Intestinal Helminth Communities of Grey Partridge Perdix perdix and Common Pheasant Phasianus colchicus in Poland

SIMPLE SUMMARY: The presence of intestinal parasites such as nematodes, cestodes, and trematodes is a serious problem for programmes for the conservation of partridges and pheasants, mainly involving the breeding of these birds and their release into the natural environment. These parasites can cause disease in these birds, whether farmed or free-living. The aim of this study was to describe the morphology of parasitic worms in the partridge, native to Poland, and the introduced pheasant, and to determine the level of infection of these birds with intestinal parasitic worms. The study showed that partridges are infected with several helminth species that had not previously been recorded in this species in Poland. Pheasants are more often infected by intestinal nematodes than are partridges. These worms can negatively affect the condition of partridges and increase their risk of infection with pathogenic protozoa. The results of parasitological examination should be used to develop programmes for diagnosis and monitoring of parasitic infections in order to keep flocks free of parasites. ABSTRACT: The aim of this study was to describe the morphology and means of identification of helminths in native partridges (65) and introduced pheasants (32) in Poland and to determine the level of intestinal infection of these birds by helminths using parasitological and ecological indices. The birds were acquired during the hunting season in the years 2015–2017. Nematodes, Capillaria phasianina, cestodes, Railietina friedbergeri, and one trematode, Brachylaima sp. were recorded for the first time in partridges in Poland. Our findings indicate that parasites are more prevalent in pheasants (prevalence 70.4%) than in partridges (prevalence 50.0%). The component community and infracommunity of parasites of partridges are more diverse (Simpson’s diversity index: 0.63 and mean Brillouin diversity index: 0.10 ± 0.17) and less dominated by a single parasite species (Capillaria sp., Berger-Parker dominance index: 0.53) than the pheasant parasite community (Simpson’s diversity index: 0.07, mean Brillouin diversity index: 0.005 ± 0.02, dominant species Heterakis gallinarum, Berger-Parker dominance index: 0.96). There were statistically significant differences between partridges and pheasants in the Brillouin diversity index and in the prevalence of Heterakis gallinarum (55.6% in pheasants vs. 19.0 in partridges). There were significant differences between wild and farmed partridges in the prevalence of infection by Capillaria sp. (4.3% vs. 37.5%) and H. gallinarum (39.1 vs. 6.2%). In conclusion, the pheasant was shown to be a reservoir, carrier, and shedder of nematodes, which may increase the risk of infection in partridges.