|Swamp rabbit range|
The swamp rabbit (Sylvilagus aquaticus), or swamp hare, is a large cottontail rabbit found in the swamps and wetlands of the southern United States. Other common names for the swamp rabbit include marsh rabbit and cane-cutter. The common name, along with the species name “aquaticus” (meaning found in water), are suitable names for a species with a strong preference for wet areas and that will take to the water and swim.
Range and habitat
The swamp rabbit is found in much of the south-central United States and along the Gulf coast. It is most abundant in Alabama, Mississippi, and Louisiana, but also inhabits South Carolina, Tennessee, Texas, Oklahoma, Arkansas, Missouri, Kansas, Illinois, Indiana, and Georgia.
Swamp rabbits mainly live close to lowland water, often in cypress swamps, marshland, floodplain, and river tributaries. Swamp rabbits spend much of their time in depressions which they dig in tall grass or leaves, providing cover while they wait until the nighttime to forage.
S. aquaticus is the largest of the cottontail species, although its ears are smaller than other cottontails. Males are slightly larger than females. The head and back are typically dark or rusty brown or black, while the throat, ventral surface, and tail are white, and there is a cinnamon-colored ring around the eye. Their sides, rump, tail and feet are much more brownish, along with a pinkish-cinnamon eye-ring as opposed to the whitish eye-ring in eastern cottontails.
S. aquaticus males vary in weight from 1,816 grams (4.004 lb) to 2,554 grams (5.631 lb), with an average of 2,235 grams (4.927 lb); females vary from 1,646 grams (3.629 lb) to 2,668 grams (5.882 lb), averaging 2,161 grams (4.764 lb). S. aquaticus ranges in length from 452 millimetres (17.8 in) to 552 millimetres (21.7 in), with an average length of 501 millimetres (19.7 in).
Known predators of S. aquaticus are domestic dogs (Canis lupus familiaris), American alligators (Alligator mississippiensis), and humans (Homo sapiens). Even though their swimming abilities lack the speed to escape a pack of hunting dogs, swamp rabbits elude pursuers by lying still in the water surrounded by brush or plant debris with only their nose visible. The species is hunted for fur, meat, and sport, and is the second-most commonly hunted rabbit in the United States. Swamp rabbits have several adaptations to avoid predators: cryptic coloration, "freezing," and rapid, irregular jumping patterns.
Ontogeny and reproduction
S. aquaticus are synchronous breeders. Females give birth to altricial young. Young are born with well-developed fur but their eyes are closed and they are immobile. Their eyes have opened by day 3 and the young have begun walking. They are weaned and leave the nest after about 15 days. Young are sexually mature at 7 months and reach adult weight at 10 months. The nest in which the young are born consist of a slight depression in the earth that is filled with grasses mixed with rabbit hair.
Breeding season varies widely across the range of S. aquaticus, occurring anywhere between February and August, and can occur year round in Texas. Spermatogenesis has been noted to occur in S. aquaticus in Missouri in October and November. In a Mississippi study, groups of males harvested in December and February had the higher percentage of individuals with descended testes than those harvested in any other month (Class 2006). S. aquaticus exhibit induced ovulation and have an hour-long estrous period. The gestation period lasts 35 to 40 days. Females can have 1 to 3 litters a year with each litter consisting of 4 to 6 young. It has been documented that the occurrence of embryo resorption in seen in S. aquaticus. This loss of in-utero litters is thought to be attributed to some type of habitat disturbance such as flooding, which may cause overcrowding to occur.
Swamp rabbits are herbivorous; they eat a variety of foraged plants, including grasses, sedges, shrubs, tree bark seedlings, and twigs. They feed mainly at night but rain showers will often cause them to feed during daytime as well. A study has found that the preferred foods of S. aquaticus are savannah panicgrass (Phanopyrum gymnocarpon), false nettle (Boehmeria cylindrica), dewberry (Rubus sieboldii) and greenbrier (Smilax bona-nox).
Like other lagomorphs, they have a double digestion. Food passes through their gut twice, first producing soft, green feces (cecotropes) which still contain nutrients. These are eaten by the animal (coprophagy), and after further digestion the remains form drier, dark brown or black hard pellets, which are not eaten.
Rival males will often engage in aggressive encounters that sometimes become violent enough to kill one of the combatants. When fighting, males will stand on their hind legs and use their teeth and claws to inflict wounds on their opponent. They will also jump from the ground and strike with the sharp claws of the hind feet.
In 1979, the swamp rabbit species enjoyed a brief stint of notoriety when one swamp rabbit had a close encounter with Jimmy Carter. In April of that year, as President Carter was fishing on a small pond on his farm, a visibly agitated swamp rabbit approached his boat and tried to board. Carter used a paddle to splash water at the rabbit to dissuade it from swimming towards the boat.
- Hoffman, R.S.; Smith, A.T. (2005). "Order Lagomorpha". In Wilson, D.E.; Reeder, D.M. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 207–8. ISBN 978-0-8018-8221-0. OCLC 62265494.
- Smith, A.T. & Boyer, A.F. (2008). "Sylvilagus aquaticus". IUCN Red List of Threatened Species. Version 2009.2. International Union for Conservation of Nature. Retrieved 1 February 2010.
- "Swamp Hare". New International Encyclopedia. 1905.
- Reed, Don (September 2008). "Wildlife Species Profile Swamp Rabbit ( Sylvilagus aquaticus )" (PDF). Louisiana Wildlife News (5) (Louisiana State University Agricultural Center). Retrieved 25 November 2014.
- Sylvilagus aquaticus (swamp rabbit), Animal Diversity Web, University of Michigan Museum of Zoology.
- Courtney, Emily M. (5 September 2008). "Swamp rabbit ( Sylvilagus aquaticus )" (PDF). Mammals in Mississippi (3) (Department of Wildlife and Fisheries, Mississippi State University). Retrieved 11 December 2014.
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