Green Tree Frog

Hyla cinerea Daudin

Colour.—Dark brownish green, bright pea-green, or light greenish yellow. A band of white or metallic yellow extends from the most anterior point of the jaw, widens backward along the jaw, continues under the ear and along the sides, sometimes to the thigh, sometimes only half the length of the body. A dark band from the posterior border of the eye and through the ear extends as a border above this light band of the sides. Jaw dark below the light band. A similar light-coloured metallic band extends along the posterior margin of the tibia and is bordered by dusky colour below. Narrower light bands also on anterior margin of tibia, and on posterior margin of tarsus and of the arm. Ear bronze. Eye golden or bronze. Underparts light, unspotted. Green on sides of throat. Throat pale yellow.

Measurements.—One of our largest tree frogs, i.e. length 1 3/4 to 2 1/2 inches. Head 1/2 inch long in specimen of 1 3/4 inches length. Legs very long; length of leg to heel equals length of body forward to the end of the muzzle. Tibia much longer than femur. The whole leg is one and a half times length of head and body.

Structure.—Skin of upper parts fine and smooth in texture. Underparts granulated. Head very pointed; flat and broad between the eyes. Eyes large; not greatly elevated, but extending far at right and left; pupil elongated. Ear situated half its diameter from the eye, round, small (about half the diameter of the eye). A fold of skin over the ear to the shoulder. Legs extremely slender. Webs very short. Disks on fingers and toes well developed. Inner sole tubercle small.

Range.—Hyla cinerea is found in the southern United States both east and west of the Mississippi. It is reported from North Carolina, South Carolina, Georgia, Florida, Louisiana, Mississippi, Missouri, and Texas. It is also found in southern Illinois.

Colour.—Olive-brown, or green of yellow or blue tone. There is no conspicuous pattern of stripes or spots; there may be few or many inconspicuous, orange-yellow flecks of colour on the back. The vivid colour of the back extends on the sides of the throat under the jaw. The dark colour of the upper parts meets the white of the underparts abruptly instead of blending into it. Ear may be brown, with green centre. The large eyes show golden or bronze reticulations. The nostrils, which are not pigmented, appear red. Underparts white, sometimes yellowish on breast, throat, and sides.

Measurements.—Length 1 1/2 to 2 inches. Head 1/2 inch (in frog 1 3/4 inches) long. Length of leg to heel equals or exceeds length of frog forward to the eye. Tibia but slightly longer than femur.

Structure.—Skin unusually smooth. Underparts granulated, except throat region. Outline of head rounded, less pointed than in Hyla cinerea Daudin. Muzzle projecting slightly beyond jaw. Head relatively thick through, compared with Hyla cinerea. Distance between the eyes greater than width of eyelid. Nostrils nearer to the end of the muzzle than to the eyes; they are farther from each other and somewhat nearer the eyes than in Hyla cinerea. Ear medium in size, a distinct fold of skin over it from eye to shoulder. A fold across the breast. Proportions and characteristics of extremities like those of Hyla cinerea.

Range.—Hyla evittata has been reported only from the region about Washington, D. C., but is likely to be found also from Long Island Sound to Chesapeake Bay in regions near the coast.

The Green Tree Frog is perhaps the most beautiful tree frog of North America. Its slender form and smooth fine coat of green and gold certainly give it an air of distinction. It is more slender than any other North American tree frog. The slenderness is accentuated also by the lengthwise stripes of metallic white or yellow.

As to colouration, this tree frog has great ability to change from light to dark. The colour may be nearly black, or it may be so light a greenish yellow that the stripes can scarcely be distinguished. There is some variation in colour pattern; that is, the light bands on the legs may be narrowed or obsolete, the light band of the side may extend no farther than half-way instead of quite to the posterior end of the body, and the dark bands bordering the light ones may be distinct or wholly lacking. One tree frog (In possession of G. S. Miller, U. S. Nat. Museum.) found at Bay St. Louis, Mississippi, wholly lacked the stripes of the sides. This Hyla sometimes has a few small orange, blackrimmed spots on the back.

The legs are so long that, except when it is leaping or resting, the frog seems very awkward. In fact, it very often loses its dignified air and becomes extremely ludicrous in appearance. It is gentle and not easily frightened. In this it is like Hyla versicolor and Hyla gratiosa and radically different from some of the smaller North American Hylas, such as squirella, pickeringii, and regilla. When aroused, however, it becomes as active as any tree frog.