Animal Foraging Tactics Never Grow Old: Pattern Used for 50 Million Years

If something works there's no need to fix it, and animals take that to heart when it comes to foraging techniques. Scientists have discovered that animals have used the same method to search for food that's in short supply for at least 50 million years.

The researchers first made the discovery after analyzing fossilized sea urchin trails from northern Spain. These sea urchins lived on the deep sea floor around 50 million years ago and the deep trails were preserved in rocky cliffs. They found that, surprisingly, the tracks reflect a search pattern still used by a range of creatures today.

"How best to search for food in complex landscapes is a common problem facing all mobile creatures. Finding food is a timely fashion can be a matter of life or death for animals-choose the wrong direction to move in often enough and it could be curtains," said David Sims, lead author of the new study, in a news release. "But moving in a random search pattern called a Levy walk is mathematically the best way to find isolated food."

In fact, modern animals that include sharks, honeybees, albatrosses and penguins all search for food according to this mathematical pattern. It's a random strategy made up of many small steps combined with a few longer steps. Although the Levy walk is random, it's the most efficient way to find food when it's scarce.

"Finding the signature of an optimal behavior in the fossil record is exceedingly rare and will help to understand how ancient animals survived very harsh conditions associated with the effects of dramatic climate changes," said Sims. "Perhaps it's a case of when the going got tough, the tough really did get going. The patterns are striking, because they indicate optimal Levy walk searches likely have a very ancient origin and may arise from simple behaviors observed in much older fossil trails from the Silurian period, around 440 million years ago."

The findings are published in the journal Proceedings of the National Academy of Sciences.