Effects of Environmental Variables on Some Physiological Responses of Microtus Montanus under Natural Conditions (summary for 1976)
Multiannual cycles in population density are known for a number of microtine rodents. However, factors that govern various phases of the cycle are poorly understood. In other words, little is known to what degree environmental factors and physiological responses of the animals contribute to such cyclicity. The purpose of the present study was essentially fourfold: A. Characterization of environmental variables that might affect Microtus populations at three or four different times of the year. B. Investigation of growth, maturation, and reproductive activity of Microtus montanus under natural conditions. C. Study of maturation molts and seasonal pelage changes in Microtus montanus in relation to sex, age, and reproductive status. D. A correlation of the information obtained in #1-3 above. It is hoped that the results will help to elucidate causes underlying the multiannual fluctuations in population density of microtine rodents.