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THE RATSNAKES (Genus Elaphe) OF FLORIDA

(di William E. Haast and Robert Anderson)

This genus includes some of the most remarkable patterns to be found among the snakes. In cross section they are almost half-circled in shape with the flat abdomen meeting the sides of the body at an angle. The scales are both keeled and smooth. They are powerful constrictors and suffocate the prey before swallowing them.

CORN SNAKE (Elaphe guttata guttata)

Average length about 89 cm. Record length measured 182.9 cm.

This beautiful patterned snake is often called the “red rat snake”.

The background color is usually pale red. On the back is a series of large, crimson, saddle-like, blotches narrowly bordered with black; on many specimens there is a narrow, white margin outside of the black.

On each side of the body is a smaller series of similar blotches and beneath this a yet smaller series which terminates at the edges of the abdominal plates and displays more of an orange than a red color. In contrast to the upper surface pattern, the abdomen is white with large black squares. On the neck and immediately behind the head is a red blotch extending forward in two branches to the top of the head and then forward to form a wedge-shaped marking terminating between the eyes. A red stripe crosses the brow or forehead and from behind each eye runs a line of similar color, bordered with black and terminating at the angle of the mouth. The upper and lower lip plates are white, with black borders. The head, in proportion to the thickness of the body, is considered small and barely distinct from the neck.

Habits and habitats

A good climber and often ascends small trees and bushes in search of young, or sleeping, adult birds. It is capable of ascending up the large trunk of a rough-barked tree with a crawling motion. The red rat snake is unpredictable when being handled –9 out of 10 times it will not attempt to bite. When on the ground it will coil and strike viciously. If left alone it seek shelter in the nearby brush. The habitats include; deep sand pinelands, flat woods, hammocks, fields, desert building, and piles of debris. The rat snake is a powerful constrictor and will kill its prey by suffocation before swallowing it. Prey consist mostly of rodents, young rabbits, and birds. It is oviparous and will lay 10 to 24 yellowish-white eggs under a log, flat stone, or debris. The young duplicate the parents in pattern but are much more striking in color.

Florida range includes the entire States except the Keys.

PINK RAT SNAKE (Elaphe guttata rosaea)

A subspecies that is very similar to the red rat snake from which its less intense pattern color and its plain or almost plain, yellowish abdomen distinguish it. The background color is usually buff to cream and spots and blotches mostly pinkish, with lower, lateral series of spots almost unnoticeable. The abdomen varies from yellow to a light orange and the black squares are faded becoming very faint towards the base of the tail.

Habits and habitats

The same as those of the red rat snake.

Florida range is restricted to Dade, Monroe, and Collier counties, and southward to the Keys.

YELLOW RAT SNAKE (Elaphe obsoleta quadrivittata)

Average length about 114 cm. Record length measured 213.4 cm.

Background color bright yellow or pale brown, with 4 dark brown stripes-two on the back and one on each side of the body. The preceding description only applies to an adult specimen. With the young of the species we have a remarkable example of one of a number of species of snakes that undergo a complete color transformation while attaining maturity.

Upon hatching the young yellow rat snake has a vivid pattern of a pale grey background with dark brown blotches. It gradually transforms into a yellow snake with 4 longitudinal stripes. About one year will have passed before the young snake takes on the yellow characteristic color. At this time, along the borders of the larger blotches of the back run two, smokey, indistinct stripes. In about the second year, the yet immature, species will display the patterns of both the young and the adult phases. The complete transition takes almost 3 years. At this point the snakes will have reached a length of about 152 cm. During this transitional period the yellow rat snake will confuse the layman to no end as to what kind of snake it is.

Habits and habitats

This snake is semi-arboreal in habits and has been observed at a considerable height, in a large oak tree feeding on young birds in a nest. It has also been observed coiled on a branch, of a smooth, bark tree trunk, 25 feet above the ground. It also has a habit of climbing among the rafters of old buildings and chicken coops where it will prey upon the young of chickens and raid the nests of eggs. One large specimen has been observed devouring six large chicken eggs, and another taking eight eggs. Eggs are swallowed whole, but as the eggs pass about 36 cm. Down the snake’s throat that portion of the body is pressed against the ground an by a strong muscle contraction of the swallowing muscles, the shell of each egg is broken, the shell fragments are swallowed along with the contents of the eggs, and are digested. The yellow rat snake is bold and comparatively fearless as compared with most species of snakes. When surprised it will crawl to safety. However when molested it will assume a position with its head and neck raised some distance from the ground, the neck in a close S-loop, ready for a long strike at the intruder. During this time the tip of the tail is vibrating with such rapidity that it appears as a blur. Its bite is vicious and capable of inflicting razor-like lacerations upon the skin that usually bleeds profusely. When handled, this snake emits a strong, offensive odour that is voluntarily ejected from a pair of musk glands that are positioned at the base of the tail. Habitats are many and well-distributed. Open woodlands and fields, deserted and occupied buildings, and roadsides bordered with brush. Rodents like mice, and rats are its main source of food. Prey is suffocated by constriction and then swallowed.

Yellow rat snakes are oviparous and lay up to 24 white eggs. The young, as mentioned earlier, do not resemble the parents. A newly hatched young will measure about 30 cm. In length.

Florida range includes the north western part of the State and extends southward along the east cost then covers the peninsula’s midsection and southward to Dade and Collier counties. There are no records of Elaphe obsoleta quadrivittata recorded from the panhandle.

EVERGLADES RAT SNAKE (Elaphe obsoleta rossalleni)

Average length about 122 cm.  The record length measured 221 cm.

Very similar to the adult yellow rat snake in body but can be distinguished by its bright orange, sometimes orange-brown, or orange-yellow, background color and the bright orange, to orange-yellow, abdomen and throat. The stripes, although present, are grey and somewhat subdued or almost faded out. In this species the tongue is red.

Habits and habitats

Habits are the same as those of the yellow rat snake except that this snake is an excellent swimmer and uses the water as an avenue of escape. But the habitats are confined to the Everglades where it frequents the tall saw grass; along the waterways, and in brush and small trees. It has been observed in the tall Australian pines along the roadsides in the Everglades area. The young are hatched from eggs and are born with a background color of pinkish orange, or buff-pink, whit light greyish-brown blotches that are in dull contrast with the background color.

Florida range includes northern Dade and Monroe counties and northward to Palm Beach, Glades, and Charlotte counties.

KEY RAT SNAKE (Elaphe obsoleta deckerti)

Also called Deckert’s rat snake; another snake that resembles the yellow rat snake but can be identified by the yellow chin and throat, a usually pink abdomen, and red to pink eyes. Unlike the Everglades rat snake, the Key or Deckert’s rat snake has well defined dark brown to black, longitudinal stripes, a pink instead of orange abdomen, a black tongue, and a yellowish-brown on the back instead of orange.

Habits and habitats very similar to the Everglades species. However, this snake is more confined to the southern most parts of Florida from the Miami area to Cape Sable and Key Largo where it often frequents the salt marshes.

GRAY RAT SNAKE (Elaphe obsoleta spiloides)

Average length about 127 cm. Record length measured 214 cm.

In Florida this snake is often referred to as the “white oak snake”.

This large snake has a background color of medium or dark gray in some while in others pale brown, gray, or almost white. Florida specimens are usually light gray white. It is strongly blotched with various shades of gray or brown but are always in strong contrast of the back or dorsum are alternated with small lateral spots. The scales are somewhat keeled. The abdomen is yellowish-white to gray and, more or less, blotched with black except the forward part which may be entirely without. Side of head with a single, narrow, black stripe from back of the eye to the angle of the mouth. The lip plates are white, bordered with black. The eyes are almost silvery in color.

Habits and habitats

A large, rather ill-tempered, snake that seems to prefer the open woodlands and grassy fields where it feeds on small mammals, and birds. It is a powerful constrictor when killing prey. It is oviparous in reproduction habits and the young are colored and patterned like the parents.

Florida range includes the panhandle and eastward to Leon and Union counties in the northern part of the peninsula.

GULF HAMMOCK RAT SNAKE (Elaphe obsoleta williamsi)

A subspecies of the gray rat snake that is referred to as the “Gulf hammock snake” by many Florida herpetologist. It is blotched like the gray rat snake, but also has 4 dark, longitudinal stripes that connect the series of dorsal and lateral blotches. The background color is whitish with all of the dark markings in strong contrast.

Habits and habitats are like those of the gray rat snake. The Florida range, however, is Levy County, mainly in the Gulf Hammock region.

Ultimo aggiornamento Domenica 21 Novembre 2010 22:20