Protecting and enhancing the natural values of Salt Spring Island and its surrounding waters


Bronze Frog

Bronze Frog


Lithobates clamitans (formerly Green Frog, Rana clamitans) is native to eastern North America and introduced to our area. These frogs breed in ditches, ponds, and marshes with permanent water and abundant aquatic vegetation. They are usually found close to water but may forage in fields and meadows during wet weather. Adults reach up to about 100 mm in body length. A fold on each side of the back (dorsolateral fold) that extends from behind the eye to about ¾ of the length of the body is diagnostic. The back and sides are green or bronze with irregular dark spots or flecks. The upper lip and side of face from the jaw line to the shoulder are light green. The underside is whitish or yellow, occasionally with some grey mottling on the upper portion. Males have a prominent ear drum, about twice the diameter of the eye, and a yellow throat.  Eggs are laid in warm water from late spring to summer during a prolonged breeding season. Eggs are small (1.5 mm in diameter) and in loose, floating masses containing up to about 5000 eggs. The masses are less than 30 cm in diameter and smaller than Bullfrog egg masses that are otherwise similar.  Tadpoles are olive green or brownish with numerous small dark dots with blurry edges on the back and sides. The tail is long with massive trunk musculature. The dorsal fin is low and starts behind the body-tail trunk boundary. Tadpoles resemble Bullfrog tadpoles but are smaller (up to 30 mm in body length, 90 mm in total length), have an oval shaped body that is widest behind the eyes when viewed from above, have spots with blurry edges, and lack any yellow colouration. Tadpoles usually overwinter before transforming into froglets.