Hyla of the Pine Woods — Part 5

Hyla femoralis Latreille

The male Cricket Frog does the singing. The yellow throat is inflated enormously. Cricket Frogs are easily discovered while they are singing, because they do not, like Pickering's Hyla hide under moss and grasses, but swell their throats while they are in full view on some water-plant or floating twig.

This minute frog offers a marked difference from the ordinary frog form, in that the part of the head anterior to the eyes is unusually prolonged. Outside of this, the most striking peculiarity of the frog is its rough skin. The back usually has elongated wart-like elevations, which are large, relative to the small size of the frog.

The range of variation in colour is great, and the changes are made rapidly. These frogs may have a colouring that is green, light red-brown, clay colour, or a brown so dark as to look black in general effect. The dark shades are taken on when the frogs are in dark situations, and especially when the darkness is combined with a low temperature and moisture; the lighter colouration is assumed under the influences of bright light, high temperature, and dryness.

The colour pattern of the Cricket Frog is a very definite one, but at any given time it may be present in whole or in part, or may not show at all. The pattern is made up of a triangular dark patch between the eyes (the point of the triangle directed backward), and three obliquely-placed oval patches of colour, one just back of the eye and the other two on the sides of the body. The triangle between the eyes may be outlined with light colour, either green, reddish, or yellowish, and this light colour is continued in a band from the backward-projecting point of the triangle along the line of the back, to the posterior end of the body. This band of colour is likely to be broad at its anterior and posterior ends and narrow at the middle of the back, in the region just between the two posterior oval colour patches of the sides. These patches of colour on the sides are also usually bordered with light.

The Cricket Frogs breed late, although they are more or less active all winter. Their chorus is loudest in late April and early May, and it is then that the eggs are laid, attached to grass blades or leaves in the water. At this time the Swamp Tree Frog chorus has disbanded and the Pickering's Hyla is singing only at night.

The development of this frog is less rapid than that of the Common Tree Frog, the Eastern Wood Frog, or the American Toad. The tadpoles (The tadpoles of Acris may be identified, on close scrutiny, by the following characeristics: The upper lip bears two rows of horny teeth; the lower lip has the same number. The teeth are not notched at their tips. The border of the lower lip is not doubled in at the angles of the mouth.) may be found in the water as late as August. The final transformation takes place in September. The young tree frogs--as well as the older ones--seek shelter from the cold under stones and leaves at the margins of their brook or marsh. However, they have no long-continued hibernation, but renew their activity whenever the sun is warm or the south winds blow.

THE SWAMP TREE FROG (Chorophilus nigritus Le Conte, Chorophilus feriarum Baird, Chorophilus triseriatus Wied, Cope, Batrachia of North America.

The Chorophilus material is confusing, and insufficient to settle any problems. Chorophilus nigritus, feriarum, and triseriatus were described originally as distinct species. O. P. Hay, in 1892, called all three one species, making the latter two subspecies of the nigritus form (see quotation following). Dr. Stejneger of the National Museum has identified a subspecies septentrionalis well represented by forms from the extreme North. I have allowed feriarum, triseriatus, and septentrionalis to stand as subspecies of nigritus. However, the whole subject is in need of investigation and is open to revision.

"Snout acuminate, width of head in length of head and body 2.8 to 3 times; heel reaching in front of orbit; size larger; colour leaden to fawn, with three rows of dark spots above, these sometimes united in continuous bands. South Carolina to Mississippi." (Nigritus.)

"Snout shorter; width of head in length 3-3.25 times; heel reaching to front of orbit; length of body in total length of hind leg from 1.4 to 1.7; colour ash or brownish, eyelids involved in median stripe, three parallel stripes above seldom interrupted. Eastern United States to Illinois. (Feriarum.)

"Snout drawn out; width of head in length 3.5 to 3.6 times; heel reaching only to tympanic disk; length of body in total length of hind leg 1.24 to 1.5 times; colour ash to brown, with three parallel dark stripes, median often forked behind, spot on each eyelid. New Jersey to New Mexico and Idaho." (Triseriatus.) (O. P. Hay. 1892.)