Toocog, 8.
This small tree frog was calling from herbs in a pond in the forest on June 30 and July 2. The voice is weak; probably greater numbers of males were present than are indicated by the few specimens collected, for the din from the more vociferous species made it impossible to hear Hyla picta unless one was calling close by.
Hyla staufferi Cope
Chinajá, 1.
This individual was calling from a low bush in the clearing at Chinajá. None was found in the pond in the forest at Toocog. Stuart (1935:38) and Duellman (1960:63) noted that Hyla staufferi breeds early in the rainy season. Nevertheless, I think early breeding habits do not account for the near absence of this species in our collections from southern El Petén. In early July, 1960, a few individuals were heard at a pond on the savanna at La Libertad. In mid-July of the same year they were calling sporadically from temporary ponds in the lower Motagua Valley. Possibly the individual collected at Chinajá was accidentally transported there in cargo from Toocog, from which camp at the edge of the savanna planes fly to Chinajá weekly. My observations on this species throughout its range in México and Central America indicate that it inhabits savannas and semi-arid forests and usually is absent from heavy rainforest. Stuart (1948:34) obtained this species at Cubilquitz in the lowlands of Alta Verapaz.
Phyllomedusa callidryas taylori Funkhouser
Toocog, 25.
Between June 30 and July 2 this species was abundant at a pond in the forest at Toocog. Calling males were as high as five meters in bushes and trees around the pond. At dusk males were observed descending a vine-covered tree at the edge of the pond; this strongly suggests that the frogs retreat to this tree and others like it for diurnal seclusion. Clasping pairs were found on branches and leaves above the water. The eggs are deposited in clumps usually on vertical leaves, but sometimes on horizontal leaves or on branches, vines, and aerial roots above the water. Twenty-six clutches of eggs contained from 14 to 44 (average 29) eggs. In a clutch in which the eggs are in yolk plug stage the average diameter of the embryos is 2.3 mm. and that of the vitelline membranes, 3.4 mm. Most of the eggs are in the external part of the gelatinous mass; the jelly is clear. The yolk is pale green, and the animal pole is brown. As development ensues, the yolk becomes yellow and the embryo first dark brown and then pale grayish tan. Upon hatching the tadpoles wriggle free of the jelly and drop into the water. One clutch of 19 eggs was observed to hatch in three minutes. Apparently, on dropping into the water the hatchling tadpoles go to the bottom of the pond, for one or two minutes pass from the time they enter the water until they reappear near the surface. The average total length of seven hatchling tadpoles is 7.4 mm. There is a moderate amount of yolk, but this does not form a large ventral bulge. Large tadpoles congregate in the sunny parts of the pond, where they were observed just beneath the surface. Many had their mouths at the surface. Except for constant fluttering of the tip of the tail, they lie quietly with the axis of the body at an angle of about 45 degrees with the surface of the water.
Description of tadpole (KU 60006): total length, 24.5 mm.; tail-length, 15.4 mm.; body broader than deep; head moderately flattened; snout viewed from above blunt; nostrils close to snout and directed dorsally; eyes of moderate size and directed laterally; mouth directed anteroventrally; anus median; spiracle ventral, its opening just to left of midline slightly more than one-half distance from tip of snout to vent. Tail-fin slightly more than twice as deep as tail musculature, which curves upward posteriorly; tail-fin narrowly extending to tip of tail (Fig. 4). Color in life pale gray; in preservative white with scattered melanophores; tail-fin transparent.
