Eastern ratsnake

Pantherophis alleghaniensis

''Pantherophis alleghaniensis'', commonly called the eastern ratsnake, is a nonvenomous colubrid species endemic to North America.
Eastern Rat snake This was the first time that I had witnessed a snake not only climbing a vertical surface, but maintaining its grip whilst releasing part of its body to exhibit defensive behaviour. So impressive! Even though it was high up and a good distance away from me, it was clearly too close for comfort for this character. 
90 cm body length.  Colubridae,Eastern Rat Snake,Eastern ratsnake,Geotagged,Pantherophis alleghaniensis,Squamata,Summer,United States,Vertebrate,fauna,pennsylvania,reptile

Appearance

Adult snakes commonly measure 91.4 to 183 cm in total length , with a few exceeding 200 cm . The longest recorded total length to date is 256.5 cm .

Adults are shiny black dorsally, with a cream or white chin and throat. The belly has an irregular black and white checkerboard pattern, becoming uniformly slate gray towards the tail. Juveniles have dark dorsal blotches on a grayish ground color. The ventral pattern in juveniles is the same as in adults. The eyes are round with a black pupil, and particularly in juveniles but not always present in adults, a distinct white margin.

The dorsal scales are weakly keeled, and are arranged in 23 to 27 rows at midbody.

Males and females have the same coloration. Males have proportionally longer tails compared to females .
Yellow Rat Snake (Pantherophis alleghaniensis quadrivittata)  Animal,Circle B Bar Reserve,Colubridae,Colubrinae,Eastern Rat Snake,Eastern ratsnake,Florida,Lakeland,Nature,Pantherophis,Pantherophis alleghaniensis,Pantherophis alleghaniensis quadrivittata,Polk County,Reptile,Scaled Reptile,Serpentes,Snake,Squamata,United States,United States of America

Naming

Eastern rat snake, black rat snake, pilot snake, pilot rat snake,...hieroglyph snipped... chicken snake; and in Florida, yellow rat snake and Everglades rat snake...hieroglyph snipped...
Eastern Ratsnake (Juvenile) - Pantherophis alleghaniensis This is the largest snake species found in Connecticut.  It is nonvenomous.

Juveniles are light gray with brown/black blotches, a large head, and a black checkerboard belly.  They turn black with age and can reach 68 inches long (1.72 m).

Habitat: Spotted resting on a rock amidst vegetation at a neighborhood garden center. Eastern ratsnake,Geotagged,Pantherophis,Pantherophis alleghaniensis,United States,ratsnake

Behavior

The eastern rat snake is primarily active at night during the summer, and diurnal in the spring and fall. It is a terrestrial burrower and an excellent climber, and it may enter water. It is found under rocks and boards, and in trees under bark and within knot holes and palm fronds. The snake is a constrictor, and adults eat mainly endotherms while young eat mainly ectotherms. The diet includes rodents, lizards, frogs, and birds and their eggs....hieroglyph snipped... The snakes can also eat young chickens and chicks, hence the common name chicken snake.

Rat snakes are most vulnerable to predators as juveniles. Predators of ''P. alleghaniensis'' include hawks , great horned owls , foxes, raccoons, and domestic cats. Adult eastern rat snakes have few known predators other than humans. When frightened, a rat snake will freeze. If harassed, it will produce a foul-smelling musk to deter predators. If provoked further, it may coil, shake its tail, and snap at its attacker....hieroglyph snipped...

The snakes hybernate during the winter underground or in deep crevices. They may congregate in the same dens with other species of snakes, such as copperheads , black racers , and timber rattlesnakes . In Northern climes, the snakes are active from late April to October and mate in May or June. It is active earlier in the South....hieroglyph snipped...

Rat snakes reach sexual maturity in their fourth year. The snakes start to breed in May and June, earlier in the South. Males approach females to initiate breeding and may combat other males before breeding. About five weeks after mating, the female lays 5 to 27 eggs in hollow standing and fallen trees, compost and mulch heaps, sawdust piles, and decomposing logs. Incubation is about two months, and eggs hatch from July through September. Hatchlings are usually just over a foot long at birth, with the distinct gray and black pattern characteristic of juveniles.
Yellow Rat Snake This snake was hiding in a hollow log in an exhibit at the North Carolina Zoo Animal,Elaphe obsoleta,Elaphe obsoleta quadrivittata,Geotagged,Pantherophis alleghaniensis,Pantherophis obsoletus,Snake,United States,Western Rat Snake,Western rat snake,Winter,Yellow Rat Snake,Zoo

Habitat

The eastern rat snake occurs in a variety of habitats. These include farmlands, hardwood forests, forested wetlands, thickets and fields adjacent to forests, isolated urban woodlots and backyards that support populations of prey species. Eastern rat snakes do especially well in early successional and edge habitats. An arboreal species, the snakes get into human residences, where they may live in attics undetected. At the northern limits of their range, distribution appears to be restricted by the availability of suitable hibernating sites. In these climes, the snakes require southern exposures to receive maximal thermal benefit from the winter sun and to provide basking areas in early spring and late fall.The eastern rat snake is primarily active at night during the summer, and diurnal in the spring and fall. It is a terrestrial burrower and an excellent climber, and it may enter water. It is found under rocks and boards, and in trees under bark and within knot holes and palm fronds. The snake is a constrictor, and adults eat mainly endotherms while young eat mainly ectotherms. The diet includes rodents, lizards, frogs, and birds and their eggs....hieroglyph snipped... The snakes can also eat young chickens and chicks, hence the common name chicken snake.

Rat snakes are most vulnerable to predators as juveniles. Predators of ''P. alleghaniensis'' include hawks , great horned owls , foxes, raccoons, and domestic cats. Adult eastern rat snakes have few known predators other than humans. When frightened, a rat snake will freeze. If harassed, it will produce a foul-smelling musk to deter predators. If provoked further, it may coil, shake its tail, and snap at its attacker....hieroglyph snipped...

The snakes hybernate during the winter underground or in deep crevices. They may congregate in the same dens with other species of snakes, such as copperheads , black racers , and timber rattlesnakes . In Northern climes, the snakes are active from late April to October and mate in May or June. It is active earlier in the South....hieroglyph snipped...

Rat snakes reach sexual maturity in their fourth year. The snakes start to breed in May and June, earlier in the South. Males approach females to initiate breeding and may combat other males before breeding. About five weeks after mating, the female lays 5 to 27 eggs in hollow standing and fallen trees, compost and mulch heaps, sawdust piles, and decomposing logs. Incubation is about two months, and eggs hatch from July through September. Hatchlings are usually just over a foot long at birth, with the distinct gray and black pattern characteristic of juveniles.

References:

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Taxonomy
KingdomAnimalia
DivisionChordata
ClassReptilia
OrderSquamata
FamilyColubridae
GenusPantherophis
SpeciesP. alleghaniensis