Great Plains rat snakes (Pantheris emoryi) are native to the United States and northern Mexico. They live in a wide variety of habitats that range from southwestern Illinois to southwestern Colorado and from eastern New Mexico to northern Mexico. These snakes occur throughout most of Kansas, following the Arkansas, Smoky Hill, Soloman, Saline, Cimarron, and Republican rivers. They are absent in much of the rest of the High Plains, the formerly glaciated regions north of the Kansas River and east of the Flint Hills, the Wellington Lowlands, and the lower Neosho River basin. There is an isolated population along the Bear Creek drainage in Stanton County, Kansas, which is further supported by specimens in adjacent areas of Colorado. (Ernst and Ernst, 2003; Gillingham, 1979; Sperry and Taylor, 2008)
Great Plains rat snakes occupy a wide variety of habitats including fields, hill prairies, brushy areas, woodlands, riparian areas, canyons, barn yards and abandoned houses. They avoid heavily forested regions and can be found hiding under rocks, logs, boards, in rock crevices, and in small mammal burrows. They are also semi-arboreal and may be found climbing high in trees hunting for birds. They primarily forage nocturnally and remain hidden during the day.
Although elevation has not been reported in scientific literature, an informal reptile database lists their elevational range as 0 to 1800 m. It is unlikely that they use all elevational gradients equally. Most of their geographic range is in the central United states, which falls largely in the mid-range elevations – between 300 and 600 m. (Ernst and Ernst, 2003; Graham, 2018; Klug, et al., 2011)
Great Plains rat snakes have black and white checkered bellies with stripes under their tails. Their head has a V or spear-point mark leading to the neck and large brown blotches that extend down the mid line of their backs, which are flanked by two rows of smaller blotches. The rest of their scales are grey to light-brown. Their scales are slightly keeled and their anal plate is divided.
Adults range from 61 to 153 cm in snout-vent length (SVL). Males are slightly larger and heavier than the females. Males reach maturity at around 134 cm and females reach maturity at around 125 cm.
The young resemble adults and are similar in appearance. Hatchlings have an SVL that ranges from 20 to 36 cm.
Some similar species include bull snakes (Pituophis catenifer sayi), black rat snakes (Pantherophis obsoletus), glossy snakes (Arizona elegans), and speckled kingsnakes (Lampropeltis holbrooki). Bull snakes have scales with more distinct keels. Black rat snakes lack spear-point markings on their heads. Glossy and speckled kingsnakes have smooth scales and a single anal plate. (Dowling, 1951; Ernst and Ernst, 2003; Sievert and Sievert, 1993)
After a gestation time of 5 to 7 weeks, female Great Plains rat snakes lay their eggs in June or July. The length of time the eggs incubate, typically 56 to 60 days, depends on temperature and the general condition of their habitat. If summers are cooler and ground temperatures drop below 26.67°C (80°F), eggs may take longer to incubate. Larger females lay larger eggs and have larger clutch sizes.
At hatching, eggs weigh 13.05 to 16.0 g. Hatchlings range from 25.4 to 30.38 cm SVL and their birth masses range from 9.4 to 11.3 g. Growth rate is fast in hatchlings and juveniles but slows down as they reach maturity. Growth does not stop at maturity, as these snakes grow indeterminately. Males grow faster and get larger than females. Males reach maturity at around 134 cm, at 6 to 8 years of age. Females reach maturity at around 125 cm, at 8 to 10 years of age. (Clark, 1953; Ernst and Ernst, 2003; Gillingham, 1979; Meshaka and Schmidt, 2017)
Reported mating dates for Great Plains rat snakes are between May 26th and June 9th. During breeding season males are combative towards other males. Great Plains rat snakes are polygynandrous, meaning males and females both have multiple mates. These snakes communicate with their mates using a complex rhythmic dance. This behavior usually involves touching followed by a male chasing a female. This is followed by more rhythmic dancing and forward jerking. Males usually bite females in their necks or trunks before mating is complete. Great Plains snakes are oviparous and their natural egg-laying sites include standing and fallen hollow trees, compost, mulch and sawdust piles, and decomposing logs. Some of these sites are used repeatedly. (Clark, 1953; Ernst and Ernst, 2003; Gillingham, 1979; Klug, et al., 2011; Zug, et al., 2001)
Great Plains rat snakes breed once yearly, in May or early June. After 5 to 7 weeks of gestation, female Great Plains rat snakes lay 12 to 24 eggs in June or July. These eggs incubate for 55 to 60 days; this time may vary depending on the temperature and other environmental conditions. If the summers are cooler and ground temperatures drop below 26.67°C, it can lead to longer incubation times. Larger females lay larger eggs and have larger clutch sizes.
Hatchlings range from 25.4 to 30.48 cm in length and have birth masses from 9.4 to 13.2g. The number of offspring produced successfully is 3 to 12. Hatchlings are immediately independent and will stay near their hatching site for up to two years. Females reach sexual maturity at 8 to 10 years. For males it only takes 6 to 8 years. (Clark, 1953; Dowling, 1951; Gillingham, 1979; Sperry and Taylor, 2008; Stake, 2001)
Beyond the act of mating, there is no parental investment from male Great Plains rat snakes. There is some provisioning and protecting of nesting sites by females before they lay their eggs, but young are independent upon hatching. (Dowling, 1951; Gary, 2005; Gillingham, 1979; Sperry and Taylor, 2008; Stake, 2001)
Lifespans have not yet been reported for Great Plains rat snakes. Other members of their genus such as black rat snakes (Pantherophis obsoletus) have reported longevities of up to 21 years in the wild and 23 years in captivity. Corn snakes (Pantherophis gutattaus) have life spans that average 18 years in the wild and 21 years in captivity. It is likely that Great Plains rat snakes have comparable lifespans to such species. Lifespans in the wild may be limited due to habitat loss, poor environmental quality, and lack of food. (Ernst and Ernst, 2003; Markle, et al., 2020; Prior and Patrick, 1996; Sperry and Taylor, 2008)
Great Plains rat snakes are solitary. Like most rat snakes, when agitated, Great Plains rat snakes will shake their tails vigorously. This makes no noise by itself, but when among dry leaf litter, it sounds like a rattlesnake. This often leads to misidentification. These snakes will also strike vigorously when agitated or threatened. When touched they will release a bitter smelling musk. Males become combative during mating season.
Great Plains rat snakes avoid heavily forested regions and are often found hiding under rocks, logs, boards, in rock crevices and in small mammal burrows. They are semi-arboreal and can be found climbing high in trees hunting for birds. They are also capable of swimming. Because of their reclusive nature, Great Plains rat snakes primarily forage nocturnally, staying hidden during the day. Great Plains rat snakes hibernate every year, and do so alone. Hibernation can be affected by water level fluctuations leading to freezing, dehydration, and flooding. Flooding is the largest cause of mortality for Great Plains rat snakes. For the majority of their range, they hibernate from late November into late February and early March. For the northernmost regions of their range, hibernation may extend until May or June. Hibernation is triggered not just by temperature, but also by lack of food and shorter days. They hibernate on rocky, south-facing slopes, typically with some trees on which to bask.
Prior and Weatherhead (1996) found that each rat snake in their study selected 0 to 11 trees for basking, and that their most commonly used trees were older oaks (Quercus). These oak trees provide trunks and numerous cavities for cover. (Clark, 1953; Ernst and Ernst, 2003; Gillingham, 1979; Markle, et al., 2020; Meshaka and Schmidt, 2017; Mullin and Cooper, 1998; Prior and Patrick, 1996; Stake, 2001)
Home ranges for male Great Plains rat snakes are an average 0.13 km^2, while females average 0.15 km^2. These snakes maintain the same home range for many years, sometimes their entire life. Males typically utilize more of their home ranges than females. Males become more active during spring when they are searching for mates. Females do not travel their home range as much, remaining in one place more often than males do. (Ernst and Ernst, 2003; Gillingham, 1979; Klug, et al., 2011)
Great Plains rat snakes are solitary snakes that communicate little with others. Social communication is limited to mating season, when males become combative towards each other. Great Plains rat snakes communicate with their mates with a complex rhythmic dance. This behavior usually involves physical contact followed by males chasing females. Males then mount and display dorsal advance movements. Rhythmic dancing and forward jerking occurs as they mate. After mating, males usually bite females in their necks or trunk regions.
These snakes have a highly developed sense of smell. Their forked tongues collect scents and compounds from whatever it touches and from the air around it. When the tongue goes back into the mouth, these forks touch a special sensory organ called the Jacobson's organ on the roof of the mouth; this helps snakes sense smells around them. Just like in all snakes, Great Plains rat snakes detect thermal images through infrared and sense vibrations through their jaws when hunting prey. They also release and sense pheromones when mating. (Ernst and Ernst, 2003; Gillingham, 1979; Sievert and Sievert, 1993)
Rodents are the main prey item of Great Plains rat snakes. They will also eat grassland birds (including eggs), and occasionally other snakes, lizards, and frogs. They subdue all prey items via constriction. They also frequent caves, where they eat bats. There are no studies quantifying diet components by percentage. It is unknown if juvenile diets differ from adults. (Dowling, 1951; Ernst and Ernst, 2003; Gillingham, 1979; Klug, et al., 2011; Sievert and Sievert, 1993)
Great Plains rat snakes are most vulnerable to predators when they are hatchlings and juveniles. Some of their known predators include gray foxes (Urocyon cinereoargenteus), red foxes (Vulpes vulpes), owls, raccoons (Procyon lotor), and red-tailed hawks (Buteo jamaicensis). Adults have few known predators other than humans (Homo sapiens). They are often killed because they are misidentified as rattlesnakes. If harassed, these snakes will shake their tail vigorously in dry leaf litter, sounding remarkably like a rattlesnake. They also strike vigorously when agitated or threatened. (Dowling, 1951; Ernst and Ernst, 2003; Gillingham, 1979; Klug, et al., 2011; Sievert and Sievert, 1993; Stake, 2001; Zug, et al., 2001)
Great Plains rat snakes contribute to their ecosystem by assisting in rodent population management in rural and urban areas. In rural areas they feed mainly on rodents that destroy farmers grain stores. Although Great Plains rat snakes are known to be arboreal and prey on nesting birds, they mainly feed on rodents if local populations are large and summers are warm. This indirectly leads to greater nesting success for birds in the region. Great Plains rat snakes are a food source for foxes, owls, raccoons (Procyon lotor), and red-tailed hawks (Buteo jamaicensis).
Great Plains rat snakes are hosts to parasites such as snake mites (Entophionyssus glasmacheri) and tiny parasitic protozoans that live inside snakes such as coccidians (Eimeria zamenis) and apicomplexans (Caryospora duszynskii). (Clotfelter, et al., 2007; Emerson, 2015; Fajfer, 2012; Ferraro, et al., 2008; McAllister, et al., 2011; Wolfe, et al., 2018)
Great Plains rat snakes have economic importance to farmers in rural areas because they feed mainly on rodents that destroy farmers grain stores. Great Plains rat snakes are known to prey on nesting birds, but will mainly feed on rodents if the populations are healthy. This leads to more success in nesting birds, which benefits the thriving birdwatching community. Great Plains rat snakes are legally sold in the pet trade and are available in different color morphs. Normal morph Great Plains rat snakes are sold for around 40 US dollars as hatchlings and albino morph hatchlings can be purchased for around 200 US dollars. The state of Texas allows them to be legally collected with the purchase of a hunting license. (Clotfelter, et al., 2007; Emerson, 2015; Ernst and Ernst, 2003; Ferraro, et al., 2008; LaDuc and Cannatella, 2010; Reptmart, 2020; Underground Reptiles, 2020; Wolfe, et al., 2018)
Great Plains rat snakes are non-venomous but they will bite if agitated. There are no other adverse economic effects of Great Plains rat snakes on humans. (Clotfelter, et al., 2007; Emerson, 2015; Ernst and Ernst, 2003; Ferraro, et al., 2008; Wolfe, et al., 2018)
Great Plains rat snakes are "Least Concern" on the IUCN Red List and listed as "no special status" on CITES, the US Federal List and in the State of Michigan's Rare Animal List. NatureServe lists them as "Critically Imperiled" in Illinois (State Threatened), and "Vulnerable" in Arkansas, Utah, and Colorado. Threats such as highway traffic and habitat loss due to human destruction and expansion have negatively impacted some populations of Great Plains rat snakes. Some populations have fewer numbers while others have been eliminated. Hammerson (2020) reports populations of Great Plains rat snakes are relatively stable but declining in some areas at an average rate of less than 10% over a 10 year period of time. Conservation efforts include minimizing habitat loss and monitoring legal hunting and collecting through hunting licenses. (Hammerson, 2020; Illinois Natural History Survey, 2020; LaDuc and Cannatella, 2010)
brandon Crawford (author), Radford University, Lauren Burroughs (editor), Radford University, Logan Platt (editor), Radford University, Karen Powers (editor), Radford University, Galen Burrell (editor), Special Projects.
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.
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
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.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
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.
(as keyword in perception channel section) This animal has a special ability to detect heat from other organisms in its environment.
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).
marshes are wetland areas often dominated by grasses and reeds.
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
specialized for swimming
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the business of buying and selling animals for people to keep in their homes as pets.
chemicals released into air or water that are detected by and responded to by other animals of the same species
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
living in residential areas on the outskirts of large cities or towns.
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
uses touch to communicate
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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