Maniculatus Bairdi Research Articles

Behavioral, Seed Preference and Habitat Selection Experiments with Two Sympatric Peromyscus Species

The woodland white-footed mouse Peromyscus leucopus noveboracensis cooccurs with the prairie deermouse P. maniculatus bairdi in old fields and prairies of southern Wisconsin. In order to examine possible mechanisms of this coexistence, fieldcaught individuals of both species were brought into the laboratory for testing. In a seed preference test in which mice were offered two species of old-field grass seeds and two species of native prairie grass seeds, all the mice preferred the old-field grass seeds. Neither species favored either habitat (field or woods) for activity during two 0.5-hr observation periods or for foraging. However, P. m. bairdi removed significantly less food from the woods habitat than did P. 1. noveboracensis and there was a significant difference in preferred nest location, with P. m. bairdi nesting primarily in the field and P. 1. noveboracensis in the woods. In 20 paired behavior trials, P. m. bairdi was dominant in two, P. 1. noveboracensis in 12, and there was mutual avoidance in six. The results suggest that interference competition may, in part, account for the distribution patterns of these species.

Diurnal patterning of eight activities in 14 species of muroid rodents

The diurnal patterning of locomotion, stereotypy, grooming, eating, drinking, sleeping, postural readjustment, and inactivity was studied in 14 species of muroid rodents in the laboratory using a visual observation technique.Microtus canicaudus, M. montanus, M. ochrogaster, andM. pennsylvanicus exhibited acyclic activity patterns, whilePeromyscus eremicus,P. gossypinus, P. leucopus, P. maniculatus bairdi, P. polionotus, Calomys callosus, Mus musculus, andOnychomys leucogaster displayed nocturnality in their behavioral patterning.Rhabdomys pumilio exhibited crepuscular activities andNeofiber alleni displayed a complex pattern of nocturnality. Species differed in total amount of time spent per day for all activities but eating. The acyclicity ofMicrotus species appears to be related to high metabolic rates and a semifossorial life-style.

Surgical anesthesia of seven rodent species with chloral hydrate

The use of pentobarbital as an anesthetic for animals in the genera Microtus and Peromyscus often results in high mortality rates. Chloral hydrate was administered in various dosages to adult male M. montanus, M. ochrogaster, M. pennsylvanicus, P. eremicus, P. leucopus, P. maniculatus bairdi, and P. polionotus in order to determine a safe, injectable anesthetic and dosage for performing lengthy surgery with these rodents. Dosages of 0.63 mg/g, 0.70 mg/g, and 0.77 mg/g were administered intraperitoneally and the presence or absence of palprebral and withdrawal reflexes were recorded at specified post-injection intervals. Chloral hydrate appears to be a safe and useful anesthetic for P. leucopus, P. m. bairdi, and P. polionotus at optimal dosages of 0.77 mg/g, 0.63 mg/g and 0.70 mg/g respectively. No safe acceptable dosage could be determined for any of the other species as considerable mortality resulted in response to any dosage.

Wild caught vs inbred mouse strains: Differences in wheel-turn avoidance learning

Three Bar Harbor inbred mouse strains; C57BL/6J, C3H/HeJ, and DBA/2J, and two wild caught but laboratory bred Peromyscus strains; P. leucopus and P. maniculatus bairdi, were compared over 8 days of acquisition training on a wheel-turn avoidance task. In the acquisition of the conditioned avoidance response, the Bar Harbor inbreds did not differ but were, as a group, significantly better than the wild caught strains. Differences in activity rate were also apparent, but do not account for the differences in avoidance performance.

Temperature Selection in Peromyscus and Laboratory Mice, Mus Musculus

Three kinds of Peromyscus and the laboratory mouse, M. musculus , maintained under constant temperature conditions, were tested in a horizontal temperature gradient with floor temperatures ranging from about 5 to 45° C. White-footed mice ( P. leucopus noveboracensis ) and laboratory mice had the highest selected temperatures and the lowest variability in the selection response (32.4°, sd = 1.3°; 31.8°, sd = 2.5°), while forest deer-mice ( P. maniculatus gracilis ) and prairie deer-mice ( P. maniculatus bairdi ) had the lowest mean selected temperatures and the greatest variability in response (29.1°, sd = 4.7°; 25.8°, sd = 5.2°). The ecological and taxonomic implications of these differences are discussed.