian seafarers call them.
These people navigate by heading towards a star on the horizon until it moves too high to see, and then swap over to follow another star, and so on, guiding their way until dawn.
Seals, sealions and whales are often seen elevating themselves out of the water as they swim in open ocean. This act of coming out of the water vertically and staying above the surface momentarily, in the same way a human treads water, could allow marine mammals to set their course, the researchers speculate.

For more detailled information on BBC new see http://news.bbc.co.uk/2/hi/science/nature/7532867.stm