Everything about Horned Lizard totally explained
Horned lizards (
Phrynosoma) are a genus of the
Phrynosomatidae family of
lizards. The horned lizard is popularly called a "horned toad," "horny toad", or "horned frog," but it's neither a
toad nor a
frog. The popular names come from the lizard's rounded body and blunt snout, which make it resemble a toad or frog. (
Phrynosoma literally means "toad-bodied.") The spines on its back and sides are made from modified scales, whereas the horns on the heads are true horns (for example they've a bony core). There are 14 species of horned lizards in
North America, 8 of which are native to the
United States. The largest-bodied and most widely distributed of the U.S. species is the
Texas horned lizard (
P. cornutum).
Description
Horned lizards are morphologically similar to the
Australian
thorny devil (
Moloch horridus), but are only distantly related. They also have other unique similarities, such as being sit-and-wait predators and preying upon
ants, and so the two species are considered a great example of
convergent evolution.
Protection against predation
Horned lizards use a wide variety of means to avoid
predation. Their coloration generally serves as
camouflage. When threatened, their first defense is to remain still and hope to avoid detection. If approached too closely, they generally run in short bursts and stop abruptly to confuse the predator's visual acuity. If this fails, they puff up their body to cause its spiny scales to protrude, making it appear larger and more difficult to swallow. At least four species are also able to squirt an aimed stream of
blood from the corners of the eyes for a distance of up to 3 feet. They do this by restricting the blood flow leaving the head, thereby increasing blood pressure and rupturing tiny vessels around the
eyelids. This not only confuses predators, but also the blood tastes foul to
canine and
feline predators. It appears to have no effect against predatory
birds. To avoid being picked up by the head or neck, horned lizards duck or elevate their head and orient their cranial horns straight up, or back. If a predator tries to take it by the body, the lizard drives that side of its body down into the ground so that the predator can't easily get its lower jaw underneath the lizard.
Diet and decline
The diet of most horned lizards species varies from 60-90%
harvester ant of the genus
Pogonomyrmex, though they're opportunistic and supplement these with
termites,
beetles,
grasshoppers and other small
insects.
In
California,
Texas, and other states, horned lizards are considered threatened and given state protection, though none are on the federal endangered species list. The
Texas horned lizard has declined in about 30% of its range, though there's some indication it may be making a comeback. Some California species are also in decline. The decline is usually blamed on development/destruction of habitat, the spread of non-native
South American ants which compete and war with the harvester ant, and the overuse of
pesticides which kill harvester ants. In California, the introduced species is the
Argentine ant. In Texas, it's the Argentine ant and the
Brazilian
fire ant. Both species are highly aggressive and fiercely territorial, and prey on harvester ant queens, destroying the horned lizard's principal source of food.
In culture
Some
Native American peoples regarded horned lizards as sacred. The animal is a common motif in the art of many
Native Americans in the Southwestern U.S. and in
Mexico. In the
Clint Eastwood film
The Outlaw Josey Wales, the character played by
Chief Dan George decides to go to
Mexico based on signs given him by a horned toad.
The horned lizard is the state
reptile of both
Texas and
Wyoming, and as the "horned frog," is the mascot of
Texas Christian University (TCU).
Species
- Giant Horned Lizard, Phrynosoma asio (Cope, 1864)
- Short-tailed Horned Lizard, Phrynosoma braconnieri (Duméril, 1870)
- Cedros Island Horned Lizard, Phrynosoma cerroense (Stejneger, 1893)
- Texas Horned Lizard, Phrynosoma cornutum (Harlan, 1825)
- Coast Horned Lizard, Phrynosoma coronatum » * Cape Horned Lizard, Phrynosoma coronatum coronatum (Blainville, 1835)
* San Diego Horned Lizard, Phrynosoma coronatum blainvillii (Gray, 1839) » * California Horned Lizard, Phrynosoma coronatum frontale (Van Denburgh, 1894)
* Central Peninsular Horned Lizard, Phrynosoma coronatum jamesi (Schmidt, 1922) » * Northern Peninsular Horned Lizard, Phrynosoma coronatum schmidti (Barbour, 1921)
- Rock Horned Lizard, Phrynosoma ditmarsi (Stejneger, 1906)
- Short-horned Lizard, Phrynosoma douglassii » * Phrynosoma douglassi brachycercum (Smith, 1942)
* Phrynosoma douglasii douglasii (Bell, 1828)
- Mountain Short-horned Lizard, Phrynosoma hernandesi (Girard, 1858)
- Flat-tail Horned Lizard, Phrynosoma mcallii (Hallowell, 1852)
- Roundtail Horned Lizard, Phrynosoma modestum (Girard, 1852)
- Mexican Plateau Horned Lizard, Phrynosoma orbiculare » * Phrynosoma orbiculare boucardii (Duméril & Bocourt, 1870)
* Phrynosoma orbiculare bradti (Horowitz, 1955) » * Phrynosoma orbiculare orbiculare (Linnaeus, 1789)
* Phrynosoma orbiculare orinetale (Horowitz, 1955) » * Phrynosoma orbiculare cortezii (Duméril & Bocourt, 1870)
* Phrynosoma orbiculare dugesii (Duméril & Bocourt, 1870)
- Desert Horned Lizard, Phrynosoma platyrhinos » * Southern Desert Horned Lizard, Phrynosoma platyrhinos calidiarum (Cope, 1896)
* Northern Desert Horned Lizard, Phrynosoma platyrhinos platyrhinos (Girard, 1852) » * Sonoran Horned Lizard, Phrynosoma platyrhinos goodei (Stejneger, 1893)
- Regal Horned Lizard, Phrynosoma solare (Gray, 1845)
- Mexican Horned Lizard, Phrynosoma taurus (Dugés, 1873)
- Gulf Coast Horned Lizard, Phrynosoma wigginsi (Montanucci, 2004)
Further Information
Get more info on 'Horned Lizard'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://horned_lizard.totallyexplained.com">Horned lizard Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |