Ecology of Three Species of Peromyscus from Southern Missouri

Abstract

Extensive trapping in the Missouri Ozarks indicated that Peromyscus leucopus is an inhabitant of hardwood forest, P. maniculatus preferred grassland and P. boylii occurred only in the juniper-grass glades. The description and structure of Missouri glades are discussed, and the geographical range of the brush mouse in the state outlined. Analysis of stomach contents of P. boylii, P. leucopus and P. maniculatus revealed only slight differences among them in food habits. The type of food consumed on a seasonal basis reflected availability more than any other factor. The average daily water consumption of P. boylii, P. leucopus and P. maniculatus was approximately 3.5 cc, indicating a similarity in ad libitum water requirements. Consumption of water per gram body weight was smallest in P. boylii and greatest in P. maniculatus. The ability of three species to undergo dehydration and withstand a reduced net water ration were similar. Intraspecific behavior experiments indicated that for P. leucopus and P. maniculatus there is a marked social dominance by one male over another, while for P. boylii no distinct social hierarchy was evident. Interspecific behavior experiments demonstrated social compatability between P. maniculatus and P. boylii or between P. leucopus and P. maniculatus. P. boylii and P. leucopus were incompatible, with fighting occurring between males as a result of aggressiveness by P. leucopus. P. maniculatus, P. boylii and P. leucopus occur in separate habitats due to behavioral differences rather than detectable differences in the physiological factors considered. Competition between P. boylii and P. leucopus, which takes the form of overt aggressiveness, probably contributes to the sharpness in ecological distribution of the two species.