Fowler's Toad — Part 3

Bufo fowleri Putnam

The small black-throated males sit for hours in the shallow water of the pond margin or of the marshy edge of some brook, and send forth woeful answering calls, inflating their throat-pouches enormously at each emission of sound. We can discover them by means of these inflated throats if we approach their haunt with a lantern or on a moonlight night. The swollen throats look like great light-coloured transparent spheres--like large white bubbles--among the dark grass or above the black water. That these spheres are transparent, thin-walled, and empty, except for air, is interestingly proved by looking at them from the side opposite the lantern.

A few of these toads may be heard calling from park lagoons, river margins, and ponds at any time during the late spring and the summer months. Occasionally, however, in some shallow country pond, there will be, for a few nights, so many hundreds of these toads that it would seem that all the Fowler's toads had assembled for miles around. The males outnumber the females to an astonishing extent. Out of eighty toads captured on such an occasion, only seven were females. The loud, weird chorus made by such an assembly of Fowler's Toads is described as a "terrible squawking" by some who have heard it. Others have compared it to the persistent whooping of a party of Indians.

The eggs are laid in long tangled strings, like those of the American toad. The eggs are slightly smaller than those of Bufo americanus, and may be arranged in one or in two rows in the same laying. The development of this species is rapid. Owing to the length of the breeding season, we may find young Fowler's toads of many different sizes during the summer and autumn. They show the cranial crests and the characteristic spots within three or four weeks after the tail is lost.

The adult Bufo fowleri is delicately moulded and is more slender than most North American toads. It is also better developed for leaping, the legs being unusually long.

The habit of the toad is what would be expected from its structure--it is as agile as a frog, and difficult to catch. After the breeding season, the remainder of the summer and the autumn are spent in a toad's ordinary haunts. We may see the Fowler's spotted back at the sides of country roads, in parks and gardens, and in waste fields and pastures, where insects are numerous. There is marked uniformity in size and colour among the adult toads, much more so than in Bufo americanus.

Few people, if any, living in Massachusetts and Rhode Island, realise that there are two kinds of toads in these states. Bufo fowleri differs from Bufo americanus distinctly and fundamentally as follows:

It is always yellowish or greenish grey, never taking on the rich yellow, orange, and red browns of the American toad. It is uniformly more spotted and striped in colouration. The underparts are never spotted as they are in the other toad. It is usually less fat and squat, and is much more agile. The muzzle projects farther beyond the jaw. The parotoids are narrower and are never kidney-shaped. The skin is somewhat less rough, and never has the large warts so conspicuous in the Bufo americanus. The head is less broad, the whole form more delicately moulded. The foot is less broad and thick; the toes more slender. The voices are wholly different, and could never be confused after being heard with even small attention. The time of breeding is different, Bufo fowleri not being able to endure as low a temperature as does Bufo americanus. Two to four weeks after Bufo americanus has appeared in the ponds, and, in fact, after the greater number of this species has returned to land life, Bufo fowleri comes from hibernation. Moreover, the eggs of the latter toad are often arranged in double rows. They never are, as far as reported, in the case of Bufo americanus. There should be no trouble in distinguishing the two toads. The confusion arises in regard to the cranial crests. Those of Bufo americanus are usually like the type for that species but Bufo fowleri varies most remarkably in this structure. The head crests may be parallel or may diverge; may lie close together or far apart; may be considerably elevated and sharp-edged, or low rounded ridges; may be on a raised occiput or not; and may be fused at their posterior ends, or separated by a groove as in Bufo americanus. The great variation in the cranial crests of Bufo fowleri, Bufo l. woodhousei, Bufo quercicus, and other toads would seem to indicate that this structure cannot perhaps be made so fundamental in classification as has been thought.