Helminth community structure and pattern in sympatric populations of black-bellied and fulvous whistling-ducks

Abstract

Helminth communities of 25 black-bellied (Dendrocygna autumnalis) and 25 fulvous (Dendrocygna bicolor) whistling-ducks from south Texas varied in composition, prevalence, dominance, and abundance. Twenty-eight helminth species were found, of which 20 occurred in each host species population. Twelve species co-occurred between host populations. Black-bellied and fulvous whistling-ducks averaged 3.0 ± 0.3 (SE) and 5.0 ± 0.4 species, respectively. Fifteen common species were found, of which 8 and 11 species commonly occurred in black-bellied and fulvous whistling-ducks, respectively. Four species (Apatemon gracilis, Tanaisia bragai, Sobolevicanthus gracilis, and Epomidiostomum uncinatum) were common in both host species. Prevalences varied in 4 of 8 helminth species co-occurring in both host species; 3 helminth species had higher prevalences in fulvous whistling-ducks. Black-bellied and fulvous whistling-ducks averaged 7.8 ± 1.4 and 44.8 ± 11.9 helminth individuals, respectively. Eleven of 15 common helminth species varied in abundance between host species populations; 4 species had higher abundances in black-bellied whistling-ducks and 7 had higher abundances in fulvous whistling-ducks. Our results suggest that although these duck species are sympatric, differences in feeding behavior may be most important in determining helminth community structure and pattern.