Coachwhip snakes (Masticophis flagellum) are found in the southern portion of Nearctic Region, limited to the United States and Mexico. In the United States, their range extends as far west as the San Francisco Bay and as far east as the Coastal Plain of North Carolina. These snakes are found as far north as Kansas and Kentucky. They are absent in areas on both sides of the Mississippi River. A few specimens have been collected in Louisiana. The species' geographic range extends as far south as the region of Durango, Mexico.
Recognized subspecies of coachwhip snakes have distinct ranges. Eastern coachwhip snakes (Masticophis flagellum flagellum) range as far west as Oklahoma and as far east as the East Coast. This subspecies ranges as far north as Missouri and as far south as Florida. The range of Sonoran coachwhips (Masticophis flagellum cingulum) encompasses almost all of Sonoran, Mexico, and their range extends as far north as Arizona. Sonoran coachwhip snakes are not commonly found in the Gran Desierto de Altar, a dune region in Sonora, Mexico. Baja California coachwhip snakes (Masticophis flagellum fuliginous) are found in the peninsula of Baja California. Red coachwhip snakes (Masticophis flagellum piceus) range as far west as southern California and as far east as Arizona. The western coachwhip snakes (Masticophis flagellum testaceus) have a range that extends as far north as Nebraska and as far south as Mexico City, Mexico. This subspecies range as far west as New Mexico and as far east as Oklahoma. (Collins and Hirschfeld, 1971; Hammerson, et al., 2007; Wilson, 1968; Wilson, 1973)
Coachwhip snakes inhabit sites that are dry, open terrain. The species can be found in deserts, prairies, scrublands, juniper-grasslands, woodlands, thorn-forests, farmlands, creek valleys, chaparral, and, occasionally, swamplands. Coachwhip snakes inhabit agricultural areas, using the vegetation as coverage. The terrestrial species can maneuver around these different habitats, finding cover in foliage and under rocks. The elevation of coachwhip snakes' habitat range from the lower elevations of Louisiana, 30 m, to the higher elevations of California, 880 m. As the habitat location varies, the elevation does as well. (Hammerson, et al., 2007; Wilson, 1968; Wilson, 1973)
Coachwhip snakes are one of the most varied snake species in North America. They are distinctly classified by their smooth scales. There are variations on the physical presentation of the species that correlate with the geographic placement of the population. Generally, the species' populations located on the eastern side of the Mississippi River vary from those on the western side. Though there are variations between and within subspecies, their colorations lend towards camouflage. Coachwhip snakes generally presents as dark brown on the anterior, dorsum portion of their body, while the midline, venter is red or pink. Coachwhip snakes are one of the largest snakes in North America, with adults ranging from 91.4 to 259 cm measured snout to vent.
Subspecies of coachwhips vary is physical presentation. Eastern coachwhips have a very dark anterior dorsum that is lighter in southern geographic locations and darker in northern locations. Sonoran coachwhips present with black bands broken up by small red bands. This trend is seen mostly in the northern geographic range, as this subspecies has been found to solid-colored in the southernmost portions of its geographic range. Western coachwhips have a pink phase on the ventral location with three distinct color patterns being supported there. The idea of polymorphism supports that coachwhips have a light and dark phase where red coachwhips and Baja California coachwhips colors range from yellows, reds, and light greys, to blacks and dark greys.
Juvenile coachwhip snakes have a different color pattern than adult coachwhip snakes. Adults can present with several color patterns depending on region and subspecies while juveniles are commonly a solid tan or brown with white spots on their snouts. (Hammerson, 1978; Wilson, 1968; Wilson, 1973)
Female coachwhip snakes have a gestation period of approximately 77.5 days. When coachwhip snakes hatch they are 27.9 to 35.6 cm long. There is limited research into juvenile development of coachwhip snakes. Juvenile coachwhip snakes have a different color pattern than adult coachwhip snakes. Adults can present with several color patterns depending on region and subspecies while juveniles are commonly a solid tan or brown with white spots on their snouts. Like most snakes, coachwhip snakes exhibit indeterminate growth, meaning they continuously increase in size until they die. Adult coachwhip snakes are between 106.7 and 152.4 cm long, measured snout to vent. (Clark, 2010; Peters and Wallach, 2005; Wilson, 1968)
Male coachwhip snakes seek out a breeding partner and initiate courting behaviors that instigate copulation. Males will display aggressive behaviors, such as flicking of the tongue, to assert dominance and ensure copulation with females. Courting behavior preceding copulation has been recorded to last 4 to 90 minutes while copulation lasts 15 minutes to 130 minutes. Females are polyandrous, breeding with several males during the breeding interval. Males have been observed defending a female they have mated with from other males, attempting to prevent further copulations. To have the greatest chance of copulation, male coachwhip snakes may defend a location from other male coachwhip snakes during the breeding season. This territorial behavior is not present outside of the breeding season. Once copulation and gestation periods have completed, female coachwhip snakes commonly lay their eggs in a nest located inside of a small animal burrow. (Hammerson, 1978; Wilson, 1968)
Coachwhip snakes are oviparous and iteroparous. They breed once a year between June and August. Males reach maturity at age 1, but it's unlikely he'd be successful in mating until age 3. Females also reach reproductive maturity at age 3. The female gestational period is an average of 77.5 days. Coachwhip snakes lay between 4-24 eggs, with an average of 11 eggs each clutch. The eggs are oblong and white with a granular surface, approximately 35-48 mm in length and 17.8-26.3 mm in width. Coachwhip snakes are not dependent upon a parent after they hatch.
Coachwhip snakes reproduce sexually with the males playing an active role in the process. Female snakes have been shown to display a significantly less active lifestyle than their male counterparts in the height of breeding season, with males being more active throughout the day than females. This difference in activity level dissipates as the breeding season ends, while males and females are equally as active. (Bennion and Parker, 1976; Goldberg, 2002; Wilson, 1968)
Snakes hatch independent from caregivers. The female coachwhip snakes lay eggs in the protection of small animal burrows in the ground. There, the eggs remain until they hatch. (Clark, 2010; Wilson, 1968)
The lifespan of coachwhip snakes is approximately 13 years in the wild. The longest living coachwhip snake held in captivity, survived for 20 years. The most common cause of death for coachwhip snakes in the wild is motor vehicle collisions. There are no apparent causes of death discussed for coachwhips held in captivity. (Clark, 2010)
Coachwhip snakes are a motile, diurnal, and solitary species. They are most active in midmorning, 0800 to 1130, and late afternoon, 1300 to 1630. In a field study by Johnson et al. (2007) in eastern Texas, coachwhip snakes were seen active from 0700 until 1700. Coachwhip snakes are most active during those times, but they can travel outside of those times. Unlike most snakes, coachwhip snakes remain active during the hottest time of day at ambient temperatures of approximately 33 ℃. Their body temperatures reach 36 ℃ at this time. Coachwhip snakes hibernate in the winter months to conserve energy. In hibernations, they lower their internal temperature to about 17 ℃. Some coachwhip snakes have been found hibernating outside of their core area, which ranges approximately 8.9 ha. Coachwhip snakes have the ability to climb trees and bushes to avoid predators. They also can go into burrows to hide away from predators. Coachwhip are capable of swimming but do not swim frequently. (Johnson, et al., 2007; Wilson, 1968)
Although coachwhip snakes have home ranges that are on average 56.2 ha, their actual activities are confined in smaller portions of this range. They move long distances among microhabitats, and these areas of use are approximately 8.9 ha. Coachwhip snakes do not commonly travel a direct path to a location, but rather through vegetation and other coverage which extends their travelling distance. During breeding season, male coachwhip snakes defend a location. The territory is a small area that has potential female mates located within, but exact territory size has not been reported. This territorial behavior is not present outside of the breeding season. (Johnson, et al., 2007)
Coachwhip snakes rely on visual, motor, and olfactory stimulations to communicate with and perceive the outside world. Their sensitive sense of smell allows them to perceive and process the world around them through chemical signals. They are an active, diurnal species, and as such, rely on visual inputs to interpret the world around them. All snakes have vomeronasal organs that allow them to capture odor particles from the air by using their tongue. The odor particles are then perceived by the vomeronasal organs. This organ, commonly called the Jacobson’s organ, is a bundle of sensory cells that allow interpretation of the environment.
Coachwhip snakes communicate with predators through visual, physical, and auditory cues. When threatened, they can coil up and vibrate in an attempt to scare off a predator. If that is not effective, they can climb trees and other foliage to evade a predator. Their speed allows them to evade a predator by fleeing.
While visual cues are important, there is no evidence to support that coloration is a predominant factor in selection of a mate by coachwhip snakes. (Cooper, et al., 1990; Wilson, 1968; Zug, 2018)
Coachwhip snakes are a nonvenomous species. Their diet consists primarily of lizards, other snakes, insects, birds and their eggs, and infrequently various amphibians. Researchers have documented instances where coachwhips have consumed rodents as well as carrion, but it is done rarely. Coachwhip snakes are a foraging species and actively search for their prey. Right after hibernation, coachwhip snakes are active primarily in midday. As their active season progresses, they increase their time spent moving, preferring the midmornings and late afternoons for foraging. Coachwhip snakes move an estimated 186 m/day. They move from spots of vegetation to burrows, foraging for their prey.
Coachwhips rely on visual and olfactory senses to capture their prey. They can perceive chemicals emitted from the integumentary system of their prey, with such precision as to be able to distinguish species they prey upon from those that are not prey. Coachwhips flick their tongues and present attack behaviors when they process chemicals from their preferred prey. Their most common prey, lizard and snake, elicit the strongest response. Once the prey has been located, coachwhips rely on their speed to capture the animal. As the fastest snake on the North American continent, with a maximum speed of 5.8 kph, capturing prey is made less complicated. (Cooper, et al., 1990; Hammerson, et al., 2007; Jones and Whitford, 1989; Secor and Nagy, 1994; Wilson, 1968)
As one of the fastest snakes in North America, with a maximum speed of 5.8 kph and the ability to turn quickly, coachwhip snakes have few natural predators. There have been recorded instances where coyotes (Canis latrans) and great horned owls (Bubo virginianus) have preyed upon the species. Speed is the most effective anti-predator adaptation that coachwhip snakes have. Speed paired with the ability to camouflage in vegetation greatly reduces the risk and frequency of predation. When threatened, coachwhip snakes coil and strike at a predator, vibrating their tail if distressed. If being pursued, it is common for coachwhip snakes to enter into rodent burrows to evade their pursuer. Upon entrance, they immediately turn their head to protect their hindquarters by biting any pursuant that attempts to grab them. When a coachwhip snake bites, they thrash their head from side to side, tearing the skin after puncturing it. (Ruben, 1977; Wilson, 1968)
Coachwhip snakes have a limited role in their ecosystem. Other than a predatory position, coachwhip snakes do not need to depend or provide for other species in a way that would evoke codependence. Parasites are present in approximately 15% of all coachwhip snakes.
The first documented parasites found in coachwhip snakes were nematodes, Physaloptera abjecta, discovered in 1856. The genus Physaloptera is the most common taxon of parasites of coachwhip snakes, often found in the stomach. The nematodes Physaloptera variegata and Kalicephalus agkistrondontis flagellum are also found in coachwhip snakes. Two apicomplexan protoans, Eimeria zamenis and Caryospora masticophis, have also been found.
Metacestodes, the larval form of tapeworms of the class Cestoda, are another common type of parasite. Acephalic, meaning no head, metacestodes, have been found in coachwhip snakes. This is notable as this kind of metacestode has never been documented in a non-mammalian host before 1990. Researchers have found other types of metacestodes in the pericardium of the snakes, interfering with heart activity.
Additional parasites are chiggers, from the family Trombiculidae. Trombicula alfreddugesi, Trombicula gurveyi campestris, and Trombicula montanensis are more common examples of the types of chiggers found. A mite from the genus Liponyssus also is an ectoparasite. (Conn and McAllister, 1990; Upton, et al., 1994; Wilson, 1968)
Coachwhip snakes prey upon potential pest animals, such as lizards, other snakes, insects, and rodents. In densely human populated areas, having a reduced number of potential pests is a benefit of having coachwhip snakes present. (Cooper, et al., 1990; Wilson, 1968)
Although coachwhip snakes are not venomous, their bite is painful. As coachwhip snakes bite, they whip the heads from side to side, causing the flesh to tear. If a human is bitten, they will likely have to seek medical care to dress the wounds properly. Humans are not commonly bit by coachwhip snakes. (Wilson, 1968)
The IUCN Red List evaluates coachwhip snakes as a species of "Least Concern." The U.S. Federal List, CITES, and the State of Michigan List all have no special status listing for coachwhips.
Habitat destruction and motor vehicle collisions, documented in areas with dense human populations, are involved in the decline of certain populations of coachwhip snakes. In a survey conducted in the Piedmont of South Carolina, the population of eastern coachwhip snakes declined from previous studies. The San Joaquin coachwhip has been listed as a “Species of Concern” by the California Department of Fish and Game. In the state of Illinois, the Prairie Research Institute lists the coachwhip as a “State Endangered” species. With a change in climate, the cost of proper conservation will increase to ensure that animals like coachwhip snakes are able to have inhabitable environments. Securing habitats that support coachwhips is one of the leading tactics to conserve coachwhip populations that are at risk. ("Coluber flagellum Shaw, 1802 -- Coachwhip", 2018; Hammerson, et al., 2007; Mitrovich, et al., 2009; Platt, et al., 1999; Shaw, et al., 2012)
Hannah Stewart (author), Radford University, Alex Atwood (editor), Radford University, Layne DiBuono (editor), Radford University, Lindsey Lee (editor), Radford University, Karen Powers (editor), Radford University, Joshua Turner (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
uses sound to communicate
living in landscapes dominated by human agriculture.
flesh of dead animals.
Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.
uses smells or other chemicals to communicate
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
Animals with indeterminate growth continue to grow throughout their lives.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
specialized for swimming
the area in which the animal is naturally found, the region in which it is endemic.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).
"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.
scrub forests develop in areas that experience dry seasons.
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
movements of a hard surface that are produced by animals as signals to others
uses sight to communicate
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