Townsend's Solitaire (Myadestes townsendi) can carry significant quantities of food items in its oral cavity, pharynx, or esophagus, but the internal anatomy enabling this behavior and its phenological details have not been described. Here I report on the presence of a sublingual pouch formed by an enlargement of the mucous membrane (epithelium) of the floor of the mouth in both sexes of breeding birds, which is absent in juveniles and non-breeding adults. The free tongue (in particular the paraglossum) appears to be used to remove food from, and perhaps to sweep food into, the sublingual pouch. Development of a food-carrying pouch is probably an adaptation related to provisioning of the mate and young.