Lesser horseshoe bat  (Rhinolophus hipposideros)

Echolocation: detecting objects by reflected sound. Used for orientation and detecting and locating prey by bats and cetacea (whales and dolphins).
Hibernation : a winter survival strategy characteristic of some mammals in which an animal's metabolic rate slows down and a state of deep sleep is attained. Whilst hibernating, animals survive on stored reserves of fat that they have accumulated in summer. In insects, the correct term for hibernation is 'diapause', a temporary pause in development and growth. Any stage of the lifecycle (eggs, larvae, pupae or adults) may enter diapause, which is typically associated with winter.
Tragus: a soft cartilaginous projection extending in front of the external opening of the ear. In bats it is thought to aid in the location of prey by generating many echoes, but the precise way in which this works is unknown.
Ultrasound: sounds that are above the range of human hearing.

1. UNEP WCMC (Jan 2002):
   http://quin.unep-wcmc.org
   
2. Bat Conservation Trust fact sheets (Jan 2002):
   http://www.bats.org.uk/downloads/script/download.asp?d=Helpline&doc=Lesser_Horseshoe_bat.qxd.pd
   
3. UK Biodiversity Species Action Plan (Jan 2002):
   http://www.ukbap.org.uk
   
4. Schober, W. & Grimmberger, E. (1989) The bats of Britain and Europe. Hamlyn, London.
   
5. Gotch, A.F. (1979) Mammals, their Latin names explained. A Guide to Animal Classification. Blanford Press Ltd, Dorset.
   
6. Altringham, J. (1999) Bats, Biology and Behaviour. Oxford University Press, Oxford.