The Incidence of Lead Shotgun Pellets in Waterfowl (Anatidae and Rallidae) Examined in South-Eastern Australia Between 1957 and 1973.

Abstract

Data from the fluoroscopic examination of waterfowl (Anatidae and Rallidae) trapped at Lara, Vic., between 1957 and 1973 are summarized. The incidence of shotgun pellets in body tissues varied between species, and within age and sex groups; generally males contained more pellets than females, and juveniles fewer than adults. Larger species tended to contain proportionally more pellets than smaller species. Annual variations in pellet incidence were difficult to interpret, because birds examined before a shooting season contained pellets (presumably from the preceding seasons). Data from juveniles were of limited value since comparative large samples were not available after open seasons. Presence of pellets in body tissues seems to confer no disadvantage, since recovery rates, and distances travelled to recovery locations, were not significantly different for birds with or without pellets. Examination of gizzards revealed very few ingested pellets and the data did not suggest that lead poisoning was a potential mortality factor. It was concluded that fluoroscopic examination of waterfowl for pellet content offers little for the more effective management of the resource, since it provides, at best, post hoe information from birds whose source, and previous exposure to shooting, is generally unknown.