The influence of geographical location, host maturity and sex on intestinal helminth communities of the double-crested cormorantPhalacrocorax auritusfrom the eastern United States

Abstract

AbstractHere the intestinal helminth infracommunities of 218 double-crested cormorants (Phalacrocorax auritus) from 11 locations in Alabama, Minnesota, Mississippi and Vermont are documented. Trematode infections were present in 98% of hosts; 65% of cormorants carried cestode infections, 4% were infected with acanthocephalans and 66% had nematode intestinal parasites. Parasite infracommunities of hosts collected on wintering grounds had higher richness and diversity than did birds collected on breeding grounds. Differences in parasite richness and diversity between male and femaleP. aurituswere also detected, but not between immature and mature bird hosts. Parasite intensity did not differ by sex, maturity, or between breeding and wintering season. The most common parasite wasDrepanocephalus auritus(spathans), which is recognized as a disease agent that negatively impacts the catfish aquaculture industry in the US.Echinochasmussp. in double-crested cormorants is documented for the first time in the United States. We suggest that the differences observed among parasite infracommunities could be associated with the foraging distances travelled byP. auritusduring breeding and wintering seasons, which is limited by allocation of parental care during the breeding season.