Observations on the Common Toad, Rope 1899
No. 693.— March, 1899.
OBSERVATIONS ON THE COMMON TOAD
By G.T. Rope.
Hybernation.—Toads generally prefer a dry retreat in which to pass the winter. I have several times at that season found them buried in the dry soil at the top of a bank, under a thick thorn hedge. During the summer the shallow tunnels made by the Mole are often appropriated by these batrachians as diurnal retreats, and it seems not improbable that those holes which penetrate farther into the earth may sometimes be utilized as winter habitations. In like manner the burrows of our smaller rodents, those of the Bank Vole in particular, which run for a part of their course in a horizontal direction just beneath the surface-soil, are often tenanted by Toads; and one of these creatures may often be seen comfortably seated within, with its head towards the entrance.
In East Suffolk the period of hybernation appears to begin about the latter end of October, though an occasional individual may be seen moving about later. In the year 1892, near Stalham, in East Norfolk, I observed a full-grown Toad abroad on the 25th of October; and in 1888 a male was noticed hopping about here as late as the 29th of that month. As is the case with our Common Frog (Rana temporaria), the young remain active and lively up to a much later period than the adults, and hybernation with them appears to be far less complete; indeed, it is not very unusual to find them moving about well into November. In the year 1888, I saw a young Toad of the previous year climbing about among long grass and other herbage as late in the season as Dec. 3rd. Another on the same day, found secreted under a large stone, was quite brisk and lively. On Feb. 9th, 1891, a large female was turned out by the spade at a depth of about four inches, from ground which had been well dug during the previous winter, and was consequently in a comparatively loose state. This Toad sprawled feebly with all its limbs, at the same time alternatively opening and shutting its eyes. Three weeks or a month later it would probably have emerged and been making for water.
Breeding Habits.—Though the breeding season of B. vulgaris is rather later than that of R. temporaria, the former is to be seen abroad almost as early in the year as the latter. Toads have farther to travel to their breeding places than Frogs, as their winter quarters are often far removed from water. Males are often met with on their accustomed spring journey quite at the beginning of March. There is always a marked preponderance of that sex at the commencement of the breeding season, and all the time the Toads remain in the water the males exceed the females in number, though not to the same extent as at first. The former are the first to awaken from their long winter's sleep. In the year 1882, I observed a male Toad making for water as early in the year as Feb. 26th, and in the following year noticed one close to a pond in which many breed on the 28th of the same month. In 1885 one was heard "chirping" or "piping" in the same pond on March 1st. In the years 1872, '84, and '93, I saw Toads in or near water during the first week in March; while in five other years (1886, '88, '89, '90, and '94) their first appearance abroad, or rather the occasion on which their presence was first detected, has been some time during the second or third week of that month. These dates can only, of course, be considered as approximately indicating the actual first appearance.
Toads usually remain in the water till the middle of April or even later; on one occasion (in 1884) I heard one in a ditch on May 9th. After the spawning season is over they seldom resort to water, except occasionally in very hot weather, or when they are suffering from the attack of a species of fly (Musca), which deposits its eggs under the skin or within the nostrils.
The case of the Toad after these eggs are hatched is wretched in the extreme, and has been fully described by the late Mr. Newman in one of the admirable series of articles entitled "Collected Observations on British Reptiles" ('Zoologist,' Sept. 1869, p. 1830).
An irresistible impulse drives these helpless and defenceless creatures forth every spring in quest of water, but a considerable proportion never reach it, but perish by the way from some mishap or other; while others, more or less injured by wheels, hoofs, &c, manage to reach their destination in a maimed and mutilated condition, minus a few fingers or toes, or even a whole limb. The wound soon heals, and, handicapped as they are, they nevertheless make shift to move about in some fashion, both on land and in water. In March the roads near their breeding places are sometimes so crowded with Toads that it is difficult to avoid treading on them. I once counted six males within three square yards, and the next day took four from a small underground cistern not more than a foot square. At this season, before they reach the water, there seems to be a tendency among the males towards assembling in small groups of from three to five or more.
The male at this season is easily distinguished from the female by his smaller size and spare attenuated figure, which presents a strong contrast to the bulky form of his mate. His skin too becomes much smoother and more shining than at other times, somewhat resembling in texture that of the male Frog at the same season, but is not loose and baggy. The muscles of the forearm become much enlarged, and the general colouring is lighter than at other times, often taking a more decided greenish or olive tint. Possibly this may be caused by recent casting of the skin. A hard warty excrescence also is developed on the inner surface of the thumb and first finger. The skin of the female remains rough and warty as at other seasons.
Among a number of Toads spawning in a ditch, I once found a male with two of his toes entrapped and held fast by a small bivalve—some species of Sphærium or Pisidium. One of these molluscs had closed its valves upon the inner finger of one of the fore limbs, while another held tightly by the middle toe of one of the hind feet. Yet, seriously impeded as its movements must have been, the Toad was still able to swim after a sorry fashion.
At the same time and place I noticed a very small male which had only one hind leg; all the bones of the corresponding limb were apparently wanting, but the foot was present, though smaller than its fellow, and attached to the trunk by the skin alone.
Our Common Toad has a habit of swimming with the hind legs alone, keeping the fore legs or arms pressed against the sides. The Fire-bellied Frog (Bombinator igneus) often adopts the same method.
The casting of the skin frequently takes place soon after the arrival of these batrachians at their breeding places in early spring, but whether the operation is always performed at this season I do not know. In the year 1882, I noticed two females in the water casting their skin on March 20th; and in the following year met with another female thus engaged in April. I have never been so fortunate as to detect a male in the act.
The tadpoles of both Frogs and Toads are excellent scavengers, and the vast numbers which literally blacken the water of many ponds and ditches must be of great use in keeping it pure and wholesome. Decaying matter of almost any sort, animal or vegetable, is greedily devoured by them. I have seen them feeding on the dead bodies of Toads (possibly their own parents), Sticklebacks, and even of tadpoles, as well as on cow-dung which had dropped into the water; also on the soft parts of submerged and decaying leaves of trees and various plants, the veins being left untouched.
Instead of roaming about, as it were, at random in search of food, some degree of unity and method may sometimes be observed in the movements of these vast armies of tadpoles. In the marsh ditches, where they abound, it is not unusual to find two dense streams of them steadily travelling close alongside one another, but in opposite directions; an "up" and a "down" line, in fact, seems to be strictly maintained and adhered to, in order to prevent confusion. I once saw a number of tadpoles, swimming in a long continuous line, which took the form of a figure of 8. As long as I watched them they kept on steadily tracing this figure, like the dancers in a Scotch reel.
After completing their metamorphosis the young Toads, then hardly larger than the common house-fly, and nearly black in colour, soon begin to change to various shades of brown or dark grey, being always lighter on the under surface. Many acquire a more or less rufous tint, a deep dull brick-red or rust-colour being very frequent. At this stage of their existence they are decidedly pretty and even lively little creatures. Numbers of them may be seen in early summer clambering actively about the wet grass-blades and herbage growing by the pond or ditch where they were bred, but not as yet venturing far from the brink. Owing, however, to their minute size, they often escape notice.
Notwithstanding that the breeding season of the Toad is rather later than that of the Frog (according to Bell the ova are deposited about a fortnight later), the general exodus of the tadpoles of both seems to take place almost simultaneously. For this a thoroughly wet state of the ground is necessary, and, though their departure sometimes occurs much earlier, it is often delayed until the first soaking rain in August. In 1889 some young Toads in this neighbourhood (Blaxhall, Suffolk) had left water by the 27th of June, remaining, however, up to that time among the wet grass close to the ditch from whence they had emerged. On the 11th of July, however, after a heavy rain, young Toads were swarming all over the low meadows, and about the roads and lanes leading from them; but as yet none were to be seen on the higher ground. As these hordes of young batrachians spread themselves abroad over the face of the country, they show a great deal of perseverance and determination in their attempts to surmount such obstacles as bar their progress. It is amusing to watch these little fellows striving manfully to climb an almost perpendicular bank; time after time they come slipping down, but at once resume their efforts with unwearied zeal, and, being good climbers, their perseverance is often rewarded with success. On these journeys their way is beset with many dangers, and their ranks are sadly thinned by numerous enemies—such as Rats, Hedgehogs, various members of the Crow family, Fowls, Ducks, Corn-Crakes, and many other birds. In game-preserving districts, Pheasants probably clear off great numbers.
The small weak voice of the Toad is occasionally heard at other times than the breeding season, though much less frequently. I noticed it on many occasions in the year 1892, more especially from the beginning of August till October, and heard one calling in a pond in Norfolk as late as the 4th of the latter month. At almost any season, on being taken in the hand, a Toad will occasionally protest feebly against such treatment by means of its voice.
As a rule, batrachians of all kinds, as far as I am aware, breed but once in a year, having a "set time" in spring or early summer devoted to that purpose. I have nevertheless once or twice at other seasons met with Toads having the altered appearance assumed by these animals at their spawning time.
On the 14th of October, 1882, on a sandy common in Suffolk, I met with a male showing at that time those marked characteristics which I supposed to be peculiar to the season of reproduction. The skin was smooth, shining, and of a greenish tint, the forearm exceedingly thick, and the thumbs furnished with knobs; but in this case they were whitish instead of black. It called out loudly on being taken up.
- Blaxhall, Suffolk.
- The high pitched note of the Toad can hardly be called a "croak." The word "chirp" seems to express it more accurately.
- There are, however, notable exceptions to this rule regarding the regular recurrence of the breeding season; particularly in the dry climate of Australia, where the spawning time of various Frogs seems to be regulated and determined by the rainfall. Cf. J.J. Fletcher, "Observations on the Oviposition and Habits of certain Australian Batrachians" (Proc. Linn. Soc. N.S. Wales, vol. iv. (ser. 2), p. 357 (1889).