Cricket predation by the northern grasshopper mouse

Abstract

In a series of three experiments the development of predation and the relationship of predation to feeding were explored using the grasshopper mouse-house cricket predator-prey system. In Experiment One eight male mice were observed throughout a period of increasing experience with live prey, i.e., crickets. This group of mice was subsequently compared with a group of eight mice receiving no prior experience with crickets. All mice killed the first cricket they were given and 13 of the 16 mice tested consumed that cricket. Experience with prey resulted in more efficient killing reflected in briefer attack times. In Experiment Two the relationship of predation to feeding and the potential effects of experience on this relationship were investigated. Eight mice experienced with cricket prey and eight mice without such experience, all with ad lib access to their standard diet, were observed while preying on crickets presented successively. All mice initially killed and ate crickets and then continued to kill crickets which they did not consume. Results supported the view that the regulation of killing is at least partially independent of the mechanisms regulating feeding. Arguments that killing by satiated predators is a result of the “irritating” presence of prey were addressed in Experiment Three. Mice were required to leave a familiar home area to hunt in an adjoining foraging area where crickets were placed in containers and were not visible to mice. Killing without subsequent feeding was again observed providing further support for a view of killing not entirely regulated by feeding mechanisms.