DISTANCE-TO-COVER AND THE ESCAPE DECISIONS OF AN AFRICAN CICHLID FISH, MELANOCHROMIS-CHIPOKAE

The risk to a prey individual in an encounter with a predator increases as the distance to protective cover increases. Prey should therefore initiate their flight to cover at longer distances from an approaching predator (i.e., sooner) and/or flee at greater velocities, as the distance to cover increases. These predictions were tested with an African cichlid fish, Melanochromis chipokae presented with a looming stimulus simulating an attacking predator. The fish varied their flight initiation distance as predicted, but there was no significant effect of distance-to-cover on escape velocity. Nevertheless, the cichlids appeared to choose a combination of flight initiation distance and escape velocity which ensured they reached cover with a constant temporal 'margin of safety'. © 1990 Kluwer Academic Publishers.