Mortality in Wild Birds with some Observations on Weights

Abstract

SINCE THIS LABORATORY was opened in 1939, wild birds have been examined for the presence of infectious diseases which might be communicable to the poultry population.Material has been received from Scotland and the six northern counties of England, the area served by this establishment under the Poultry Stock Improvement Plans of the Department of Agriculture for Scotland and the Ministry of Agriculture, Fisheries and Food.Similar examinations have been carried out at the Ministry of Agriculture, Fisheries and Food, Central Veterinary Laboratory, Weybridge, Surrey, for the remaining counties of England and Wales (Keymer, 1958).During this time probably the most striking series of incidents was the occurrence of Newcastle disease (fowl pest) in poultry around the coasts of Scotland and its spread to Northern Ireland in 1949, and the subsequent demonstration of the presence of Newcastle disease virus in the carcases of a Gannet (Sula bassana) (Wilson, 195o) and Shags (Phalacrocorax aristotelis) (Blaxland, 1951), suggesting a possible direct connection between the disease in these birds and domestic poultry.Later experimental work showed Cormorants (Phalacrocorax carbo) and Herring Gulls (Larus argentatus) to be extremely resistant to artificial infection with Newcastle disease virus (J.E. Wilson, pers.comm.).In general, diseases in wild birds do not appear to be a serious threat to poultry in this country especially since the intensive methods of husbandry now in vogue preclude intimate contact between poultry flocks and free-living wild birds.Jennings (1 954, 1959) completed the first part of a survey supported by the B.T.O., and at the end of 1 959 we were asked to continue this work for the entire country.