Grand Teton National Park Report
Several microtine species exhibit multiannual fluctuations in population density. These fluctuations have been described as occurring with sufficient regularity to be called "cycles". This phenomenon has been known since anitquity. However, despite the extensive work that has dealt with this problem. the facts underlying these fluctuations remain largely unknown.
Pinter, Aelita J.
"Effects of Environmental Variables on Some Physiological Responses of Microtus montanus Under Natural Conditions,"
University of Wyoming National Park Service Research Center Annual Report: Vol. 3
, Article 11.
Available at: http://repository.uwyo.edu/uwnpsrc_reports/vol3/iss1/11