I've just been back to the UK courtesy of a €35 return flight with Ryanair. For my in-flight reading I took 'Raising Chickens for eggs and meat' by Mike Woolnough (ISBN 978-1-904871-42-2) which I would say is essential reading for any new poultry keeper -an excellent and very thorough book.
Quoting from his chapter on Breeding he says "You should never ever keep a few hens with several cockerels. The poor girls have to run the gauntlet of the males to get to their roost at dusk, which is the favourite mating time for roosters, and it invariably leads to mass gang rapes that can leave the girls in a terrible state."