Hyla of the Pine Woods — Part 4

Hyla femoralis Latreille

At other times the change from dark to light shows no green colour, but warm tones of brown instead. In this case the frog becomes a delicate unspotted fawn colour as the last stage in the series. Or the change may be effected displaying only soft shades of grey. In all dresses, the frog is an unusually attractive one in its colouration. In the change from dark to light, or the reverse, the ear and eye respond also to the given stimuli. The spot under the eye shows a considerable range of colouring; it may be white, or some shade of yellow or green. When light-coloured, the frog displays metallic reflections, especially on the forearms and tibiae. In this light dress, all spots and marks are obliterated, except the heavy black blotch over the arm, the white spots under the eye and around the base of the arm, and a few black spots or specks on the sides. These seem to be permanent parts of the colour pattern.

Acris gryllus Le Conte. (Cope says that there are two subspecies: A. g. gryllus, found from North Carolina to Florida, and A. g. crepitans, found north of this as far as New York. The two subspecies differ but slightly and the division is of doubtful validity.

"Hinder foot less tarsus less than half the length of the head and body; dermal tubercles larger; posterior femoral stripes less distinct." (A. g. crepitans.)

"Hinder foot less tarsus longer than half head and body; dermal tubercles smaller; femoral stripes very distinct." (A. g. gryllus.))

Structure; Skin rough and warty. Head pointed, long from eyes to end of muzzle. The ear is indistinct; one-third the diameter of the eye. There is a fold across the breast and a curving fold over the ear from eye to shoulder. The foot is fully webbed. The inner and outer sole tubercles are both present, though small. The tubercles under the joints of the toes are fairly prominent. The disks on fingers and toes are so small that they are scarcely noticeable. Underparts granulated posteriorly only.

The most conspicuously active of our small tree frogs is the Cricket Frog, a tree frog with wholly terrestrial habits. When it is frightened, it jumps high and far, repeating these leaps in remarkably rapid succession. It catches its insect food ("Among other insects, Chlorops, crane-flies, Thyreocoris, Calocoris rapidus, numerous pupae and wingless Aphididae and Orthoptera, have been determined from the contents of their stomachs." Bull. Ill. State Lab. Nat. Hist. H. Garman.) by giving these prodigious leaps, after the moving insect has been sighted at a distance. This power of activity, combined with its small size and protective colouration, allows it to withstand its enemies, the small snakes and lizards of the ground. The Cricket Frog stands in special need of protection. Unlike the greater number of tree frogs, it cannot climb shrubs and trees to get out of danger, because the disks of the fingers and toes are too minute. The Cricket Frog remains on the ground throughout the year, preferably along the muddy margins of pools and rivers. It is diurnal in habit. If it is disturbed when near the water, it gives one or more of its remarkable leaps, swims vigorously a few strokes,--using to good purpose the large webs between its toes,--and is immediately buried at the bottom of the pond. Very soon, however, it is in activity again, leaping from one water-lily pad to another in search of insects.

Cricket Frogs may attain a size of an inch or more, but most of those we see are very small--three-fourths of an inch long, or even less. Specimens from Texas are usually considerably larger than specimens from Florida and the Eastern States. The small size and active habits of these frogs would seem to be the reasons why they have been named the Cricket Frog. However, the name is said not to refer to these characteristics, but to their song which bears a strong resemblance to the chirping of a black cricket. These tiny frogs sing in chorus in spring, and the isolated call may be heard during the summer. The sound resembles the rattling call of the Swamp Tree Frog but the notes are more rapidly given and are sharper in quality. The sound can be imitated by striking together two pebbles or two marbles, beginning slowly and continuing more rapidly for thirty or forty strokes. The series of notes is sometimes broken into groups of three notes each. The imitation may be so good that the frogs will answer as will the Pickering's Hyla when its call is whistled. The Cricket Frogs sing constantly in captivity; they become especially enthusiastic when they are sprinkled with water. The call has not great carrying power, either when given alone or when given in chorus.