the bird’s stomach (Limona & Hoyo, 1992; Evans & Heiser, 2004). Grebes eat their own feathers and plant matter,
believed to act as retainers, keeping the fish bones in the stomach long enough for the acid to dissolve them (Piersma &
van Eerden, 2008). So instead of casting normal pellets, grebe cast pellets consisting mainly of water weeds and
feathers, together with some fish bones that have yet to be dissolved.