Cornell University. Laboratory of Ornithology (2016) Cornell Lab of Ornithology’s handbook of bird biology. Third edition. Edited by I. Lovette. Chichester, West Sussex: John Wiley & Sons, Inc. Available at: https://ebookcentral.proquest.com/lib/bangor/detail.action?docID=4572950.
Davies, N.B., Krebs, J.R. and West, S.A. (2012) An introduction to behavioural ecology. 4th ed. Oxford: Wiley-Blackwell. Available at: https://ebookcentral.proquest.com/lib/bangor/detail.action?docID=862786.
Gill, F.B. (2007) Ornithology. 3rd ed. New York: W.H. Freeman.
Scott, G. (2010) Essential ornithology. Oxford: Oxford University Press. Available at: https://ebookcentral.proquest.com/lib/bangor/detail.action?docID=1507496.
Sturkie, P.D. (2015) Sturkie’s avian physiology. Sixth Edition. Edited by C.G. Scanes. London: Elsevier/Academic Press. Available at: https://ebookcentral.proquest.com/lib/bangor/detail.action?docID=1727289.
Sutherland, W.J., Newton, I. and Green, R. (2004) Bird ecology and conservation: a handbook of techniques. Oxford: Oxford University Press. Available at: https://doi.org/10.1093/acprof:oso/9780198520863.001.0001.
Svensson, L. (2022) Collins bird guide. London: William Collins.
