Seasonal patterns of reproduction and body condition in prairie voles (Microtus ochrogaster) on the Cumberland Plateau

The study was conducted within the 675.5 square mile area of Cumberland County, Tennessee, on the Cumberland Plateau. The objects of this study were: (1) to determine reproductive patterns of populations of prairie voles (Microtus ochrogaster) on the Cumberland Plateau, Tennessee, and (2) to determine fluctuations in body fat and adrenal size and weight in relation to seasonal changes and reproductive status. Animals were collected by kill trapping on sites within Cumberland County that supported moderate to high densities of prairie vole populations. An apparent decline in breeding of males was manifested by: (a) a decline in testicular weight, (b) a decline in seminal vesicular weight, and (c) a decline in the proportion of males judged fecund. The decline of testicular and vesicular weights, and proportion of fecund males was most marked during December. Female reproductive activity was gauged by the percentage of females pregnant in each monthly sample. Minimum sexual activity was noted in December when less than one fourth of the females were pregnant. Fat analysis indicated no significant difference in male and female (pregnant and nonpregnant) body fat content. Seasonal differences were absent also.