Peninsula ribbon snake: Thamnophis sauritus sackenii

Taxonomic Classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Colubridae
Genus/Species: Thamnophis sauritus
Subspecies: Thamnophis sauritus sackenii
Common Name: Florida (Peninsula) ribbon snake

Listing Status

Federal Status: Not Listed
FL Status: No longer listed in Florida as of January 11, 2017, but is part of the Imperiled Species Management Plan.
FNAI Ranks: G5T1Q/S1 (Globally: Demonstrably Secure, Sub sp. Critically Imperiled [classification as a subspecies questioned]/State: Critically Imperiled)
IUCN Status: Not ranked

Physical Description

The Florida (Peninsula) ribbon snake is the only striped snake located in the Florida Keys. This species can reach a length of up to 40 inches (10.2 centimeters). The ribbon snake has a brown dorsum (back), with a black-striped, tan-bordered, mid-dorsum stripe that may be indistinct or completely absent, eight supralabial scales (scales that border the mouth), ridged back and side scales, yellow belly, and a tail that is 1/3 of their body length (Weaver et al. 1992, Florida Natural Areas Inventory 2001). Unlike ribbon snakes up north, the Florida ribbon snake is active year round requiring no hibernation (Ernst and Ernst 2003).

Life History

The diet of ribbon snakes primarily consists of fish, frogs, and lizards (Weaver et al. 1992, Ernst and Ernst 2003).

Breeding occurs between the months of April and June, with the young being born from July to September (Florida Museum of Natural History, n.d.). The ribbon snake is viviparous (has live birth instead eggs). Females can bear 3-26 offspring; however, the typical clutch size is 10-12 (Ernst and Ernst 2003). Females in the Lower Keys population have been found to have a clutch size of five to eight (Lazell 1989).

Habitat and Distribution

Peninsula Ribbon Snake Distribution MapThe protected population of the Florida ribbon snake inhabits Spartina (marsh grass) and mangrove marshes, as well as fresh water ditches, in the Lower Keys on Big Pine, Cudjoe, Little Torch, Middle Torch, No Name, Saddlebunch, Sugarloaf, and Upper Sugarloaf Keys (Lazell 1989, Weaver et al. 1992, museum and FNAI records).


The loss of hammocks and wetlands has probably lead to the population decline of Florida ribbon snakes, especially for ones that are restricted to habitats near fresh water sources with surrounding grass and shrubs.  However, they may be able to survive in cleared areas that are left to go through early ecological succession (changes in the ecological community), especially where fresh water sources remain.  They also face threats from hurricane storm surge. Storm surge from hurricanes can cause freshwater habitat to have increased salinity.  Other threats include sea level rise from global climate change and increased predation from invasive species.    

Conservation and Management

Biological Status Review (BSR) Adobe PDF
Supplemental Information for the BSR Adobe PDF

Other Informative Links

Florida Museum of Natural History External Website
Florida Natural Areas Inventory External Website



Printable version of this page Adobe PDF


Ernst, C. H. and E. M. Ernst.  2003.  Snakes of the United States and Canada.  Smithsonian Books, Washington, D.C., USA.  668pp.

Florida Museum of Natural History. (n.d.).  Peninsula Ribbon Snake.  Retrieved April 18, 2011,   from Herpetology: External Website

Florida Natural Areas Inventory.  2001.  Field guide to the rare animals of Florida.           

Lazell, J. D., Jr.  1989.  Wildlife of the Florida Keys: a Natural History.  Island Press, Covelo, California, USA.  254pp.

Weaver, W. G., S. P. Christman, and P. E. Moler.  1992.  Florida ribbon snake, Lower Keys population, Thamnophis sauritus sackeni (Kennicott).  Pages 162–165 in P. E. Moler,  editor.  Rare and endangered biota of Florida.  Volume III.  Amphibians and reptiles. University Press of Florida, Gainesville, Florida, USA.

Image Credit Photo courtesy of Kevin Enge, FWC

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Seagrasses have been used by humans for more than 10,000 years - to insulate houses, stuff furniture, thatch roofs and even fill seats in early models of Volkswagens.

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