The following bibliography has been generated by bringing together all references provided by our content partners. There may be duplication.

References

• 1. National Biodiversity Network Species Dictionary (July 2002) http://www.nhm.ac.uk/nbn/
• 10. NFU Countryside (July 2002) http://www.nfucountryside.org.uk/news/showarchivenews.asp?newsid=425
• 11. RSPB (2003) The population status of birds in the UK http://www.rspb.org.ukImages/5_20625.pdf
• 2. Mullarney, K., Svensson, L., Zetterstrom, D., & Grant, P.J. (1999) Collins Bird Guide. HarperCollins Publishers Ltd, London.
• 3. Environment Agency (1998) Species and habitats Handbook. The Environment Agency, Bristol.
• 4. Greenoak, F. (1979) All the birds of the air; the names, lore and literature of British birds. Book Club Associates, London.
• 5. Walters, M. (1994) Eyewitness handbooks: Birds eggs. Dorling Kindersley, London.
• 6. RSPB Chough research (July 2002) http://www.rspb.org.ukwildlife/default.asp
• 7. RSPB (July 2002) http://www.rspb.org.uk
• 8. Bruce Wilmore, S. (1977) Crows, jays, ravens and their relatives. David and Charles (Publishers) Ltd, London.
• 9. Lack, P. (1986) The Atlas of Wintering Birds in Britain and Ireland. T. & A. D. Poyser Ltd, Calton.
• B., Bruun., & S. Baha El Din.   (1985).  Common Birds of Egypt, The American University in Cairo Press, Cairo..  
• BirdLife International 2009. Pyrrhocorax pyrrhocorax
• Flower (1938) Furter notes on the duration of life in animals. IV. Birds. Proc Zool Soc London, Ser. A:195–235.
• Gill, Frank, and Minturn Wright. 2006. Birds of the World: Recommended English Names. ix + 259
• M., Tharwat.   (1997).  ‘Birds Known to occur in Egypt’, National Biodiversity Unit, no. 8, Egyptian Environmental Affairs Agency, Cairo..  
• Madge, S., & Burn H.   (1994).  Crows and Jays: A guide to the Crows, Jays and Magpies of the World.   New York: Houghton-Mifflin.
• R., Porter., & D. Cottridge.   (2000).  Birds of Egypt and the Middle East, The American University in Cairo Press, Cairo..  
• Reid et al. (2003) Age-specific reproductive performance in red-billed choughs Pyrrhocorax pyrrhocorax: patterns and processes in a natural population. J Anim Ecol, 72:765-776.
• S., Baha El Din., J. Hobbs., W. Mullie., S. Goodman., & P. Meininger.   (1989).  The Birds of Egypt, Oxford University Press, New York..