Potential effects of gapeworm (Syngamus trachea) on Greater Prairie-Chickens (Tympanuchus cupido) in Wisconsin

Greater prairie-chicken (Tympanuchus cupido) populations in Wisconsin were listed as state threatened following precipitous declines related to habitat loss and degradation, including the conversion of suitable habitat to... [ view full abstract ]

Greater prairie-chicken (Tympanuchus cupido) populations in Wisconsin were listed as state threatened following precipitous declines related to habitat loss and degradation, including the conversion of suitable habitat to agriculture. From 2013 to 2015, research was conducted to quantify nest and brood survival of prairie chickens in central Wisconsin. Female chickens were radio-marked and dead chickens were collected for necropsy. In 2015, one female prairie chicken necropsied at the National Wildlife Health Center in Madison, WI had a high intensity of gapeworm (Syngamus trachea), a respiratory parasite. Subsequently, we necropsied remaining prairie chicken carcasses to determine gapeworm prevalence. We suspected that gapeworm infection would be common in prairie chickens from central Wisconsin. Female adult gapeworms produce eggs in the trachea of birds, which are subsequently coughed up, swallowed then released in the bird’s feces. Infective larvae then hatch from eggs and are ingested by earthworms and other invertebrates which act as paratenic hosts. These invertebrates then are consumed by birds. We necropsied 13 birds and three (23%) were found to contain gapeworm. The intensities ranged from five to over 75 worms in a single bird. Gapeworm infection may influence the health of individual prairie chickens; however, additional research is needed to identify the effects of gapeworm on populations of prairie chickens in Wisconsin.