Lower Keys Rabbit: Sylvilagus palustris hefneri

Taxonomic Classification

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Lagomorpha
Family: Leporidae
Genus/Species: Sylvilagus palustris
Subspecies: Sylvilagus palustris hefneri
Common Name: Lower Keys rabbit (also known as Lower Keys marsh rabbit)

Listing Status

Federal Status: Endangered
FL Status: Federal-designated Endangered
FNAI Ranks: G5T1/S1 (Globally: Demonstrably Secure, Sub sp. Critically Imperiled/State: Critically Imperiled)
IUCN Status: LC (Least Concern)

Physical Description

The Lower Keys rabbit is the smallest of three subspecies of marsh rabbits.  This species can reach a length of 14-16 inches long (3.5-4 centimeters).  This species has a brown dorsal (back); gray belly, small ears, and a grayish-brown tail (Florida Natural Areas Inventory 2001).

Life History

The diet of the Lower Keys rabbit primarily consists of a variety of herbaceous plants, such as the bushy seaside tansy (Borrichia frutescens) (U.S. Fish & Wildlife Service 1999). 

Breeding occurs throughout the year; however, breeding peaks from December through June.  Female rabbits can go through a pseudo-pregnancy (fake pregnancy), if they mate with an infertile male (Thompson and Frost 2008).  The total gestation period ranges from 30-37 days (Smithsonian National Museum of Natural History, n.d.).  Rabbit nests are lined with grass and breast fur and located on the ground in thickets, stumps or logs. On average, a rabbit will produce six to seven litters per year with two to four young in each litter.  Rabbits are born blind and will not open their eyes until the fourth or fifth day after birth.  Females will tend to their offspring until they are able to be self-reliant at 12 to 15 days old.  Rabbits can live up to four years in the wild; however, most do not live past one year (Thompson and Frost 2008).

Habitat and Distribution

Lower Keys Rabbit Distribution MapLower Keys rabbits inhabit higher elevation levels around fresh and salt water marshes. This species is endemic to the Florida Keys from Big Pine Key to Boca Chica Key (Florida Natural Areas inventory 2001).


The main threats to the Lower Keys rabbit is habitat destruction and fragmentation.  Habitat destruction has been extensive in the Florida Keys, and the rabbit has lost 50% of its habitat in the last 25 years (Faulhaber and Smith 2008).  Human development has increased along the coast and islands, which destroys habitats that were once uninterrupted.  Habitat fragmentation is also a threat with increased development, as the habitat is broken off into different sections, segregating populations.  Small segregated populations can be difficult to sustain, leading to extirpation.  Invasive vegetation decreases available food for the rabbit by out-competing the native vegetation that rabbits feed on.  Rabbits are also threatened by sea level rise from global climate change.  As ground nesters, a dramatic rise in sea level would inundate their habitat and nesting areas.  Hurricanes pose a threat as the accompanying storm surge can also inundate their habitat and nesting area.  Other threats include predation from domesticated and feral cats, hits from cars, and illegal poaching (Faulhaber and Smith 2008, Florida Natural Areas Inventory 2001). 

Conservation and Management

The Lower Keys rabbit is protected as an Endangered species by the Federal Endangered Species Act and as a Federally-designated Endangered species by Florida’s Endangered and Threatened Species Rule External Website.

Federal Recovery Plan External Website

Other Informative Links

Animal Diversity Web External Website
Florida Natural Areas Inventory External Website
FWC Species Information Adobe PDF
International Union for Conservation of Nature External Website
Smithsonian National Museum of Natural History External Website
U.S. Fish and Wildlife Service Species Conservation Guidelines External Website
U.S. Fish and Wildlife Service Multi-Species Recovery Plan for South Florida External Website



Printable version of this page Adobe PDF


Florida Natural Areas Inventory.  2001.  Field guide to the rare animals of Florida. http://www.fnai.org/FieldGuide/pdf/Sylvilagus_palustris_hefneri.PDF External Website

Faulhaber, C.A. & Smith, A.T. 2008. Sylvilagus palustris. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. www.iucnredlist.org External Website. Downloaded on 24 May 2011.

Smithsonian National Museum of Natural History. (n.d.). Sylvilagus palustris hefneri. Retrieved May 24, 2011, from North American Mammals: http://www.mnh.si.edu/mna/image_info.cfm?species_id=368 External Website

Thompson, L. and S. Frost. 2008. "Sylvilagus palustris" (On-line), Animal Diversity Web Accessed May 27, 2011 http://animaldiversity.ummz.umich.edu External Website

U.S. Fish & Wildlife Service. (1999, May 18). Lower Keys Rabbit Sylvilagus palustris hefneri.  Retrieved from Multi-Species Recovery Plan for South Florida: http://www.fws.gov/verobeach/MSRPPDFs/LowerKeysRabbit.pdf External Website

Image Credit FWC

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