Sylvilagus aquaticusswamp rabbit

Geographic Range

Sylvilagus aquaticus can be found in most of the south-central United States and the Gulf coast. It is abundant in Alabama, Mississippi and Louisiana. Sylvilagus aquaticus can also be found in parts of South Carolina, Tennessee, Texas, Oklahoma, Missouri, Kansas, Illinois, Indiana, and Georgia. (Chapman and Feldhamer, 1981; Nowak, 1999)

Habitat

Sylvilagus aquaticus prefers to live in swampy lowlands, marshy areas, floodplains, tributaries of larger rivers, and cypress swamps. It is typically found close to water. Swamp rabbits spend the day in self-made depressions in tall grass, leaves, or anything that provides cover until their nocturnal foraging bouts. (Chapman and Feldhamer, 1981; Nowak, 1999)

Physical Description

Sylvilagus aquaticus is the largest member of its genus, the cottontails. However, its ears are smaller relative to other cottontails. The head and back are usually a mix of dark brown, rusty brown, or black. The throat, ventral surface and tail are white. A clear cinnamon-colored ring is visible around the eye. Males are slightly larger than females. Males weigh from 1816 to 2554 grams, with an average of 2235 g. Females are from 1646 to 2668 grams, averaging 2161 g.

Altricial young are born with fur up to 5 mm long with a weight of approximately 61.4 g. At birth, their fur color is dark (either brown or black) on their back, sides and throat. The tail, chin and abdomen are white. The head is a mix of tan and black. Their eyes are closed when born and open in 4 to 7 days. (Chapman and Feldhamer, 1981; Nowak, 1999; Scheibe and Henson, 2003)

  • Sexual Dimorphism
  • male larger
  • Range mass
    1646 to 2668 g
    58.01 to 94.03 oz
  • Range length
    452 to 552 mm
    17.80 to 21.73 in
  • Average length
    501 mm
    19.72 in

Reproduction

Swamp rabbits are synchronous breeders; all the members of a population breed at or around the same time. Prior to breeding a predictable sequence of behaviors occurs. First, females chase and/or threaten the males. Consequently, the males dash away. A jumping sequence follows. Finally, copulation occurs, and females begin chasing the males again. (Chapman and Feldhamer, 1981; Bond, et al., 2006)

Swamp rabbits usually begin breeding in mid- to late-February until August. Few exceptions are noted: in Texas, breeding occurs year round, in Louisiana, breeding can occur in every month except October.

Estrous behavior in unbred females follows a 12-day cycle, and estrus itself lasts about an hour in S. aquaticus. The gestation period lasts from 35 to 40 days (average of 36 to 37 days). They give birth to 1 to 6 offspring with an average of 3 offspring per litter.

Females make nests out of grass, dead twigs, and leaf litter above ground. These nests are typically 5.5 cm deep, 15 cm wide, and 18 cm high, and have side entrances. Sometimes, they use holes in large stumps or logs, Females also tend to build dummy nests before they build a real nest, which differs in that it is lined with fur before females give birth.

Young become sexually mature between 23 and 30 weeks old. Although juveniles are capable of breeding in their first year, most do not. Females have between 1 to 6 litters a year but 2 to 3 is most common. (Chapman and Feldhamer, 1981; Bond, et al., 2006)

  • Breeding interval
    Females typically have 2 to 3 litters per year.
  • Breeding season
    Breeding occurs from mid- to late-February in most places, but can occur year-round.
  • Range number of offspring
    1 to 6
  • Average number of offspring
    3
  • Range gestation period
    35 to 40 days
  • Average gestation period
    36.5 days
  • Range time to independence
    12 to 15 days
  • Range age at sexual or reproductive maturity (female)
    23 to 30 weeks
  • Range age at sexual or reproductive maturity (male)
    23 to 30 weeks

Mothers stay with their young until they leave the nest at 12 to 15 days old. She nurses them usually around dusk and dawn. The mother continues to feed the young after they leave the nest. Once the young are weaned there is no further parental care. Males do not care for young. (Chapman and Feldhamer, 1981; Fowler and Kissell, 2007)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female

Lifespan/Longevity

There is not much known about the wild or captive lifespans of Sylvilagus aquaticus because there have been very few studies examining this topic. Other Sylvilagus species live from 7 to 9 years maximum. ("Swamp Rabbit Ecology", 2000; Chapman and Feldhamer, 1981; Chapman, 2007; Bond, et al., 2006; Fowler and Kissell, 2007; Nowak, 1999)

  • Range lifespan
    Status: wild
    10 (high) years
  • Average lifespan
    Status: wild
    1.8 years
  • Average lifespan
    Status: wild
    1.8 years

Behavior

Sylvilagus aquaticus is most active at dawn, dusk, and at night. During the day they remain hidden and motionless, usually in a large hollow log or dense grass. They only move when a predator is too close to them. When a predator get too close they flee in a zig-zag pattern. They will jump into water and stay perfectly still, with only their nose above the water's surface.

Within a population of swamp rabbits, there is a linear dominance hierarchy among males, which helps limit fighting, once established. Only during breeding season do aggressive encounters occur between males, as they pursue a female. Females in the population have a mutual tolerance of one another. ("Swamp Rabbit Ecology", 2000; Chapman and Feldhamer, 1981; Nowak, 1999)

  • Range territory size
    0.01 to 0.08 km^2

Home Range

Swamp rabbits are territorial, and males practice "chinning" which is a pheromone-marking activity. These territories range in size from 0.01 to 0.08 square km (2.1 to 18.9 acres). ("Swamp Rabbit Ecology", 2000; Chapman and Feldhamer, 1981)

Communication and Perception

Swamp rabbits are normally not vocal except when they feel threatened. Males also leave scent marks to establish territories. Other Sylvilagus species also drum the ground with their rear feet to indicate aggression. ("Swamp Rabbit Ecology", 2000; Chapman and Feldhamer, 1981; Chapman, 2007)

Food Habits

Swamp rabbits are herbivores, foraging on a variety of plant materials, including grasses, sedges, shrubs, tree bark, tree seedlings, and twigs. Helm and Chabreck (2006) found that their preferred foods include savannah panicgrass (Phanopyrun gymnocarpon), false nettle (Boehmeria cylindrica), dewberry (Rubus sieboldii) and greenbrier (Smilax bona-nox). Swamp rabbits practice coprophagy. They have two kinds of fecal matter. The first is soft and green and still had nutrients in it--this is the kind that they eat because it gives them a chance to get more nutrients out of the food. The second kind of fecal matter are dark brown/black hard pellets--they do not eat these. (Chapman and Feldhamer, 1981; Choate, et al., 1994; Fowler and Kissell, 2007; Helm and Chabreck, 2006; Nowak, 1999)

  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • Other Foods
  • dung

Predation

There are few known predators of Sylvilagus aquaticus, but known predators include domestic dogs (Canis lupus familiaris), American alligators (Alligator mississippiensis), and humans (Homo sapiens). This species is the 2nd most hunted rabbit in the United States. They use a combination of cryptic coloration and "freezing" to avoid being detected and a rapid, irregular jumping pattern when fleeting to avoid capture. (Chapman and Feldhamer, 1981)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Swamp rabbits are important prey in their native ecosystems and their herbivory influences plant communities.

Swamp rabbits are affected by several parasites which include the trematodes Hasstilesia texensis and Hasstilesia tricolor, the cestodes Cittotaenia ctenoides, Cittotaenia variabilis, Multiceps serialis, and Raillietina stilesiellacestodes, the nematodes Graphidium strigosum, Nematodirus leporis, Obeliscoides cuniculi, Parasalurus ambiguous, Trichostrongylus calcaratus, and Trichuris leporis, fleas, ticks, and mites Haemaphysalis leporis-palustris. ("Swamp Rabbit Ecology", 2000; Chapman and Feldhamer, 1981)

Commensal/Parasitic Species
  • trematodes Hasstilesia texensis
  • trematodes Hasstilesia tricolor
  • nematodes Graphidium strigosum
  • nematodes Nematodirus leporis
  • nematodes Obeliscoides cuniculi
  • nematodes Parasalurus ambiguous
  • nematodes Trichostrongylus calcaratus
  • nematodes Trichuris leporis
  • cestode Cittotaenia ctenoides
  • cestodes Cittotaenia variabilis
  • cestodes Multiceps serialis
  • cestodes Raillietina stilesiellacestodes
  • mites Haemaphysalis leporis-palustris
  • fleas Siphonaptera)
  • ticks Acari

Economic Importance for Humans: Positive

Swamp rabbits are hunted for fur, meat, and for sport in the southeastern United States. ("Swamp Rabbit Ecology", 2000)

  • Positive Impacts
  • food
  • body parts are source of valuable material

Economic Importance for Humans: Negative

Swamp rabbits are usually harmless, but may occasionally damage crops and other vegetation. ("Swamp Rabbit Ecology", 2000)

  • Negative Impacts
  • crop pest

Conservation Status

The IUCN rank of this species is Lower Risk/Least Concern. Sylvilagus aquaticus has a global rank of "Secure" from NatureServe2007. In Alabama, Georgia, Mississippi, Texas, and Louisiana populations are considered secure. Swamp rabbits are vulnerable in Kentucky and Arkansas and imperiled in Oklahoma and South Carolina. (Chapman, 2007)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Annamarie Roszko (author), Radford University, Karen Francl (editor, instructor), Radford University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

coprophage

an animal that mainly eats the dung of other animals

crepuscular

active at dawn and dusk

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

saltatorial

specialized for leaping or bounding locomotion; jumps or hops.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Smithsonian Institution. "Smithsonian National Museum of Natural History" (On-line). North American Mammals. Accessed September 21, 2007 at http://www.mnh.si.edu/mna/image_info.cfm?species_id=366.

2000. "Swamp Rabbit Ecology" (On-line). Swamp Rabbit Ecology. Accessed November 09, 2007 at http://www.geocities.com/sylvilagus4/ecology.html.

Bond, B., J. Bowman, B. Leopold, L. Wes Burger, k. Godwin, C. Class. 2006. Swamp Rabbit Demographics, Morphometrics, and Reproductive Characteristics in Mississippi. Mississipps Academy of Science, Volume 51, issue 2: 123-128.

Chapman, B. 2007. The Land Manager's Guide to Mammals of the South. Durhan, NC: USDA Forest Service and Nature Conservancy.

Chapman, J., G. Feldhamer. 1981. Sylvilagus aquaticus. Mammalian Species, 151: 1-4. Accessed September 18, 2007 at http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/default.html.

Choate, J., J. Knock Jones, C. Jones. 1994. Handbook of Mammals of the Aouth-Central States. baton Rouge and London: Lousiana State University Press.

Forsyth, N., F. Elder, J. Shay, W. Wright. 2005. Lagomorphs (rabbits, pikas and hares) do not use telomere-directed replicative aging in vitro. Mechanisms of ageing and development, 126: 685-691.

Fowler, A., R. Kissell. 2007. Winter Relative Abundance and Habitat Associations of Swamp Rabbits in Eastern Arkansas. Southeatern Naturalist, Volume 6, issue 2: 247-258. Accessed September 21, 2007 at http://gw5kw3uf8g.search.serialssolutions.com/?&url_ver=Z39.88-2004&url_ctx_fmt=info:ofi/fmt:kev:mtx:ctx&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=Winter+relative+abundance+and+habitat+associations+of+swamp+rabbits+in+eastern+Arkansas&rft.auinit=A&rft.aulast=Fowler&rft.date=2007&rft.epage=258&rft.genre=article&rft.issn=1528-7092&rft.issue=2&rft.spage=247&rft.stitle=SOUTHEAST+NAT&rft.title=SOUTHEASTERN+NATURALIST&rft.volume=6&rfr_id=info:sid/www.isinet.com:WoK:WOS&rft.au=Kissel,+RE.

Helm, S., R. Chabreck. 2006. Notes on Food Habits of Swamp Rabbits in the Atchafalaya Basin, Louisiana. Mississippi Academy of Science: 129-133.

Nowak, R. 1999. Walker's Mammals of the World sixth Edition Volume 2. Baltimore and London: The Johns Hopkins University Press.

Platt, S., T. Rainwater. Notes on nesting and little size of wild swamp rabbits in Louisiana..

Scheibe, J., R. Henson. 2003. THE DISTRIBUTION OF SWAMP RABBITS IN SOUTHEAST MISSOURI. Southeastern Naturalist, Volume 3, Issue 3: 327–334.

Zollner, P., W. Smith, L. BRENNAN. 2000. Home Range Use by Swamp Rabbits (Sylvilagus aquaticus) in a Frequently Inundated Bottomland Forest. The American Midland Naturalist, Volume 143, Issue 1: 64-69.