Marine predators follow mathematician’s theory to hunt prey efficiently

WASHINGTON - In a new research, a team of scientists has found that marine predators hunting randomly spaced prey do not themselves move randomly, in order to hunt efficiently, thus following a French mathematician’s theory.

According to a report in Natural History Magazine, the research has been done by David W. Sims of the Marine Biological Association in Plymouth, England, and colleagues.

For an efficient hunting strategy, the researchers recommend the “Levy walk,” which involves alternating clusters of short moves with much larger jumps-a pattern formulated by the late French mathematician Paul Pierre Levy.

Reasoning that Levy walks, often conceived as a series of horizontal moves, could also apply to aquatic predators hunting for prey at various depths, Sims’s team attached depth recorders to the bodies of thirty-one marine foragers from seven species.

The data revealed that basking sharks, bigeye tuna, Atlantic cod, leatherback turtles, and Magellanic penguins swim up and down in the water column according to a Levy pattern.

Two other species-small-spotted catsharks and southern elephant seals-do not.

An analysis of how swarms of krill and zooplankton change depth through time, combined with computer simulations of the movements and distributions of predators and prey, also confirmed that “Levy dives” beat purely random searches.

Although five adult basking sharks followed a Levy pattern, one juvenile that the team tracked for seven months did not, so according to Sims, Levy searches can also be learned. (ANI)