Pine Barrens Treefrog
PINE BARRENS TREEFROG
Photo Credit: John Jensen
SCIENTIFIC NAME: Hyla andersonii (Baird)
DESCRIPTION: Adults small (about 3.8 cm [1.5 in.] long), plump, and green, with round, expanded toepads for climbing. Back and upper surfaces of legs pea-green, but may become dark olive-green under certain conditions of stress or weather. Sides with chocolate-brown to plum-colored band extending from nostril to hind limb that is delineated from green dorsum by a narrow, lemon-yellow border. Belly skin granular and white. Armpits, inside surfaces of hind legs, and lower sides have several bright yellow-orange spots that are usually concealed unless frog is moving (Gosner and Black 1967). Females slightly larger than males; recently transformed and young frogs identical to adults. Call consists of a series of high-pitched “quanking” notes repeated rapidly in sequence about 0.4 seconds apart for several seconds duration. Tadpoles up to 3.8 centimeters (1.5 inches) long and dark olive with black spots scattered over back. Belly greenish yellow. Tail musculature, and to a lesser extent the tail crests, with well-defined dark blotches and spots coalesced along the upper sides of the tail musculature to form a distinctive black line with irregular borders beginning just behind the body and progressing uninterrupted about halfway down tail (Means and Longden 1976).
DISTRIBUTION: Discontinuous in Atlantic Coastal Plain from
HABITAT: Hillside seepage bogs along gently sloping, small stream valleys typical in
LIFE HISTORY AND ECOLOGY: Males call from April to September. Tadpoles have been collected from early May to the last week in August. By the end of September, all larvae have probably transformed. Based on laboratory growth rates, larvae of one summer are capable of reaching adult size by the next, but this is not confirmed in the field. Males call from low perches (ground level to about 1.2 m [3.9 ft.] high) in vegetation surrounding breeding sites. Females deposit 200 or more eggs in batches of four to nine while amplexed with a male that fertilizes the eggs as they are extruded (Means and Longdon 1976). After hatching in three to four days, larvae soon begin an aquatic life grazing on algae and other plant matter. The frogs and tadpoles are very sensitive to changes in their environment. Attempts to rear tadpoles in captivity in tap water or even in water from the habitat often are unsuccessful. Captive adults that are especially well cared for usually die after a few months or less. Choruses rarely exceed 10 males. A locality having audible males at one part of the breeding season may be silent at another, even though the species is calling elsewhere (Means and Moler 1979). Most knowledge based on information obtained at breeding sites found by locating calling males. This represents only a fraction of the life history and ecology of the species. Little known of the ecology of nonbreeding adults.
BASIS FOR STATUS CLASSIFICATION: The remarkable distribution of disjunct populations makes it a subject valuable to the study of biogeography and evolution (Means and Longden 1976). Also, the Alabama-Florida populations differ significantly from those of the Atlantic Coastal Plain in aspects of morphology, ecology, call structure, and isozymes (Karlin et al. 1982). The ecology, distribution, and habitat suggest that the species was formerly more widespread during milder, wetter climates. Living populations could be considered “physiological relicts,” possibly best adapted to some Pleistocene climates. Local populations are subject to extirpation. Of 10
Author: D. Bruce Means