- 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)
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).
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).
Lower 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).
Florida Natural Areas Inventory. 2001. Field guide to the rare animals of Florida. http://www.fnai.org/FieldGuide/pdf/Sylvilagus_palustris_hefneri.PDF
Faulhaber, C.A. & Smith, A.T. 2008. Sylvilagus palustris. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. www.iucnredlist.org. 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
Thompson, L. and S. Frost. 2008. "Sylvilagus palustris" (On-line), Animal Diversity Web Accessed May 27, 2011 http://animaldiversity.ummz.umich.edu
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