At least five species of cestodes, seven of trematodes, seven of nematodes, and two of acanthocephalans were found in Anas platyrhynchos platyrhynchos (L.) and Anas acuta (L.). Male and female adult and juvenile mallards harbored greater numbers of worms than did pintails. Adult females of both species had greater numbers of helminths per bird than did males. In addition, juvenile birds harbored greater numbers of parasites than did adults. The parasitic faunas of the two surface-feeding ducks, mallard and pintail, differed quantitatively despite their common habits. These differences were not a reflection of different diets but the suspicion is that mallards are more susceptible to parasitism than pintails. No serious cases of helminthiasis were found in the 101 mallards and 101 pintails examined in 1967 and 1968.
Stable Isotope Analysis of Northern Pintail (Anas acuta) Feathers Wintering on Junam Reservoir
