Reptile

Little Bighorn Battlefield National Monument preserves habitat utilized by 14 of the 20 reptile species found in Montana. Reptiles are a class of animal that includes snakes, lizards, turtles and tortoises, and crocodilians. Reptiles are unique from other classes because they have scaly skin, are ectothermic, and give birth to young that resemble their parents –a combination no other class in the animal kingdom possesses.

Scaly skin is a vital adaptation to reptile survival. Reptile scales function as a connected "sheet" that is shed and regrown periodically. Most reptiles shed skin in chunks, but snakes shed skin in one piece. Turtles and tortoises have scaly skin too. Their shells are complex structures made of bone and scales that develop from their skin. Reptiles rely on their characteristic scaly skin to retain water and survive in a wide range of environments.

Reptile species are able to live in all environments, except polar ice and tundra, because they are ectotherms. This means they do not use their metabolism or other physiological processes, such as sweating or shivering, to maintain a constant body temperature. Instead, ectotherms use their behavior and the environment. Reptiles are commonly seen basking in the sun to warm themselves. When it's too cold to bask, they enter a hibernation-like state underground known as brumation. When it's too hot to bask, reptile aesivate. This means they only become active at night when the risk of overheating is reduced. These responses allow reptiles to thrive despite challenging environmental conditions from birth.

Reptiles do not undergo metamorphosis at any point in their lives. At birth, young reptiles resemble their parents although coloration may vary. Most reptile species hatch from eggs laid on land;this is advantageous because reptiles use lungs to breathe. However, some reptiles are able to live in aquatic environments. For example, the painted turtle spends the winter months burrowed in the mud at the bottom of freshwater habitats. Their skin can absorb oxygen in water and can withstand much colder temperatures than most ectotherms. They are the most widely distributed turtle in North American due to these adaptations.

The 14 reptile species at Little Bighorn Battlefield National Monument are usually seen on land. Those species are listed below.

Northern Rubber Boa (Charina bottae)

Common Gartersnake (Thamnophis sirtalis)

Gophersnake (Pituophis catenifer)

North American Racer (Coluber constrictor)

Plains Gartersnake (Thamnophis radix)

Plains Hog-nosed Snake (Heterodon nasicus)

Terrestrial Gartersnake (Thamnophis elegans)

Western Milksnake (Lampropeltis gentilis)

Painted Turtle (Chrysemys picta)

Common Sagebrush Lizard (Sceloporus graciosus)

Greater Short-horned Lizard (Phrynosoma hernandesi)

Snapping Turtle (Chelydra serpentina)

Spiny Softshell (Apalone spinifera)

Prairie Rattlesnake (Crotalus viridis)

 

Common Name: Northern Rubber Boa

Scientific Name: Charina bottae

Other Names: Rubber Boa

Identification: Adults have a uniform base color that ranges from tan to olive green to brown. Their underside is light yellow, and some individuals have additional brown mottling. The young are pink and slightly transparent, but darken with age. This snake looks and feels like rubber, and has a distinctively blunt tail. It is a small, shiny snake that can vary from 12 to 28 inches (30 to 71 centimeters) long when fully grown. The scales are small and smooth on the body, but are larger on the head.

Habitat: Rubber Boas spend a lot of time underground in rodent-excavated tunnels or rock fractures. They are usually found under logs and rocks in forest habitats near water. They are often spotted thermoregulating under surface objects in the warm sun during the spring and fall months. They remain underground for most of the summer to keep cool and moist. However, they can be active during the summer. Young boas are able to float, and all rubber boas are able to keep their head above water.

Behavior: Rubber boas are slow-moving, docile snakes. They never use striking as a defense mechanism, but they will excrete a very smelly substance. They are primarily nocturnal, but are occasionally seen sunning themselves on roads, trails, or in open areas. They feed on mice, shrews, salamanders, small snakes, and lizards. They are vulnerable to most carnivorous predators due to their slow nature; their strongest defense against predation is its secretive nature. Female rubber boas give birth to two to eight live young in late summer or early fall.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=arada01010

 

Common Name: Common Gartersnake

Scientific Name: Thamnpohis sirtalis

Identification: The Common Gartersnake has two color variations in Montana. The first has three yellow longitudinal stripes, one down the backbone and one on each side. Black stripes broken by red spots are between the yellow stripes. The second color variation has the same longitudinal yellow and black striping pattern, but without red dots. The underside ranges from yellow to bluish in all of Montana's Common Gartersnakes. However, some individuals with red markings have been recorded with small black dots on the edge of their underside scales. The adult Common Gartersnake ranges from 16 to 42 inches (40 to 107 centimeters) in length. They are between 4.7 and 9 inches (12 and 23 centimeters) at birth.

Habitat: Common Gartersnakes are found in most habitats, but are frequently seen at lower elevations around water. They prefer moist habitats, and may travel up to ten and a half miles (17 kilometers) between their winter dens and their preferred summer ranges.

Behavior: Common Gartersnakes eat a variety of vertebrates and invertebrates. Mating occurs in the spring. Females give birth to 6 to 18 live young from July through September. Larger females give birth to more young. They are inactive in the winter and hibernate in cold climates, but may emerge on warmer winter days. Common Gartersnakes often release a repulsive odor if captured.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=aradb36130

 

Common Name: Gophersnake

Scientific Name: Pituophis catenifer

Other Names: Gopher Snake,Bullsnake, Pituophis catenifer sayi

Identification: The Gophersnake or Bullsnake is Montana's largest snake. They can reach a length of 7feet (2.1 m), but most individuals range from 3 to 5 feet (0.9 to 1.5 m). They have a yellow base color with a series of black or brown blotches down their back and sides. The blotches are spaced further at the tail. The snake's underside is yellow or white and frequently has black spotting. A black band is usually visible in front of and below the eyes. They are often mistaken for the prairie rattlesnake.

Habitat: Gophersnakes prefer dry habitats while having an extensive range. The species is present in western North America from southern Canada to northern Mexico. The snake is terrestrial, fossorial, and arboreal. They can be found in prairie grasslands, canyons, open pine forests, and suburban and agricultural areas. They remain underground during the hot midday period in summer, and hibernate in deep crevices or dens in large groups in winter.

Behavior: They sometimes hiss and vibrate their tail when alarmed, which looks and sounds similar to a rattlesnake. Mating occurs in the spring. Females lay 2 to 24 eggs between June and August in loose soil, small mammal burrows, or under large rocks and logs. The eggs hatch after 9 to 11 weeks of unattended incubation. Gophersnakes have been known to live up to 20 years.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=ARADB26020
 

Common Name: North American Racer

Scientific Name: Coluber constrictor

Other Names: Eastern Racer

Identification: The North American racer is a long, slender snake. Adults range from 36 to 60 inches (90 to 152 cm) long, and the longest recorded individual is 72 inches (183 cm). Adult base color varies between green, blue, and brown. The underside ranges from light yellow to white, however the chin and throat area is usually more yellow than the abdominal area. Juvenile snakes have a gray base color with reddish-brown or black blotches. Their undersides have a white base color covered in small reddish-brown spots. Adult and juveniles have relatively large eyes and smooth scales.

Habitat: The North American Racer occupies forested hillsides, bluff prairies, grasslands, and open woods. The preferred summer habitats are woodland margins and field edges. They seem to locate near covered areas in shortgrass prairie environments. In winter, they hibernate in small groups with other snake species in mammal burrows, caves, rock crevices, gravel banks, stone foundations, and wells.

Behavior: The North American Racer usually emerges from hibernation in late April although they remain close to their hibernation den for several days after emerging. Breeding occurs in May and early June. Females lay 8 to 21 eggs under rotting logs, stumps, or inside mammal burrows in late June or Early July. Eggs hatch in late August or early September after six to nine weeks of incubation. They are opportunistic feeders that prey on insects and small vertebrates such as mice and frogs. They do not kill with constriction;instead they capture prey with their mouths and subdue it.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=ARADB07010

 

Common Name: Plains Gartersnake

Scientific Name: Thamnophis radix

Other Names: Plains Garter Snake

Identification: Background color isolive, brown, or black. An orange or yellow dorsal stripe runs down the middle of the back, and there is a light stripe on each side that can be yellow, green, or blue. The area between the light stripes is an alternating row of black spots. The underside is gray or greenish gray with a row of black spots along each side. Adults range from 16 to 42 inches (40 to 107 cm). Newborns are about 6 to 7.5 inches (15 to 19 cm).

Habitat: Plains Gartersnakes are found in nearly all habitats, but most commonly in shortgrass prairie environments at lower elevations around water. They take shelter under logs, rocks, or other large objects. Hibernation sites include rodent burrows, crevices, anthills, old wells, and spaces under concrete. Some individuals hibernate underwater.

Behavior: The Plains Gartersnake is normally active from March to October although that depends on the weather. Mating occurs in the spring. Young are born between late July and early September. A litter size can range from 5 to 60, but nine is the average litter size. They eat earthworms, minnows, salamanders, tadpoles, frogs, toads, and small rodents. They will smear a musky secretion from glands at the base of their tail when captured or handled.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=ARADB36100 W
 

Common Name: Plains Hog-nosed Snake

Scientific Name: Heterodon nasicus

Other Names: Western Hog-nosed Snake

Identification: The Plains Hog-nosed Snake is a heavy-bodied snake with a broad neck. The base color can be tan, grey, olive green, or dark brown. There are a series of dark oval blotches down the center of the back with smaller blotches along the side. The underside has lots of black pigmentation along with patches of white, yellow, and orange. The snout is upturned because it is used for digging. Adults range from 15 to 25 inches (38 to 63.5 cm) long, but the longest recorded size is 39.6 inches (100.6 cm). The young are 6.5 to 7.5 inches (17 to 19 cm) when they hatch.

Habitat: They prefer prairie habitat with open, sparsely vegetated habitats on well-drained soils. In Montana, they are spotted in sage-brush grassland habitat and near pine savannahs. They usually overwinter below the frost-line in mammal tunnels or self-dug burrows, and they emerge early in the spring. Their home range is relatively small;the longest recorded movement was by a female that travelled one mile (1.6 km) over ten months.

Behavior: Breeding takes place inform mid-April through May. Females lay 2 to 24 eggs in late May or early June. The eggs hatch after seven or eight weeks. They eat toads, frogs, salamanders, lizards, small snakes, and small rodents. It subdues its prey with mildly toxic saliva. The species is generally docile and rarely bites. However, individuals will flatten their head like a cobra when approached and may hiss and strike. They play dead if confronted for too long;they roll on their backs, open their mouths, and give off a bad odor to make the deception more believable.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=aradb17010

 

Common Name:Terrestrial Gartersnake

Scientific Name:Thamnophis elegans

Identification:Terrestrial Gartersnakes have three yellow stripes running the length of their body, on down the center of the back and one on each side. A series of black spots are between and somewhat on the stripes. The background color ranges from brown to green. The underside is gray and can have dark markings concentrated on the mid-ventral line. However, this species is highly variable in pattern and coloration, and the occasional all-black individual is found. Adults range from 16 to 43 inches (40 to 110 cm) in length.

Habitat:They are found in nearly all habitats, but are frequently seen at lower elevations near water. This includes brushy prairie bottomland areas;desert riparian areas;irrigation canals;and pond, lake, and river edges. In high elevations, they are commonly spotted on rocky cliffs and brushy talus.

Behavior:Terrestrial Gartersnakes usually breed in the spring, but fall mating has been reported. They give live-birth and do not lay eggs –a characteristic shared by all gartersnakes. Usually 4 to 19 young are born between July and September. They feed on a variety of vertebrates and invertebrate;they commonly eat slugs, worms, snails, tadpoles, frogs, fish, mice, small birds and lizards, and even some of their own species. They are preyed on by birds. To help defend themselves, they secrete and smear substances from their scent glands all over themselves and their predator. Their saliva is also mildly poisonous.

More Information:http://fieldguide.mt.gov/speciesDetail.aspx?elcode=aradb36050

 

Common Name: Western Milksnake

Scientific Name: Lampropeltis gentilis

Other Names: Pale Milksnake, Central Plains Milksnake

Identification: The Western Milksnake is a tri-colored snake;the back and sides of the body are marked with whitish, black, and reddish or orange bands. The reddish-orange bands are borders by black bands. In some individuals, the bands extend across the snakes underside, but the underside is entirely white in other individuals. The snout is black, but sometimes has white flecking. Hatchlings have a similar appearance to adults and are 6 to 11.5 inches (16 to 29 cm). Adult length ranges from 15 to 33.5 inches (39 to 85 cm). Eggs are slightly granular and range from 1.14 to 1.7 inches (29 to 44 mm) in length by 0.5 to 0.6 inches (13 to 16 mm) in breadth.

Habitat: Little is known about the Western Milksnake's habitat preferences in Montana. They have been reported in areas of open sagebrush-grassland habitat and ponderosa pine savannah with sandy soil. They are most commonly seen in areas with rocky outcrops and hillsides or badland scarps. They reside within city limits if suitable habitat is available. In other states, the species reportedly inhabits woodland edges.

Behavior: The Western Milksnake is nocturnal, but does exhibit diurnal behavior. Their active season is from early April to late October. They breed from April to June, and females typically lay 2 to 24 eggs in one annual litter. They feed on small mammals, reptiles, and birds.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=ARADB1905B

 

Common Name: Common Sagebrush Lizard

Scientific Name: Sceloporus graciosus

Identification: TheCommon Sagebrush Lizard's back has brown, olive, or gray spiny scales with a paler stripe running down each side. The underside of females is white or yellow, but may develop orange-red suffusions on the neck and sides during the breeding season. Males have blue abdominal patches and blue mottling on the throat. Adults grow to be about six inches (15m) long with a maximum snout length of 2.5 inches (6.5 cm) and a tail that's about 1.5 times the length of the snout. Hatchlings are (2.3 to 2.8 cm) long. The eggs are white and leathery, and are about 0.5 inches (12 to 14 mm) in length by about 0.25 inches (6 to 8 mm) in breadth.

Habitat: They primarily live in sagebrush and other types of shrub lands because of their preference for open ground with some low bushes. However, they can be found in pinyon-juniper woodlands, open pine forests, and Douglas fir forests. This lizard often perches up to six and a half feet (2 m) above ground in low shrubs, rocks, logs, and trees;it uses rodent burrows, shrubs, and logs for cover.

Behavior: This species is an insectivore;its diet mainly consists of invertebrate although adults occasionally eat juvenile lizards. They use rodent burrows for overnight refuge, predatory escape, and winter hibernation. They emerge in March or April and remain active into October. They are diurnal. They breed between June and August before females lay one or two clutches of eggs about one inch (2.5 cm) deep in loose soil. Each clutch has two to eight eggs, which hatch after two months.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=ARACF14030

 

Common Name: Greater Short-horned Lizard

Scientific Name: Phrynosoma hernandesi

Identification: The Greater Short-horned Lizard has a broad, flat body. Its base color is generally brown or gray with a few darker brown spots. However, this may vary between regions;the species coloration more typically resembles the soil in which they live. They have spines on their head that are as long as they are wide at the base, and they have a single row of fringe scales on the sides of the abdomen. They have a very short tail that is about a third of the length of their body. Males usually have a proportionally longer tail than females, and have swelling at the base of their tail. Maximum total length is about (15 cm). Newborns are about one inch (2.5 cm) from snout to the base of their tail, but can be up to one and a half inches (3.8 cm) by the time of their first hibernation.

Habitat: This lizard is found a variety of habitats. They reside in sagebrush steppe, pine forest, juniper-pinon woodlands, and semi-arid short-grass prairie. They are common at high altitudes, and prefer rocky and sandy soils. They burrow in the soil or occupy rodent burrows when not active.

Behavior: This species is an insectivore, and is known to gorge itself on one prey species per meal. They are diurnal and mostly active during the warmer daylight hours. They enter hibernation before the first fall frost date, and emerge between late March and early June. Mating occurs shortly after. Males reach sexual maturity the summer after their first hibernation;female sexual maturity is not yet determined. The gestation period is about three months, and females give birth to 5 to 30 young in late July or early August. Females can live up to five years, but average male lifespan is unknown.

More Information: http://fieldguide.mt.gov:81/speciesDetail.aspx?elcode=ARACF12080

 

Common Name: Snapping Turtle

Scientific Name: Chelydra serpentine

Other Names: Common Snapping Turtle

Identification: The Snapping Turtle color varies from tan to dark brown to almost black. Their shells are hard and smooth with a serrated rear edge. There are three longitudinal ridges on the upper shell of juveniles;the hatchling shell is rough with conspicuous ridges. The head is large with a hooked upper jaw, and there are two barbels –sensory whisker-like organs –on the chin. They have long tails and necks. Maximum shell length ranges from 8 to 14 inches (20 to 30 cm) with a record length of 19.3 inches (49 cm). Their average weight ranges from 10 to 35 pounds (4.5 to 16 kg) with a record weight of 75 pounds (34 kg).

Habitat: In Montana, they have been observed in backwaters along major rivers, in small reservoirs, and in smaller streams and creeks with permanent flowing water and sandy or muddy bottoms. They heavily rely on aquatic environments and may resort to moving long distances on land if their pond or creek dries. Nests are built in soft sand, loam, vegetation debris, or even sawdust piles;they are usually located in open areas 100 yards (91 m) or more from water.

Behavior: Snapping turtles are generally docile in water, but will strike viciously if captured or cornered out of water. They are most active at night and in the early morning, and hibernate in cold weather. They mate from April to November and generally deposit 20 to 40 eggs in concave nests dug by the female. Incubation takes 75 to 95 days. Snapping turtles are omnivores;they eat a wide range of aquatic vegetation in addition to any vertebrate and invertebrate prey that can be captured in the water. Carrion is also consumed. The young actively forage for food, but adults prefer to ambush their prey by being still and seizing when the time is right.

More Information: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=araab01010

Last updated: April 17, 2017

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Little Bighorn Battlefield National Monument
P.O. Box 39

Crow Agency, MT 59022-0039

Phone:

(406) 638-3216

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