Key points are not available for this paper at this time.
(1) A trained male goshawk was used to arrange attacks on single pigeons and flocks, at brassica feeding sites and elsewhere. Captured pigeons were compared with shot samples from the same sites, using dry weight of the pectoralis minor muscle as an index of condition. Attacks on pigeon flocks at brassica sites were more successful than when the birds were feeding on grasslands and stubbles, possibly because of variation in pigeon condition.
Robert Kenward (1978) studied this question.