Greater short-horned lizard

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Greater short-horned lizard
Pregenant female Greater Short-Horned Lizard.jpg
Gravid female greater short-horned lizard in the Mogollon Rim region of Payson, Arizona.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Phrynosomatidae
Genus: Phrynosoma
Species:
P. hernandesi
Binomial name
Phrynosoma hernandesi
Girard, 1858
Phrynosoma hernandesi map.svg

The greater short-horned lizard (Phrynosoma hernandesi), also commonly known as the mountain short-horned lizard or Hernández's short-horned lizard, is a species of lizard in the family Phrynosomatidae. The species is endemic to western North America. Like other horned lizards, it is often called a "horned toad" or "horny toad", but it is not a toad at all. It is a reptile, not an amphibian. It is one of seven native species of lizards in Canada.

Etymology

The genus Phrynosoma, means toad-bodied. [2] The specific name, hernandesi, honors Francisco Hernández (1514–1587) a Spanish physician who wrote an early account of a horned lizard, which was published in 1615. [3] [4]

Identification

The greater short-horned lizard is often mistaken for its close relative the pygmy short-horned lizard (Phrynosoma douglasii), which has the same basic body type consisting of small pointed scales around the head and back. [3] Until recent mitochondrial DNA evidence, P. hernandesi was considered to be the same species as P. douglasii. They are now considered distinct species with the pygmy short-horned lizard (P. douglasii) occupying the northwest portion of the United States and extreme southern British Columbia. [3] When placed together the two are easily distinguished at full size, the pygmy short-horned lizard being much smaller. P. hernandesi is a highly variable species with different geographic populations exhibiting differences in color, pattern and size with some authorities describing five subspecies.

The greater short-horned lizard ranges in size from 2 to 5 inches (5.1 to 12.7 cm) in snout-to-vent length (SVL) and is a flat-bodied, squat lizard with scales around the top of the head, normally called a "crown". [5] It has a snub-nosed profile and short legs. The trunk is fringed by one row of pointed scales, while the belly scales are smooth. The color is gray, yellowish, or reddish-brown, and there are two rows of large dark spots on the back. When threatened or aggressive, its colors become more intense.

Females grow to larger sizes than males: females average about 7 cm (about 2.75 inches) SVL, with a maximum total length (including tail) of about 15 cm (about 6 inches), and weigh about 18 g (0.63 oz); whereas males have an SVL of only about 5 cm (about 2 inches), and weigh on the average about 10 g (0.35 oz). The adult male dermatocranial shape resembles that to be expected of a subadult female of the same body size. [6]

Behavior

Mountain short-horned lizard (Phrynosoma hernandesi), Culberson County, Texas, USA (19 May 2018) Mountain short-horned lizard (Phrynosoma hernandesi), Culberson County, Texas, USA (19 May 2018).jpg
Mountain short-horned lizard (Phrynosoma hernandesi), Culberson County, Texas, USA (19 May 2018)

The greater short-horned lizard is a "sit-and-wait" predator. It feeds primarily on ants, but also takes an occasional grasshopper or beetle. Often, it can be found sitting in the vicinity of a nest or trails. It is a diurnal creature, being most active during the evening and burrowing at night. It relies extensively on camouflage to avoid predators. Horned lizards have been shown to darken their skin when threatened or to regulate temperature. [7] Typically, greater short-horned lizards will remain as still as possible when a predator is nearby, attempting to blend in with the environment. [8] However if provoked, some species of horned lizards can build up blood pressure in regions behind their eyes and accurately squirt their blood at attacking predators, which will deter canids from continuing their attack. [9] It is rare for horned lizards to squirt blood at humans however, reserving this unique defense primarily for canids (i.e. foxes, coyotes, dogs), which have a strong reaction of distaste to the blood. [3] Squirting blood has been observed in the greater short-horned lizard, but has not been observed in the pygmy short-horned lizard. [10]

Reproduction

The mating season for P. hernandesi is in spring (May to June). It is viviparous, giving live birth: the female births five to 48 offspring from July to September. [5] The young measure about 24 mm (0.94 in) SVL and weigh each about 1 g (0.035 oz). The young have no horns yet and are able to take care of themselves within a few hours; they are not able to fully crawl until they are a day old. Males become sexually active after their first year of life, and females generally take two years before they can start reproducing.

Geographic range

Greater short-horned lizard, Phrynosoma hernandesi Short-horned-lizard-phrynosoma-douglassi.jpg
Greater short-horned lizard, Phrynosoma hernandesi

The greater short-horned lizard is the most widely distributed horned lizard in North America and occurs in the widest range of habitats: West into central Nevada, east into North and South Dakota, north to southern Saskatchewan and Alberta, [11] and then south into eastern New Mexico to central Mexico, with a few pockets in Trans-Pecos Texas. This species of lizard is mostly an arid mountain dweller living in the range of 900–11,300 feet (170–3440 m). [5] It is the only member of its genus in Wyoming, which counts Phrynosoma as its state reptile. It is also considered an endangered species in Saskatchewan and Alberta. [12] [13]

Habitat

The greater short-horned lizard occupies habitats from semiarid plains to high elevations in the mountains. This species is frequently found in a wide range of habitats like shortgrass prairies, sagebrush deserts, and juniper, pine, or fir forests. The soil in these habitats can be stony or rocky but usually has fine loose soil or sand present. [5] The greater short-horned lizard is more cold tolerant than other species and is able to reach higher elevations and a greater distribution where the temperature is much cooler.

Related Research Articles

<span class="mw-page-title-main">Horned lizard</span> Genus of reptiles

Phrynosoma, whose members are known as the horned lizards, horny toads, or horntoads, is a genus of North American lizards and the type genus of the family Phrynosomatidae. Their common names refer directly to their horns or to their flattened, rounded bodies, and blunt snouts.

<span class="mw-page-title-main">Thorny devil</span> Species of lizard

The thorny devil, also known commonly as the mountain devil, thorny lizard, thorny dragon, and moloch, is a species of lizard in the family Agamidae. The species is endemic to Australia. It is the sole species in the genus Moloch. It grows up to 21 cm (8.3 in) in total length, with females generally larger than males.

<span class="mw-page-title-main">Texas horned lizard</span> Species of lizard

The Texas horned lizard is one of about 21 North American species of spikey-bodied reptiles called horned lizards, all belonging the genus Phrynosoma. It occurs in south-central regions of the US and northeastern Mexico, as well as several isolated introduced records and populations from Southern United States. Though some populations are stable, severe population declines have occurred in many areas of Texas and Oklahoma. The Texas spiny lizard may be confused for a Texas horned lizard due to its appearance and overlapping habitat.

<span class="mw-page-title-main">Desert horned lizard</span> Species of lizard

The desert horned lizard is a species of phrynosomatid lizard native to western North America. They are often referred to as "horny toads", although they are not toads, but lizards.

<span class="mw-page-title-main">Coast horned lizard</span> Species of lizard

The coast horned lizard is a species of phrynosomatid lizard endemic to Baja California Sur in Mexico. As a defense the lizard can shoot high pressure streams of blood out of its eyes if threatened.

The rock horned lizard, also known commonly as Ditmars' horned lizard and camaleón de roca in Mexican Spanish, is a species of lizard in the family Phrynosomatidae. The species is endemic to the Mexican state of Sonora, in northern Mexico, south of the Arizona border. Bearing the shortest horns of all the horned lizards, it lives in thorn-scrub and deciduous Sinaloan woodlands. The rock horned lizard was "lost" to science for about 65 years. It has a unique habitat preference and limited distribution. It also had a very imprecise holotype locality record which made it difficult to locate. An extraordinary effort by Vincent Roth based on a cross-correlational analysis of gut contents from only three specimens led to its rediscovery.

<span class="mw-page-title-main">Flat-tail horned lizard</span> Species of lizard

The flat-tail horned lizard is a species of lizard in the family Phrynosomatidae. A species of reptile, it is endemic to the Sonoran desert of the southwestern United States and northwestern Mexico. Its multiple adaptations for camouflage help to minimize its shadow. The species is threatened, with a restricted range under pressure from human activities such as agriculture and development, and is specially protected in the United States.

<span class="mw-page-title-main">Roundtail horned lizard</span> Species of lizard

The roundtail horned lizard is one of the smaller species of horned lizard. Their specific epithet is from the Latin word modestum, meaning modest or calm. They are found in the United States, in western Texas, New Mexico eastern Arizona, southeastern Colorado and eight states in northcentral Mexico where they are referred to as "tapayaxtin".

<span class="mw-page-title-main">Mexican Plateau horned lizard</span> Species of lizard

The Mexican Plateau horned lizard is a species of horned lizard in the family Phrynosomatidae. The species, also known commonly as the Chihuahua Desert horned lizard, is endemic to Mexico. There are five recognized subspecies. The specific epithet, orbiculare, comes from the Latin adjective orbis, meaning "circular".

The northern desert horned lizard is a subspecies of the desert horned lizard, along with the southern desert horned lizard. It is often referred to as a "horny toad" due to its wide body and blunt snout, but it is not a toad.

<span class="mw-page-title-main">Autohaemorrhaging</span> Action of animals deliberately ejecting blood from their bodies

Autohaemorrhaging, or reflex bleeding, is the action of animals deliberately ejecting blood from their bodies. Autohaemorrhaging has been observed as occurring in two variations. In the first form, blood is squirted toward a predator. The blood of these animals usually contains toxic compounds, making the behaviour an effective chemical defence mechanism. In the second form, blood is not squirted, but is slowly emitted from the animal's body. This form appears to serve a deterrent effect, and is used by animals whose blood does not seem to be toxic. Most animals that autohaemorrhage are insects, but some reptiles also display this behaviour.

<span class="mw-page-title-main">Regal horned lizard</span> Species of lizard

The regal horned lizard is a horned lizard species native to Mexico and the Southwest United States.

Wyoming is home to 12 amphibian species and 22 species of reptiles.

<span class="mw-page-title-main">Pygmy short-horned lizard</span> Species of lizard

The pygmy short-horned lizard is a species of small horned lizard in the family Phrynosomatidae. The species is native to the northwestern United States and adjacent southwestern Canada. Like other horned lizards, it is often called a "horned toad" or "horny toad," but it is not a toad at all. It is a reptile, not an amphibian.

<span class="mw-page-title-main">San Diego horned lizard</span> Species of phrynosomatid lizard

The San Diego horned lizard or Blainville's horned lizard is a species of phrynosomatid lizard native to southern and central California in the United States and northern Baja California in Mexico.

Baur's short-horned lizard is a species of small horned lizard that is endemic to the United States.

The Sonoran horned lizard, also known commonly as Goode's desert horned lizard and el camaleón de Sonora in Mexican Spanish, is a species of horned lizard in the family Phrynosomatidae. The species is native to Arizona in the United States and to Sonora in Mexico.

References

  1. Hammerson GA (2007). "Phrynosoma hernandesi ". The IUCN Red List of Threatened Species doi:10.2305/IUCN.UK.2007.RLTS.T64076A12741970.en
  2. Sherbrooke, Wade C. (2003-05-08). Introduction to Horned Lizards of North America. University of California Press. ISBN   978-0-520-22825-2.
  3. 1 2 3 4 Sherbrooke, Wade C. (2003) Introduction to Horned Lizards of North America. California Natural History Guides.
  4. Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN   978-1-4214-0135-5. (Phrynosoma hernandesi, p.122).
  5. 1 2 3 4 Stebbins, Robert C. (2003) A Field Guide to Western Reptiles and Amphibians. 3rd ed. Peterson Field Guides
  6. Powell, G.L.; Russell, A.P.; Jamniczky, H.A.; Hallgrímsson, B. (June 2017). "Shape Variation in the Dermatocranium of the Greater Short-Horned Lizard Phrynosoma hernandesi (Reptilia: Squamata: Phrynosomatidae)". Evolutionary Biology. pp. 240–260. doi:10.1007/s11692-016-9403-6.
  7. Sherbrooke, Wade C. (1997-01-01). "Physiological (rapid) change of color in horned lizards". Amphibia-Reptilia. 18 (2): 155–175. doi:10.1163/156853897X00044. ISSN   1568-5381.
  8. Cooper Jr, William E.; Sherbrooke, Wade C. (October 2010). "Plesiomorphic Escape Decisions in Cryptic Horned Lizards ( Phrynosoma ) Having Highly Derived Antipredatory Defenses". Ethology. 116 (10): 920–928. doi:10.1111/j.1439-0310.2010.01805.x. ISSN   0179-1613.
  9. "Horned Toad (Short Horned Lizards)" National Geographic Society 2009
  10. Sherbrooke, Wade C.; George A. Middendorf, III (2001). "Blood-Squirting Variability in Horned Lizards (Phrynosoma)" (PDF). Copeia. 2001 (4): 1114–1122. doi:10.1643/0045-8511(2001)001[1114:bsvihl]2.0.co;2. JSTOR   1448403. S2CID   86061329.
  11. Reptiles Archived 2011-03-18 at the Wayback Machine . uregina.ca
  12. Endangered Species and Spaces Archived 2013-02-10 at the Wayback Machine . pc.gc.ca
  13. Powell, G. Lawrence; Russell, Anthony P. (1992). COSEWIC status report on the Greater Short-horned Lizard Phrynosoma hernandesi in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. ISBN   978-0-662-46037-4