In a study of two congeneric rodent species, sex differences in hippocampal size were predicted by sex-specific patterns of spatial cognition. Hippocampal size is known to correlate positively with maze performance in laboratory mouse strains and with selective pressure for spatial memory among passerine bird species. In polygamous vole species (Rodentia: Microtus), males range more widely than...

The meadow vole (Microtus ennsylvanicus) and pine vole M_. pinetorum) are major pests in fruit orchards in the eastern U.S. These species damage trees by gnawing the bark or root systems during the winter months, thus, reducing the fruit yields or in many cases actually killing the trees. Orchard owners generally use an integrated pest management approach involving a combination of methods: (1)...

When isolated, pups of muroid rodents emit ultrasonic vocalizations, an indication that they are stressed by being alone and exposed to cooling temperatures. Rate of vocalizations is greatest at the end of their 1st week and beginning of the 2nd week, declines in the 2nd week as eyes open and thermoregulation becomes fully established, and ceases in the 3rd week. Young of 1 vole species, the pr...