A reduction in numbers of birds of prey in France.

Abstract

In the past five years a summer holiday has been spent in France three times in early summer and twice in late summer, on the following dates:

1960 : 7-22 May (16 days); 1961 : 27 May - 10 June (15 days); 1962 : 9 - 15 and 23-28 August (13 days); 1963 : 3 - 18 August (15 days); 1964 : 14 - 25 May (12 days).

On each occasion a special note was made of all raptors seen. The results, although referring to relatively few data, seem to be worth placing on record as confirming the decline in numbers of these birds. Both J.V. Boys and K.D. Smith, who know the country well, have informed me independently (in litt.) that they had noticed a marked reduction in the numbers of raptors in 1963. More recently Terrasse (1964) has demonstrated that there has indeed been a considerable reduction in many species in recent years.

Recent changes in the status, and the reasons for the changes, of birds of prey in Europe have been discussed by Ferguson-Lees (1963). Zweeres (1963) has shown that reductions in some species has taken place in Holland. It has been shown (Ash 1960) that a major decline began in 1956 for a number of species in southern England, and the general decline in Britain in relation to the use of pesticides is reviewed by Cramp (1963). More particularly, Ratcliffe (1963) related the great decrease in Peregrine (Falco peregrinus) numbers in Britain to the use of toxic chemicals, and Moore and Ratcliffe (1962) and Moor and Walker (1964) have demonstrated the presence of pesticidal residues in the eggs of Peregrines and Golden Eagles (Aquila chrysaëtos) from Scotland.