- Federal Status: Not listed
- FL Status: State-Threatened (Lower Keys population only)
- FNAI Ranks: G5T1Q/S1 (Globally: Demonstrably Secure, Sub sp. Critically Imperiled [classification as a subspecies questioned]/State: Critically Imperiled)
- IUCN Status: Not ranked
The Florida brown snake is one of the smallest species of the genus Storeria (Bartlett and Bartlett 2003). This species can reach a maximum length of 12 inches (30.5 centimeters). Florida brown snakes also have a brown back, whitish belly with dark spots on the side of each belly scale, and rigged posterior (back side) and side scales (Florida Natural Areas Inventory 2001). During times of extreme cold periods, the brown snake will go into hibernation. Snakes hibernate during cold periods because they are cold-blooded animals. Their body temperature is regulated by the temperature of their surrounding environment (exothermic). Since snakes cannot generate their own heat they hibernate, usually in burrows, for protection against the cold.
The diet of the Florida brown snake primarily consists of earthworms, slugs, snails, frogs, small fish, and salamanders (Florida Museum of Natural History, n.d.).
Male brown snakes will locate females by following the pherormonal (chemical released to gain a response from the opposite sex) tract they leave when they are in heat. Females can be courted by more than one male, as the males will push each other off the females back while trying to mate. Female brown snakes are viviparous – they have live births instead of laying eggs (Ernst and Ernst 2003). Females in the Everglades have been reported to give birth to 6-13 young. A female on Little Torch Key was found with six embryos (Dalrymple et al. 1991, Lazell 1989). Females give birth from June to September, with most births happening in the months of July and August. Florida brown snakes reach sexual maturity at two or three years old (Ernst and Ernst 2003).
The Lower Keys population of the Florida brown snake can be found in tropical hardwoods hammocks and pine rocklands, specifically in Middle Torch, Little Torch, Sugarloaf, Big Pine, and No Name Key.
The loss of habitat has probably lead to the population decline of Florida brown 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). The dense network of roads on Pine Key has caused the population there to have a significant threat of road mortality. Non-native species can also be a threat including the non-native cane toad (Rhinella marina) and Cuban treefrog (Osteopilus septentrionalis), as they are known to feed on small snakes (Maskell et al. 2003, Meshaka et al. 2004). The Lower Keys population is vulnerable to hurricanes as the accompanying floods and sea water surges potentially could kill brown snakes and their prey. The Lower Keys population will have to face the impending threat of global climate change as the accompanying sea level rise will flood their habitat, potentially causing a decline in their population along with their prey.
Conservation and Management
The Florida brown snake (Lower Keys population) is protected as a state-Threatened species by Florida’s Endangered and Threatened Species Rule.
Biological Status Review (BSR)
Supplemental Information for the BSR
Bartlett, R.D. and Bartlett, P. 2003 . Florida Snakes A Guide to Their Identification and Habits. Gainesville, Florida. University Press of Florida. 182 pp.
Dalrymple, G. H., T. M. Steiner, R. J. Nodell, and F. S. Bernardino, Jr. 1991. Seasonal activity of the snakes of Long Pine Key, Everglades National Park. Copeia 1991:294–302.
Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Institution Press, Washington, D.C., USA. 668pp.
Florida Museum of Natural History. (n.d.). Florida Brown Snake. Retrieved April 26, 2011, from Herpetology: http://www.flmnh.ufl.edu/herpetology/fl-guide/storeriadvicta.htm
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.
Maskell, A. J., J. H. Waddle, and K. G. Rice. 2003. Osteopilus septentrionalis. Diet. Herpetological Review 34:137.
Meshaka, W. E., Jr., B. P. Butterfield, and J. B. Hauge. 2004. The exotic amphibians and reptiles of Florida. Krieger, Melbourne, Florida, USA. 166pp.