62 Ronald W. Mobley and Grover C. Miller 



tered more on taxonomic revisions and included works by Johnston 

 (1935), Lopex-Neyra (1943, 1952), Wardle et al. (1952, 1974), and Baer 

 (1954). The trematodes of sea birds were extensively studied by Linton 

 (1928), Yamaguti (1958, 1971) and Cable et al. (1960). Van Cleave 

 (1918, 1934, 1939, 1947), Perry (1942), Reish (1950), and Petrotchenko 

 (1958) provided excellent information of the taxonomy and biology of 

 the acanthocephalans of these birds. Recent contributions to sea bird 

 helminthology included those of Deblock (1966), Jones and Williams 

 (1967, 1968, 1969), Threlfall (1971), Ellis and Williams (1973), Williams 

 and Ellis (1974), Riley and Owen (1975), and Bourgeois and Threlfall 

 (1979). 



A variety of literature on the identification and ecology of the bird 

 hosts is available in publications by Bent (1921, 1922), Murphy (1936), 

 Roberts (1940), Palmer (1941), Robertson (1964), and Watson (1966). 



The objectives of our study were to (1) determine the gastrointesti- 

 nal helminth fauna of certain sea birds, and their prevalence and inten- 

 sity ranges; and (2) correlate differences in helminth fauna with aspects 

 of host biology such as feeding habits and geographical range. 



METHODS AND MATERIALS 



Eighty-five birds were collected between May 1977 and August 

 1979, including seven species of Procellariformes, one species of Peleca- 

 niformes, and two species of Charadriiformes. All were collected from 

 the Atlantic Ocean east of and adjacent to Oregon Inlet, North Caro- 

 lina. Twelve- or sixteen-gauge shotguns and either No. 2 or No. 4 high 

 velocity shot were used to collect the hosts. 



Wilson's storm petrels, Oceanites oceanicus, were attracted into 

 range using "chum" consisting of poultry offal. Fulmars Fulmarus gla- 

 cialis; shearwaters, Puffinus spp.; and gadfly petrels, Pterodroma spp., 

 were generally unresponsive to chum slicks but were occasionally 

 encountered in close proximity to commercial fishing vessels. Red-billed 

 tropicbirds, Phaethon aethereus, were collected singly near the collect- 

 ing vessel. Common terns, Sterna hirundo, and bridled terns Sterna 

 anaethetus, were collected either on the wing or as they rested on flot- 

 sam. After collection each bird was labeled with respect to time and 

 date, placed in an individual plastic bag, and put on ice. Hosts were 

 hard forzen within eight hours of collection and examined as soon as 

 possible, usually within 48 hours. Bird identifications were based on 

 Watson (1966). 



Each bird was incised midventrally from cloaca to sternum. The 

 alimentary tract, from gizzard to rectum, was removed intact to a glass 

 dish containing saline, where the tract was then longitudinally dissected. 

 The gut contents were agitated, rinsed, and allowed to settle. The super- 



