Diets of adult and chick Herring Gulls Larus argentatus argenteus on Alisa Graig, south-west Scotland

Abstract

The Herring Gull Larus argentatus, is widely distributed over the Holarctie region (Cramp & Simmons 1983), and, although in terms of breeding biology and behaviour is a relatively wellstudied species, its diet has received comparatively little detailed attention over much of its range. Some dietary studies have been made in Europe, e.g. Spärck 1951, Ehlert 1961, Harris 1965, Andersson 1970, Spaans 1971, Spitzer 1976, Mudge & Ferns 1982, but there has been little information on the diet of both chicks and adults during the breeding season (see Spaans 1971, Monaghan 1977). There is also some contradiction, one researcher having concluded that the diet of chicks is similar to adults (Threlfall 1968), while others have reported the contrary (Ehlert 1961, Spaans 1971).
\nThe aim of this study is to describe the food spectrum of adult and chick Herring Gulls in the Firth of Clyde area of south-west Scotland, by analysis of pellets, regurgitations and prey remains during a single season.