Helminth parasites of the cattle egret (Bubulcus ibis) in Texas in relation to diet and geographical distribution.

During the summer of 199 the incidence of helminth infection of 30 cattle egrets, Bubulcus ibis, was examined. Bubulcus ibis were collected in equal numbers near Galveston, Texas; Hitchcock, Texas; and Kingsville, Texas. Egrets were collected during two sampling periods, 1 May 1979- 30 June 1979 and 1 August 1979 - 30 September 1979. Five cattle egrets were collected at each sampling area each sampling period. Parasites found were Micortetrameres cf spiralis, Apharyngostrigea cf simplex, Nephrostomum ramosum, Synhiamantus invaginatus, Clinostomum complanatum, Tetrameres cf cochleariae, Oxyspirura cf petrowi, Physaloptera cf sqaumatae, Amplicaecum sp., Stomylotrema sp., Cyclophyllidea sp.. Hypodectes mites were also found. Significant (P 0.05) differences in terms of incidence and intensity of infection were found between Kingsville and Galveston, and Kingsville and Hitchcock birds during the May-June collection period for N. ramosum and M. spiralis. The level of infection of both of these parasites was higher in Kingsville birds during the May-June period. The differences in infection levels are believed to be related to differences in the usage of orthopterans and amphibians as food items. The difference in food items in turn is believed to be related to availability.