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Horned lizards in Texas
are often menaced in their infancy by invasive fire ants.
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For the most part, reptiles here in Texas are not anything more
than an afterthought at best, and reviled at worst. However, there
is an endearing reptile that can make even the most staunch reptile-hater
smile, and that is the Texas Horned Lizard.
The Texas Horned Lizard (Phynosoma cornutum) is one of three species
of horny toads that live in Texas, and it has the largest
area of distribution. It can be observed statewide, save for a small
portion of the Texas and Louisiana border. It also occurs north
to central Kansas, west to southeastern Arizona, and southward into
the central plateau of Mexico.
The habitats that this lizard prefers are arid to semi-arid sandy
areas in prairies and grasslands, as well as sand dunes and areas
of open scrubland. Many can be seen basking on paved roads in the
morning and late afternoon hours.
The Texas Horned Lizard is a flattened reptile that has scaled,
horny skin. It is the largest horned lizard that inhabits this state,
with adults reaching a total length of six inches, although the
average is between four and five inches. The background coloration
is tan, brownish or even reddish, many times matching the soil color.
There are two large, dark brown blotches on the neck, followed by
four pairs of light-edged dark spots on each side of the white mid-dorsal
stripe along the spine. It also has a row of scales along the sides
of the body. There are nine horns that adorn the head with the two
center horns being significantly larger than the others. The belly
is white and is occasionally peppered with black spots.
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A desert horned lizard
is captured in Joshua Tree National Park as part of an effort
to monitor changes in plants and animals to track the effects
of climate change.
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Texas Horned Lizards, like other lizard species, are cold-blooded,
or ectothermic. This means that they do not generate heat from the
inside of their body, as mammals and birds do, but rather are dependent
on outside sources for heating and cooling. They are active throughout
the day in the spring and fall, adjusting their schedules to the
morning and afternoon hours during the heat of the summer.
This species of lizard has a very specialized diet. Its preferred
choice of food is the large harvester ants, and many times this
lizard can be seen dining in the vicinity of large, round nests
of the ants. An adult Horned Lizard can feed upon as many as 100
harvester ants in one day. Unfortunately, the imported fire ant
is not on the Horned Lizards dietary menu.
The Texas Horned Lizard is oviparous, which is a fancy way of saying
that it lays eggs. After emerging from the winter-long brumation
period (reptiles do not hibernate in the true sense of the word),
males will search out females to mate. After mating, the female
will lay anywhere from 10 to 30 eggs in moisture-retaining soil.
After approximately 50 days of incubation, the tiny one-inch long
young emerge prepared to fend for and care for themselves.
Populations of the misnamed horny toad (they are not
amphibians, but rather reptiles) had been decimated over the past
several decades, although in many areas they are apparently stabilizing.
There have been numerous theories presented as to the reasons for
the decline, ranging from mans use of pesticide to collection
for the pet trade. However, many studies have shown that the appearance
of the imported fire ant has had the most influence. Fire ants can
kill horny toad hatchlings, and they'll attack other ants as well,
diminishing the horny toads' food source. The Texas Horned Lizard
is the official state reptile of Texas. It is listed as Threatened
by the Texas Parks and Wildlife Department, and it may not be collected
or harassed in any way.
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National Park Service/Robb
Hannawacker
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Michael Price is owner of Wild About Texas, an educational company
that specializes in venomous animal safety training, environmental
consultations and ecotourism. Contact him at wildabouttexas@gmail.com.
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