CAN AN EXPERIENCED PREDATOR OVERCOME THE CONFUSION OF SWARMING PREY MORE EASILY

Three-spined sticklebacks (G. aculeatus L.) which had previously fed on Daphnia in a high density swarm subsequently attacked a prey swarm (which had all known characteristics enhancing confusion) differently from fish fed equal numbers of Daphnia from a lower density swarm. Predators which had previously encountered low density prey hesitated longer before the 1st attack, attacked less and at a lower rate, and ceased hunting earlier than those fish that had previously prefed upon the high density Daphnia. Possible causes of the difference in attack behavior are discussed.