What is a caves temp when a bat lives in it?

Answer 1

Depends on location because caves generally settle at the mean annual air temperatures of their locations, but it's not a hard and fast rule but varies a little from cave to cave within their own region.

Bats respond to this, and prefer slightly colder caves for hibernating than they do for Summer roosts and nurseries, so tend to move from one site to another accordingly.

For a reasonably extensive cave in the UK - or one in similar climate in the US and elsewhere - the mean annual internal air temperature is typically around 50ºF (10ºC), and bats seem quite happy with this.

I think it's the Luray Caverns that are a prime US example. The cave is open as a show-cave in Summer, when it is deserted by the bats that hibernate in it over Winter, when the cave is then closed to visitors to protect the animals from disturbance. (Hibernating bats don't go into a complete coma, but will occasionally wake and feed in warmer spells.)