HerpIndiana

Green Frog (Lithobates (Rana) clamitans)

Adult from Jefferson County

Description

Morphology: A large, green to olive colored frog with an obvious green face. There may be some darker dorsal mottling, but some individuals have none. In males, the tympanum is much larger than in the females (Minton 2001, 123). This frog's underbelly is mostly white with some darker mottling present in most individuals. banding is usually present on the legs. Dorsolateral folds are present.

Size: This species grows to around 3-4in SV length (Conant and Collins 1998, 561).

Larvae: A large olive-brown tadpole that usually grows to around 4in length. The tailfin is heavily mottled (Conant and Collins 1998, 578).

Eggs: Females lay up to 5,000 eggs in a film on top of the water (Minton 2001, 130).

Similar Species: The American Bullfrog (Rana catesbiana) is the most likely to be confused with this species. Green Frogs have a dorsolateral fold and Bullfrogs don't. Green Frogs also have more distinct banding on the hind legs than Bullfrogs. Bullfrogs grow much larger than Green Frogs as well.

Distribution

The Green Frog is found through much of the eastern United States and Canada (Conant and Collins 1998, 560).

The Green Frog is common throughout Indiana (Minton 2001, 129).

Activity

Green Frogs are, for the most part somewhat active year round. In southern Indiana they can be turned up under rocks and logs around seeps throughout winter. They are most active from March to October.

Breeding Season: Green Frogs typically start calling sometime during May and will continue breeding sporadically throughout the summer. The frogs rarely continue calling into August. After being deposited, the eggs take a few days to hatch and the tadpoles transform sometime during that fall or the following spring depending on how late in the year the eggs were laid (Minton 2001, 130).

Taxonomy

The Northern Green Frog (Rana clamitans melanota) is the only subspecies that occurs in Indiana. The Green Frog belongs to the genus Rana and is in the family Ranidae which is represented in Indiana by 8 different species.

Natural History

Habitat: This species can be found in virtually any aquatic habitat. They seem to prefer cool, clear, flowing streams and rivers, but they are also found in woodland pools, lakes, or even stagnant muddy marshes. Green Frogs are often turned up under rocks, logs, and leaf litter near the water's edge. They may also be seen sitting around the edge of small pools and ponds. When disturbed, this species will promptly leap into the water, giving off a high pitched yelp, and bury themselves into the leaf litter or mud. Green Frogs may be seen crossing roads or hopping around out in the open near permanent water on rainy nights.

Feeding: Green Frogs feed on a variety of invertebrates. They mainly feed on insects with spiders and mollusks being taken occasionally too. Green Frogs will ocasionally prey on small fish and frogs as well (Minton 2001, 130).

Breeding: In Indiana, this frog tends to breed in shallow permanent bodies of water such as woodland ponds and creeks. Amplexus occurs in shallow water and the eggs are fertilized externally by the males.

Call: Green Frogs have a distinct low-pitched single note call that is often likened to the plucking of a loose banjo string. The call occurs at irregular intervals.

Conservation: Green Frogs are wide spread and adapt well to habitat disturbances. While I have seen American Bullfrogs (Rana catesbiana) outcompete this species in some ponds, it does not appear to be a major threat to the stability of Green Frog populations overall.