Many excellent racing pigeon articles are available on the internet.  One very good  source is the below link.

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PIGEON HOMING: OBSERVATIONS, EXPERIMENTS AND CONFUSIONS
An Article by Dr. Charles Walcott
Laboratory of Ornithology and Section of Newrobiologh and Behavior, Cornell University, Ithaca, N.Y.

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Do Pigeons Spread Disease?

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Antibiotics – Don't Use Them.
Author,  Alan Wheeldon

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Avian Influenza ('Bird Flu')
A document by Dr. Gordon Chalmers

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