9317652 Morse Abstract Birds and mammals learn how and where to find food, but most people would assume that invertebrates such as spiders do not learn from experience, developing their adult foraging behaviors solely through maturation. Dr. Morse will test this assumption by examining the role of experience in the development of choice of hunting site ("patch choice") of the crab spider, a sit-and-wait predator on flowers. His previous research has established the importance of success in juvenile patch choice, because it affects the spider's chances of becoming an adult. Further, if one succeeds in becoming an adult, earlier patch choice may affect the chances of capturing enough prey to produce a clutch of eggs, which will differ markedly in size and resultant lifetime fitness with adult success. Dr. Morse has carefully worked out the relationship between adult foraging success and lifetime fitness of the crab spider, making it a uniquely suitable species for studying the role of juvenile learning on adult fitness, a problem on which virtually no information exists. Dr. Morse will focus on two aspects of the role of experience: the effect of juvenile patch choice on immediately subsequent choices, and the effect of such juvenile experience on choices subsequently made as adults. Experiments will be run both in field enclosures and in laboratory settings, carefully controlling for prey type and spatial and temporal distribution of prey.
