Wheel-running during anoestrus and oestrus in the ferret.

Wheel-running activity was studied in female ferrets (Mustela putorius furo), during periods of anoestrus and oestrus, as well as after gonadectomy. During anoestrus wheel-running was restricted to the hours of illumination, but during oestrus extended into the dark period and was increased overall, with the number of wheel revolutions being doubled or trebled. In spayed females wheel-running was mostly limited to the light periods.