Brown long-eared bat  (Plecotus auritus)

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.

1. Integrated Taxonomic Information System (ITIS) (October, 2009)
   http://www.itis.gov/
   
2. Schober, W. and Grimmberger, E. (1987) A Guide to Bats of Britain and Europe. Hamlyn Publishing Group Limited, London.
   
3. Bats and the Law - a quick guide. Bat Conservation Trust (August, 2002)
   http://www.bats.org.uk/
   
4. Morris, P. (1993) A Red Data Book for British Mammals. Mammal Society, Bristol.
   
5. The Bat Conservation Trust: Species Information Sheet - Brown Long-Eared Bat (August, 2002)
   http://www.bats.org.uk/pages/uk_bat_species.html
   
6. Altringham, J.D. (1996) Bats: Biology and Behaviour. Oxford University Press, Oxford.
   
7. Macdonald, D.W. and Tattersall, F.T. (2001) Britain's Mammals - The Challenge for Conservation. The Wildlife Conservation Research Unit, Oxford University. Available at:
   www.wildcru.org
   
8. People's Trust for Endangered Species: Brown Long-Eared Bats (August, 2002)
   http://ptes.org/index.php?page=141