A few silver-haired bats hibernate in caves in Indiana, but otherwise silver-haired bats are found in Indiana only during spring and fall migrations (March through early June; and late September through November).
However, Whitaker & Rissler (1992) estimated that about 900 northern myotis hibernate in tiny cracks in this mine.
A few big brown bats hibernate in caves and mines in winter, usually near the entrance in small numbers.
It is not clear why Indiana myotis continue to do so well at Wyandotte Cave when the temperature in the areas where the bats hibernate is about 10[degrees] C, whereas their preferred hibernating temperature is about 2-6[degrees] (Hall 1962).
Madagascan fat-tailed dwarf lemurs hibernate during the winter, even though daily temperatures often top 30[degrees]C (86[degrees]F).
The animals appear to exploit their tropical conditions to hibernate with an energy-saving strategy not seen before in hibernators.
The researchers found that the lemurs hibernate from April to October, the dry season in Madagascar's winter.