Southern swimming snake
| Southern swimming snake | ||||||||||||
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| Scientific name | ||||||||||||
| Nerodia fasciata | ||||||||||||
| ( Linnaeus , 1766) |
The southern swimming snake ( Nerodia fasciata ), also banded water snake or banded swimming snake , is a semi - aquatic , nontoxic species of adder that occurs in southeastern North America. It belongs to the American water snakes of the genus Nerodia .
description
The southern swimming snake can grow up to 120 cm, with females with an average head-trunk length of 64 cm and a tail length of 16 centimeters being significantly larger than the males, which, however, are relative to the average head-trunk length of 54 cm have a longer tail (18 cm). With an average of 247 grams, the females are also significantly heavier than the males with an average weight of 114 grams.
The southern swimming snake can be colored gray, gray-green or brown. It has 11 to 35 large, dark spots on its back. Some specimens are so dark in color that drawing is barely noticeable. The adder has a flat head and is strongly built.
distribution
The southern swimming snake is common around Louisiana and occurs there over Arkansas and Mississippi in the north to Missouri and Illinois . In the west their range reaches Oklahoma and extends to the southeast of Texas . Along the south-east coast of North America, the distribution area stretches along the coast to Virginia , with the adder living all over Florida , where it is the most common species of the genus Nerodia .
The southern swimming snake needs moist habitats like lakes, ponds, rivers but also drainage ditches, marshland , swamps and saltwater meadows like the Everglades . However, she does need access to fresh water in order to drink.
Way of life
The southern swimming snake is diurnal for most of the year and is only active at night in midsummer and into October to avoid the heat. The snake spends about 60% of its life in the water and can dive for up to 24 minutes by lowering its heart rate from 33 beats per minute to just under 7. Depending on the weather it is from December to February in hibernation .
Comment fights were not observed in the southern swimming snake, the males actively look for females during the mating season. Depending on the food available and animal characteristics, sexual maturity occurs in the second or third year. The species is ovoviparous . Between July and September, pregnant females give birth to 7–40 young that are 18–24 centimeters long. The adder can live up to ten years.
While juvenile specimens of the southern swimming snake almost exclusively prey on fish, adult animals mainly eat frogs and other amphibians. Reasons for changing the food source can be that the amphibians, which are common in the habitats, are too difficult for juvenile animals to devour and this would also take too long. In addition to the greater expenditure of energy required for this, the snake would also be in danger of becoming prey itself for longer.
Subspecies
There are three subspecies:
- Nerodia fasciata confluens ( Blanchard , 1923)
- Nerodia fasciata fasciata ( Linnaeus , 1766)
- Nerodia fasciata pictiventris ( Cope , 1895)
Individual evidence
- ↑ a b c d e Nerodia fasciata in The Reptile Database
- ^ A b Raymond D. Semlitsch, J. Whitfield Gibbons: Body Size Dimorphism and Sexual Selection in Two Species of Water Snakes . In: Copeia . tape 1982 , no. 4 . American Society of Ichthyologists and Herpetologists (ASIH), 1982, p. 974-976 .
- ↑ a b nerodia fasciata in the endangered Red List species the IUCN 2012. Posted by: Hammerson, GA., 2007
- ^ A b c John E. Werler, James Ray Dixon: Texas Snakes: Identification, Distribution, and Natural History . University of Texas Press, 2000, ISBN 0-292-79130-5 , pp. 519 .
- ↑ a b pinesnake.de , accessed on January 24, 2012
- ^ SE Vincent, BR Moon, R. Shine, A. Herrel: The functional meaning of "prey size" in water snakes (Nerodia fasciata, Colubridae) . In: Oecologia . tape 147 , 2006, pp. 204-211 , doi : 10.1007 / s00442-005-0258-2 .
