The taxonomy and distribution of the helminth parasites of some Welsh birds, with observations on their dissemination

Between August, 1960 and December, 1963, more than five hundred and seventy-six birds representing twelve orders, thirty families and seventy-nine species were examined for helminth parasites in the County of Pembrokeshire. The overall infection was 61.4% and only twelve species were uninfected. The material recovered consisted of eighteen species of trematodes, forty-three species of cestodes and seventeen species of nematodes. Two new species are described, Choanotaenia larimarina Elce, 1962 and Gymnophallus numenii sp. nov. There are thirty-seven new host records for western Europe. Three species are new to Europe and five species are new to Britain. Forty-four new host records for Britain are recorded and thirty-two species are recorded for the first time in Wales. The incidence of helminths is related to the host's diet and the ecological background. A survey was made of the helminths in domestic birds in Pembrokeshire, both by faecal examination and by post-mortem. The most common parasites were the nematodes Haterakis gallinarum (Schrank, 1788) - 73.9%, Capillaria obsignata Madsen, 1945- 45.05%, and Asacaridia galli (Schrank) 1788) - 35.1%. The results are compared with recent surveys by other workers and differences are due to this work being based on field tests and not the more usual laboratory postmor toms. Infective eggs of the above species were fed to selected wild birds, principally rooks (Corvus frugilegus L. ) and jackdaws (Corvus nomedula L. ), which were maintained on a normal and on a Vitamin A deficient diet. Wild birds do not act as hosts to poultry helminths and their significance as disseminators is limited to infected droppings. Dissemination of eggs on feathers and claws is difficult to estimate. The life cycle of Capillaria resecta (Dujardin, 1843) was attempted to assess Madsen' s suggested synonymy with c. anatis (Schrank, 1790). Circumstantial evidence indicates that the species are not synonymous.