Population dynamics of two species of intestinal helminth in oystercatchers (Haematopus ostralegus)

Abstract

The cestode Micrasomacanthus rectacantha and the trematode Psilostomum brevicolle are the two most common intestinal helminths of oystercatchers, Haematopus ostralegus, on the Exe estuary, England. Each was present in 57 of 60 birds, in numbers ranging from 1 to 9833 and from 1 to 182, respectively. Cockles (Cerastoderma edule) were used as paratenic host by M. rectacantha and as second intermediate host by P. brevicolle. Over 90% of the transmission of M. rectacantha from intermediate hosts occurred in winter, between cockles and juvenile birds. Exposure to M. rectacantha was highest in cockles from muddy sites, where up to 80% of older cockles were infected with 1–14 larvae. Exposure to P. brevicolle was similarly high at one sandy site. Juveniles also made up > 90% of the birds present on the estuary in summer, when significantly more worms were gravid. Estimates based on the numbers of uterine eggs per individual P. brevicolle showed that 8 % of the total Exe population of oystercatchers (ca. 200) contributed 51% of the eggs to the estuary. The results implicate host age, host feeding preference, and host population structure as important factors determining variation in helminth abundance in birds.

The Ability of Oystercatchers Haematopus ostralegus to Compensate for Lost Feeding Time: Field Studies on Individually Marked Birds

“…Having failed to dislodge a shellfish from the bill, oystercatchers may even die of starvation (Hulscher 1988). Their shellfish prey may also be heavily parasitized (Goater et al 1995). Although the risks to oystercatchers of ingesting parasites are not known, observational evidence suggests that they may reject heavily parasitized prey (Hulscher 1996).…”

Individual variation in the competitive ability of interference‐prone foragers: the relative importance of foraging efficiency and susceptibility to interference

“…1996a; Hulscher 1996). This entails prolonged periods of foraging, and the use of areas where the risks of predation, parasitism and of accidents are likely to be elevated (Goater 1993; Cresswell 1994; Goater, Goss‐Custard & Kennedy 1995; Goss‐Custard et al . 1996a).…”

Cestodiasis in the Red Grouse in Scotland

“…Despite a growing interest in the epidemiology and ecological consequences of helminth infections in wild vertebrate hosts (reviewed by Grenfell and Gulland, 1995), there have been few field studies on the population biology of cestode infections in birds (Avery, 1969;Dick and Burt, 1971;Goater et al, 1995). In this paper, field data are presented on cestode infections in wild red grouse Lagopus lagopus scoticus from Scotland.…”