Under-Ice Observations of Wintering Sites of Leopard Frogs

Leopard frogs (Rana pipiens Schreber) hibernating in an ice-covered pond in Ontario, Canada, were found to rest in small pits apparently excavated by the frogs. Frogs were sometimes lightly covered with silt and all were capable of some movement including swimming. This habit keeps the frogs from being buried in anoxic mud, but increases their exposure to predation by fish, such as trout. Observations were made using SCUBA under the ice.