Fiona Reid is organising a trip to the remote Bosawas Reserve in northern Nicaragua in early January, primarily to catch bats and small mammals. It sounds like a very exciting destination, with very little known about the bats there. But a high diveristy is almost guaranteed: on her last batwatch trip to Nicaragua they caught over 40 species of bats! And there will be other cool stuff too.
If you are interested then you should contact Fiona and some more details are here http://www.fionareid.ca