Food Habits of the Green Frog, Rana clamitans, before and during Metamorphosis

One hundred forty-four Rana clamitans tadpoles were collected during April and May 1963 and September 1963 through March 1964 in southern Illinois. The larvae of the April and May collections were approaching or passing through metamorphosis; they exhibited no alteration of diet, even during the initial stages of metamorphosis. However, the tadpoles did fast from approximately the time the forelimbs broke through the body walls until their tails were about absorbed. Water samples were taken with each of the September through March collections. The kinds and numbers of organisms ingested by the tadpoles were proportionally reflected in the water samples; this correlation was statistically significant. It was concluded that green frog larvae are fortuitous and indiscriminate feeders with no apparent food preferences. Premetamorphic tadpoles appear to feed continuously, even in winter.