Literature References 

Coulton, L.E., Waran, N.K., and Young, R.J. 1997. Effects of Foraging Enrichment on the   Behaviour of Parrots. Animal Welfare 6 (4): 357-363.

Engebretson, M. 2006. The welfare and suitability of parrots as companion animals: a review. Animal Welfare 15 (3): 263-276.

Hoek, C.S. and Cate, C.T. 1998. Abnormal Behavior in Caged Birds Kept as Pets. Journal of Applied Animal Welfare Science 1(1): 51-64.

Kalmar, I.D., Moon, C., Meers, L.L., and Janssens, G.2007. Psittacine Birds as Laboratory Animals:Refinements and Assessment of Welfare. Journal of the American Association for Laboratory Animal Science 46 (4): 8-15.

Image References 

A bird cage sold in PetSmart which is a typical bird cage.n.d. PetSmart Store Support Group, Inc. Accessed March 25, 2013 from http://www.petsmart.com/product/index.jsp?productId=11147351&f=PAD%2FpsNotAvailInCA%2FNo.

An example of a feather picking parrot. n.d.African-Grey-Parrot.Com. Accessed March 25, 2013 from http://www.african-grey-parrot.com/African-Grey-Feather-Pluckng.aspx.

An ill parrot. n.d. Parrot Care Basics. Accessed March 26, 2013 from http://parrotcarebasics.com/wp-content/uploads/2009/11/SickAsAParrot05.JPG.

Pellets as a diet for parrots.n.d. PetSmart Store Support Group, Inc. Accessed March 26, 2013 from http://www.petsmart.com/product/index.jsp?productId=11535487&f=PAD%2FpsNotAvailInCA%2FNo.

Taken by Cioli, G./BowTie/Courtesy Jenny, S. Feeding Enrichment. n.d. I-5 Publishing, LLC. Accessed March 25, 2013 from http://www.birdchannel.com/bird-diet-and-health/bird-care/enrich-your-pet-birds-life.aspx.