do bats hibernate?

[quinah]

We have a bat in our area (we call him bertie) I only ever see him at dusk in the late summer, and I can still hear him at night between 9-10.30 at the moment, but then he just seems to disappear till the next year, do they hibernate?

[New Forester]

You are lucky to be able to hear them -- they went off the top of my hearing some years ago... Yes, in temperate climates such as the UK they hibernate. In summer, they live in lofts or hollow trees -- yours could be in your own roof, or anywhere else within a couple of miles. You are probably seeing a good few more than one, of perhaps two or three species. In autumn (that is, soon...) they move to cellars, caves, big hollow trees or other sheltered sites where the temperature will never go below freezing. They roost there, and then when (and nowadays if) the weather turns, they hibernate. They will often fly on warmer nights through the winter. Some bats in temperate continental areas (N America, European mainland etc) may migrate instead of hibernate, but UK bats are not thought to do this much.

[football]

In Britain there are thirteen or fifteen species of bat. USA has the same number. There are all types of bat migratory / hibernate & combination of both. Depends on temperature & food sources as to what they do.

[New Forester]

Football - You're about right for UK bat species, though more are recognised from time to time. There are at least thirty species in Europe as a whole. However, I'd be extremely surprised if the US has so few species as 15. I've never been there, but I can think of about six straight off. I'd expect there to be 15 or so in any one place -- and it's a big, varied country. Having just checked on Google, one list gives the number for the US as 45. No doubt they too are recognising new species (for example, surely they'll turn out to have more than two species each of pipistrelle and long-eared or "big-eared" bat?). See http://www.batcon.org/discover/species/usspecies.html Incidentally, there are at least as many species of bat in the world as all the other mammals put together.

[football]

I stand corrected on the USA bit, nearer to at least 30 species. The Arctic is the only continent in the world with no bats because it's too cold for bats or insects.