Muskrat Predation of Native Freshwater Mussels in Shoal Creek, Alabama

Widespread decline of native freshwater mussels has increased their susceptibility to extinction from environmental factors such as competition, disease, and predation. Mammals, in particular Ondatra zibethicus (Common Muskrat), are well documented as major predators of freshwater mussels. We assessed the impact of Common Muskrats on the native freshwater-mussel community in Shoal Creek, AL. We surveyed 12.7 km of Shoal Creek for signs of mussel predation by Common Muskrats. Based on the species composition of observed shell middens, Common Muskrats foraged on all 6 native mussel species in Shoal Creek, including federally listed threatened and endangered species (Hamiota altilis [Finelined Pocketbook] and Pleurobema georgianum [Southern Pigtoe], respectively). Common Muskrats appeared to feed on native mussels based on their natural availability rather than exhibiting strong size-selective predation.