FLIGHT IDENTIFICATION OF EUROPEAN RAPTORS. By R.F. Porter, Ian Willis, Steen Christensen and Bent Pors Nielsen.

(1974) 1981 3rd edition. 8vo (158 x 254mm). Pp180. 248 b/w photographs of raptors in flight, illustrations by Ian Willis, red end-papers. Black boards, spine titled in gilt.

"The identification of the diurnal birds of prey is especially difficult. There is wide variation in plumage among some species, especially the eagles and buzzards, and in all species general outlines and wing positions are much affected by the prevailing conditions, by wind and light, and by the bird's behaviour at the time. Often, too, the birds are only sighted at long range, and the authors believe that when travelling extensively in Europe even the expert cannot hope to identify more than seventy percent of the raptors seen." This book arranges the 38 European raptor species into seven groups according to morphology, and describes what members of each have in common, and what they don't.