The Shelduck population of the Mersey area in summer, 1957-1963

Abstract

The purpose of this report is to show that the summer population of the Shelduck (Tadorna tadorna (L.)) in 1963, following the extremely hard winter, was not below average on the coasts of Lancashire, Cheshire, and North Wales. Counts of the Shelduck in the estuaries of the Rivers Mersey, Dee, Clwyd and Conway (hereafter referred to collectively as 'Area A') were first organised in 1957. The object was to find out how the totals for this area compared with the scale of moult migration recorded annually in Cheshire since 1950 (R. H. Allen and G. E. Rutter, British Birds 49:221-226. 1956 and later duplicated reports). Counts were made at the end of June, before migration commenced, and, from 1959 to 1962, again in mid-August when the moult-migrants had departed. The mid-August counts were abandoned after 1962 because the previous four years observations showed consistently that about nine out of ten adults migrated from Area A.