Nerodia floridana

Nerodia floridana
Juvenile Florida green watersnake
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Family:	Colubridae
Genus:	Nerodia
Species:	N. floridana
Binomial name
Nerodia floridana (Goff, 1936)
Synonyms[2]
Natrix cyclopion floridana Goff, 1936 Nerodia cyclopion floridana — Mehrtens, 1987 Nerodia floridana — Conant & Collins, 1991

Nerodia floridana, commonly known as the Florida green watersnake, or eastern green watersnake, is a harmless species of snake in the subfamily Natricinae of the family Colubridae. The species is native to the southeastern United States.

Description

N. floridana is the largest watersnake in North America. Fully grown it will typically reach 76–140 cm (30–55 in) in total length (including tail), with the record-sized specimen having measured 188 cm (74 in) in total length.[3] Its coloration is solid grey or greenish-brownish with a white or yellow belly in adults, which darkens in color under the tail. Encircling the lower half of the eye is a row of scales, which is separate from the upper lip scales. Among all southeastern U.S. snakes, only the green water snake has this feature.[4] Juveniles have typically, about 50 dark crossbars on the dorsum and on the sides, which fade gradually with age.[5]

Geographic distribution and habitat

N. floridana is found in Alabama, Florida, Georgia, and South Carolina.[2] In southern South Carolina it is commonly found in open, marshy wetland areas. It is rarely found in rivers or streams.[4] It prefers choked vegetation and calm waters such as swamps and marshes. It is also generally found in lakes, ponds, ditches, and occasionally in brackish water.[6]

Behavior and ecology

In southern Florida, N. floridana is active year round. Like other water snakes of the southeastern U.S., N. floridana hibernates during the winter in the northern, coldest parts of its range. In colder areas and months, the snake can be seen basking outdoors on sunny days. In southern Florida, it often travels overland on rainy days.[4]

Diet

Little is known about the diet of N. floridana. Most reports suggest that its diet consists primarily of fish, including sunfish, crappies, and small bass. It also preys upon frogs, especially pig frogs, tadpoles, and salamanders. Little is known about its methods for finding prey, but like other water snakes, N. floridana swallows its prey alive.[4][6]

Reproduction

N. floridana bears live young by ovoviviparity similar to other North American water snakes. A few observations have been made of matings in late winter or early spring. Females generally have very large litters and give birth in the summer. The size of the litter ranges from 20 to 40, and the young are typically born from June to September.[6] The record litter for the species was 132 babies, taken from a dead female.[4]

Threats

Despite the huge litters of N. floridana, most juveniles never reach adulthood. Common predators in its wetland habitat include river otters, hawks, herons, egrets, ospreys, turtles, kingsnakes, alligators, and several species of predatory fish. When threatened, the Florida green watersnake's first impulse is to escape, and if captured, it will then resort to biting or releasing a strong musk from its scent glands.[4]

Conservation status

The species N. floridana is abundant in many wetland areas, except for the northern areas of its range. Thousands of N. floridana die annually on Florida roads and highways near wetland habitats.[4] In Georgia and South Carolina N. floridana is considered "state imperiled".[6]

References

1. Hammerson, G.A. (2007). "Nerodia floridana". IUCN Red List of Threatened Species. 2007: e.T63855A12722497. doi:10.2305/IUCN.UK.2007.RLTS.T63855A12722497.en. Retrieved 20 November 2021.
2. Species Nerodia floridana at The Reptile Database www.reptile-database.org.
3. "Nerodia floridana ". University of Florida
4. Gibbons, Whit; Dorcas, Mike (2005). Snakes of the Southeast. University of Georgia Press. ISBN 978-0820326528.
5. South Carolina Department of Natural Resources: Florida green watersnake
6. University of Georgia, Herpetology Program

Further reading

• Conant R, Bridges W (1939). What Snake Is That? A Field Guide to the Snakes of the United States East of the Rocky Mountains. (With 108 drawings by Edmond Malnate). New York and London: D. Appleton-Century. Frontispiece map + viii + 163 pp. + Plates A-C, 1-32. (Natrix cyclopion floridana, pp. 91–92 + Plate 15, figure 43).
• Goff CC (1936). "Distribution and variation of a new subspecies of water snake, Natrix cyclopion floridana, with a discussion of its relationships". Occasional Papers of the Museum of Zoology, University of Michigan (327): 1–9 + one plate.
• Schmidt KP, Davis DD (1941). Field Book of Snakes of the United States and Canada. New York: G.P. Putnam's Sons. 365 pp. (Natrix cyclopion floridana, pp. 216–217).
• Wright AH, Wright AA (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock Publishing Associates, a division of Cornell University Press. 1,105 pp. (in 2 volumes). (Natrix cyclopion floridana, pp. 474–477, Figure 140 + Map 38 on p. 467).