The Horned Toads form an interesting group of Lizards which are related
to the iguanas of the tropical forests of America. They are, however,
terrestrial lizards, inhabiting the plains of Southwestern United States
and Mexico. Their short, broad and more or less flattened bodies,
rounded heads and short tails give these animals quite a striking
resemblance to the common toad. Hence their common name. In one respect,
however, they are not at all like the toad. The head is armed behind
with a row of quite formidable horny spines, and in some of the species
shorter ones are also present on the top of the head and on various
parts of the body. As these lizards are slow in motion, the horns
constitute one of their chief means of defense. When in the presence of
an enemy “the muzzle is depressed and the horns are elevated. The back
is also arched.” The utility of the horns as a means of defense has been
amply proven. The dead bodies of snakes have been found with the horns
protruding through the skin of the body near the head. But this is not
their only means of defense. From birds they are protected by their
coloration, which is a somber mixture of brown, black and yellowish, and
when quietly resting on sands or rocks in the open they quite closely
resemble stones covered with lichens of varying shades of color.
Abundant as they are in some arid regions of the Southwest, they
frequently escape the notice of the observer because of their
coloration. In such regions, too, they can take refuge beneath the
protecting spines of the Agaves and the branches of the prickly
Opuntias. Dr. Leonhard Stejneger considers the Horned Toads a most
striking illustration of protective mimicry. Of one species he says: “In
the cedar and pine belts of the San Francisco Mountains the dark color
of the soil and stones covering the surface is closely matched by the
ground color of the Horned Toad, while the greenish gray and
orange-colored markings which somewhat irregularly adorn their backs are
perfect imitations of the lichens covering the rocks and pebbles among
which these odd looking creatures live. Near the rim of the Grand Canyon
of the Colorado, on the other hand, the ground is covered with small
pebbles of variously colored sandstone, ranging from a clayey white to
brick red and dark brown, and the specimen which I collected there is
such a faithful reproduction of the surroundings that it would
undoubtedly have remained undetected had it not been moving. Even more
remarkable are the specimens which Dr. Merriam collected in the black
lava belt. One of these was brought to camp alive.” Dr. Stejneger made a
careful study of this specimen and found that it had very closely
imitated the color of the lava, including even its glossy appearance.
One of the most remarkable habits of at least one of the species, and
possibly of all the Horned Toads, is the power of ejecting jets of blood
from the eyes. This power is rarely exercised and seemingly only when
greatly irritated. Professor L. M. Underwood relates the following
instance, which also illustrates some of the other habits of the Horned
Toads when angered: “In 1885 a student of mine received a specimen of
Horned Toad from California. In examining the animal I took occasion to
turn him on his back, using a lead pencil for the purpose. The animal
resented this treatment and showed considerable anger, opening his mouth
and puffing up his body. Irritating the animal still more, he grew more
and more enraged, until finally blood spurted from just above his eye,
which was fired at least a foot from the animal, as several spots struck
my arm considerably above my wrist. After spurting the blood the toad
became limp and collapsed, and remained in a stupor for some time, and,
when handled, behaved as if dead. After a time, possibly not over five
or six minutes, certainly not over ten, the animal revived and commenced
to run about the table.” Irritating him again in the same manner,
Professor Underwood caused the toad to go through the operation a second
time, which was followed, as in the first instance, by collapse and
stupor. “No amount of irritation could produce a third discharge,
although the animal showed some anger.”
This habit of the Horned Toads has been observed by a number of
scientists and it is said that the Mexicans have called them Sacred
Toads, “because they wept tears of blood.” An examination with a
microscope clearly shows that the ejected liquid is blood. As to the
purpose of this habit, Dr. O. P. Hay says: “It appears to me quite
likely that it is done in order to defend itself from the attacks of its
enemies, although it would not seem likely that blood would hurt the
eyes much. Nevertheless a discharge of blood into the eyes of some
persevering bird or snake might so seriously interfere with its
clearness of vision that the lizard might make its escape while the
enemy was wiping its eyes.” One investigator, at least, has had the
experience of having the stream of blood enter his eye. It was followed
by pain which lasted for some time, but was relieved as soon as the
blood was entirely wiped from the eye. Some inflammation followed, but
soon it disappeared.
Unlike some of the other lizards, the Horned Toads are not provided with
a protrusive tongue. This fact, together with their clumsy form,
prevents them from preying on the more lively insects. They chiefly feed
upon the beetles and other slowly moving insects that inhabit the region
in which they live. The food is captured in the evening, and if
undisturbed the toads remain quite passive throughout the day. In
captivity they are interesting pets and if they will take food they bear
confinement for a long time. “They not infrequently, however, starve
themselves to death, though their capacity to live without food is
marvelous.”