The six-lined racerunner (''Aspidoscelis sexlineatus'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

native to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

and

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

Geographic range

The six-lined racerunner is found throughout much of the southeastern and south-central portion of the

, from Maryland to Florida in the east, across the

Great Plains The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, an ...

to southern

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

and northern

.Animal Diversity Web: ''Cnemidophorus sexlineatus''
/ref>
/nowiki> sexlineatus)] In a study conducted on A. sexlineata in Mexico, the majority of the individuals found were inhabiting areas near the seashore that were formed and influenced from maritime climate and hurricanes. The species' range also reaches north to Wisconsin and Minnesota. A small disjunct population is found in Tuscola County, Michigan.Michigan Natural Features Inventory: ''Aspidoscelis sexlineata''
/ref>

Description

The six-lined racerunner is typically dark green, brown, or black in color, with six yellow or green-yellow stripes that extend down the body from head to

tail The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, r ...

. The underside is usually white in color on females, and a pale blue in males. Males also sometimes have a pale green-colored throat. They are slender-bodied, with a tail nearly twice the body length.

Behavior

Like other species of whiptail lizards, the six-lined racerunner is diurnal and

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores were ...

. The principal foods of A. sexlineata are spiders (Araneae 16.8%), grasshoppers (orthoptera 16.8%), and leaf hoppers (Homoptera 14.1%). They are wary, energetic, and fast moving, with speeds of up to 18 mph (29 kmh), darting for cover if approached. Aggressive behavior is common, as the dominant will chase the subordinate and often follow up with a bite to signify dominance.

Habitat

Due to its extensive range, ''A. sexlineata'' is found in a wide variety of habitats including

grassland A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

s, open

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s, or rocky outcroppings. Populations have also been found abundantly in areas that experience frequent fires. It prefers lower elevations, with dry

loam Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–sil ...

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...

s. In the lower elevations, the six-lined racerunner can be found in human-made disturbances like under voltage towers or along highways and railroads.

Reproduction

Breeding takes place in the spring and early summer, with up to six eggs being laid in mid-summer and hatching six to eight weeks later. A second clutch of eggs may be laid several weeks after the first. Males have been seen to perform an act termed "cloacal rubbing" to show arousal during breeding. This act entails the male rubbing its cloaca and pelvic region on the ground while simultaneously moving forward. Males will also perform an act termed "female tending" where the male will repeatedly charge at a female trying to leave its burrow until the female allows for the male to approach and begin the reproductive process.

Prey

They will predate upon spiders, grasshoppers, and large insects ³.

Subspecies

There are three recognized

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of ''A. sexlineatus'': *Eastern six-lined racerunner, ''Aspidoscelis sexlineatus sexlineatus'' ( Linnaeus, 1766) *Texas yellow-headed racerunner, ''Aspidoscelis sexlineatus stephensae'' Trauth, 1992 *Prairie racerunner, ''

Aspidoscelis sexlineatus viridis ''Aspidoscelis'' is a genus of whiptail lizards in the family Teiidae. Taxonomy The nomenclature for the genus ''Aspidoscelis'' was published by T.W. Reeder et al. in 2002. Many species that were formerly included in the genus ''Cnemidophorus'' ...

'' Lowe, 1966

Conservation status

The six-lined racerunner is listed as a species of concern in the state of

Michigan Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the ...

, due to its limited population but otherwise holds no official conservation status.

References

External links

*
Animal Diversity Web: ''Cnemidophorus sexlineatus''Six-lined Racerunner
Reptiles and Amphibians of Iowa * {{Taxonbar, from=Q2716254 Aspidoscelis Fauna of Northeastern Mexico Reptiles of the United States Reptiles of Mexico Reptiles described in 1766 Taxa named by Carl Linnaeus Taxobox binomials not recognized by IUCN