Feeding ecology and laboratory predatory behavior toward live and artificial moving prey in seven rodent species

The present research related the feeding ecology of seven rodent species to the reactions of laboratory-reared and prey-inexperienced members of each species both to live prey and to an artificial moving stimulus predicting food pellets. Feeding ecology was determined by the degree of carnivory, based on reported stomach contents and observations of feeding. Experiment 1 assessed predatory reactions to a live cricket placed in each animal’s home cage. Killing and latency of eating the cricket were directly related to the degree of reported carnivory on moderately fast-moving arthropods. Experiment 2 examined behavior toward a rolling ball bearing that predicted delivery of food. Average percentages of trials with approach or contact of the bearing, and the conditional probability of a mouth contact were all positively related to the degree of reported carnivory and to cricket predation in Experiment 1. In addition, the topography of ball bearing contact for a species often resembled its topography of cricket contact. We conclude that (1) rodent predatory behavior can be studied in the laboratory using appropriate artificial stimuli and prey-inexperienced subjects, and (2) the predatory behavior of a species is based on underlying appetitive organization related to carnivory, including differential sensitivity to stimulus movement, motor preorganization, and susceptibility to conditioning. This appetitive organization appears to influence responding to both live and artificial prey.