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We measured the activity of Peromyscus maniculatus, Clethrionomys gapperi , and Napaeozapus insignis using a sand transect in a forest in Quebec. Activity on each of 651 summer nights over 8 years was compared to the weather of each night. All three rodents were most active on rainy and on warm nights. C. gapperi and N. insignis showed increased activity on cloudy and moonless nights and when rain had not fallen for several nights. C. gapperi also increased activity with increased humidity. Variation in activity due to weather was slight and more likely associated with predator avoidance than with physiological restrictions.

Within a pattern of multi-annual fluctuations in small rodent abundance observed in New York State's Adirondack Mountains from 1971–1977, three species of hibernators ( Tamias striatus, Zapus hudsonius , and Napaeozapus insignis ) exhibited considerable year-to-year population stability in comparison with similar-sized non-hibernators. The comparative population stability of the hibernators coupled with their lower biotic potentials suggests that these relatively k-selected species should be separated in the r-K selection continuum from the more r-selected nonhibernating small rodents.

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During a live-trapping study in a woodland in central New York in June, 1955, a number of woodland jumping mice ( Napaeozapus insignis ) were caught. Of 21 captures of these mice over a five-day period, mice were torpid on nine occasions and active on twelve occasions. The minimum daily temperatures recorded for these five days at the weather station on the Cornell University campus ranged from 48° to 57° F. The area trapped was about 500 feet higher in elevation than the Cornell campus and temperatures were probably somewhat lower. In addition, three of the days were rainy, and on these days a greater percentage of mice were found torpid. The torpid mice were usually in the typical position previously noted by past observers. The snout was tucked between the hindlegs and the animal had assumed a ball-like shape. Other observers have noted that the tail was usually coiled like a watchspring in hibernating mice. Coiling of the tail was not always present in torpid mice in these observations. Awakening reactions were similar to those described by other writers. The animal, upon being warmed and handled, began to revive. Violent shaking usually accompanied this revival. The sense of balance seemed …