Horseshoe bats at Campbell Hide

Hi I visited Nagshead last Friday and was lucky enough to see boar and three horseshoe bats. Trouble is I'm not sure if they are Greater or Lesser Horseshoe.

I had a chat with Hugh (maybe Huw if you spell it the Welsh way) who was great. The bats were in the entrance to Campbell Hide so I was wondering if someone could measure the height of the 'Mind Your Head' sign or the beam above it so I can work out what size the bats are?

Have uploaded a couple of pics here:

http://www.flickr.com/photos/75603241@N03/7906454826/in/photostream

http://www.flickr.com/photos/75603241@N03/7906439992/in/photostream

I'd really appreciate it if someone could spare a minute to do that for me.

Many thanks in advance and thanks for a lovely day at Nagshead.

Gribbly