The marsh rabbit (Sylvilagus palustris) is a small cottontail rabbit found in marshes and swamps of coastal regions of the Eastern and Southern United States, from Virginia to the lower Florida Keys. Being a small brown rabbit, it is similar in appearance to the widespread eastern cottontail (Sylvilagus floridanus), but is characterized by its smaller ears, legs, and tail, as well as its grayish-brown underparts.
Marsh rabbits are common throughout their range, except for in the Everglades, where the invasive Burmese python has reduced their numbers, and the lower Florida Keys, where the subspecies known as the Lower Keys marsh rabbit (Sylvilagus palustris hefneri) is threatened by rising sea levels and human development of the land. They prefer to live in marshes, swamps, and alongside coastal waters and rivers, as they are excellent swimmers. The marsh rabbit is often compared to the aquatic swamp rabbit (Sylvilagus aquaticus), which is found along the Gulf coast and further inland in the southeastern United States, though the swamp rabbit has larger ears, tail and legs, as well as a distinctly white underside of its tail.
Like other rabbits, the marsh rabbit is a herbivore, and will eat the leaves and bulbs of various aquatic plants, such as cattails and marsh pennywort. It will also eat crops, such as carrot, sweet potato, and sugar cane, which has caused it to be labeled as a pest. The marsh rabbit is nocturnal and will dig out shelters in the ground with its long toenails to hide and rest in during the daytime, and though it does not create burrows like some other rabbits, it will take advantage of those left behind by other animals. The rabbit's long nails also help it to swim. Some predators of the marsh rabbit include birds of prey, such as owls and the northern harrier, and land animals like bobcats and snakes. Rabbit ticks and other parasites are often found on and in the marsh rabbit, and cases of tularemia and mange are known from it as well.
Humans have some history with marsh rabbits, with the species' diet of aquatic and cultivated plants making it considered as a pest, especially in Florida where sugar cane is grown. Some states regulate marsh rabbits as game animals for hunting, where patches of dried grass may be burned to flush them out. As food, the marsh rabbit may be stewed, or it may be marinated, floured, and fried. The term "marsh rabbit" is used in some restaurants in the eastern United States as a euphemism for muskrat meat. Due to how common it is across most of its range, the marsh rabbit is classified as a least-concern species by the International Union for Conservation of Nature.
Taxonomy, etymology and phylogeny
Taxonomy
The marsh rabbit was first described by the American naturalist John Bachman in 1837, who had discovered the species in South Carolina 15 years prior and gave the specimen he recovered to the Charleston Museum. As the specimen had gone undescribed by all other naturalists during that period, Bachman used his knowledge of the rabbits he had examined since then to describe the new species Lepus palustris, the "swamp hare". Bachman noted it as being different from the snowshoe hare (Lepus americanus) in that it would readily swim through bodies of water rather than going around them. Its type locality was restricted to be "eastern South Carolina" in 1901. In 1904, it was placed in the genus Limnolagus by American mammalogist Marcus Ward Lyon Jr.; the name was previously used as the subgenus of both the marsh rabbit and swamp rabbit (Sylvilagus aquaticus) in an 1899 work by the Swiss physician Charles Immanuel Forsyth Major. Edward William Nelson, an American naturalist, clarified several years later in 1909 that the species belonged to Sylvilagus and grouped it alongside the larger swamp rabbit, which is native to the southeastern United States and Gulf Coast as far east as South Carolina and is not synoymous with the marsh rabbit.
The marsh hare's scientific name, Sylvilagus palustris, is derived from Latin. The genus name sylvilagus is a combination of () and (), meaning "hare of the woods". The species name means "marsh loving".
Fossil record Fossils of the marsh rabbit are known from Florida, South Carolina, and Georgia. The oldest of these fossils may be from the Rancholabrean age of North America, about 774,000 years ago, but most are found in deposits that are dated to the late Pleistocene age. Much of the fossil evidence of marsh rabbits comes from deposits in the coastal plains of Melbourne, Florida, and is largely between 125,000 and 75,000 years old. An increase in rain throughout this region in the period 6,500 to 5,000 years ago is considered the main cause of the marsh rabbit's spread throughout its current distribution.
Phylogeny In the subgenus Tapeti in the genus Sylvilagus, marsh rabbits and swamp rabbits share a chromosomal karyotype derived from a common ancestor and have a diploid number of 2n=38. Molecular data analysis from sequencing the mitochondrial 12S ribosomal RNA gene, which has been considered particularly useful in determining genetic relationships between species, confirms that S. palustris and S. aquaticus are sister taxa.
The following cladogram showing the genetic relationships between the marsh rabbit and other cottontail rabbits is based on nuclear and mitochondrial gene analysis:
Subspecies Three subspecies of Sylvilagus palustris have been identified: Carolina marsh rabbit (Sylvilagus palustris palustris) – nominate subspecies; marsh rabbit of mainland regions from northwest Florida to southeast Virginia. Florida marsh rabbit (Sylvilagus palustris paludicola) – found in peninsular Florida down to the upper Florida Keys. Lower Keys marsh rabbit (Sylvilagus palustris hefneri) – classified as endangered. Molecular evidence points towards this subspecies potentially being only classified as a group of isolated populations, not a distinct subspecies.
Description
Marsh rabbits have blackish brown or dark reddish fur on their back, head, and upper body. The belly is a dingy brownish gray in most cases, but can also have a dull white appearance in mainland rabbits. The leading edges of the ears display small black tufts with ochre on the inside. The rough hair on the rabbit's back may be fringed with black hairs. The black portions of the upper parts often change to a dull grayish buff in spring and summer months, returning to a reddish or ochre color in fall, followed by darker black in the winter. Marsh rabbits of peninsular Florida typically display darker and redder colors with a cinnamon-rufous nape, feet, and legs. Juveniles display much darker and duller colors than adults.
Marsh rabbits are typically smaller than eastern cottontail (Sylvilagus floridanus) rabbits, though they are otherwise similar in their general appearance. Adults from the Florida peninsula weigh approximately with a total length upwards of . Adults from the mainland regions typically grow larger, weighing up to and reaching more than in length. The hind feet of the average mainland marsh rabbit are also larger, at compared with for the typical specimen of the Florida peninsula. Another feature observed in specimens from southern Florida is melanism. These individuals exhibit completely black phenotypic coloration that does not change seasonally.
The most easily identifiable feature that distinguishes marsh rabbits from swamp rabbits and cottontails is that the underside of the tail is almost never white but more brownish gray. The short ears and legs of a marsh rabbit are much smaller than that of a swamp rabbit. The tail is also much reduced from the bushy tail seen in other cottontails. The front of its skull tapers more quickly than the swamp rabbit as well. Long toenails, used for digging, are found in both the swamp and marsh rabbit, though the marsh rabbit's are 13% longer on average when comparing the two species. The marsh rabbit's dental formula is —two pairs of upper and one pair of lower incisors, no canines, three upper and two lower premolars on each side, and three upper and lower molars on either side of the jaw.
Habitat and distribution
The marsh rabbit is found in wet areas of low elevation from southeast Virginia through Florida to the Florida Keys, with populations occurring throughout eastern North and South Carolina, southeast Georgia, and southeast Alabama as well. Each subspecies is found in particular parts of the broader range. The Carolina marsh rabbit (S. p. palustris) ranges from the Dismal Swamp, Virginia, along the eastern coast to northern sections of Florida and through the Gulf Coast into Mobile Bay, Alabama. It occupies coastal lowland areas, swamps, and rivers and is rarely found more than forty miles from the coast. The Florida marsh rabbit (S. p. paludicola) occupies the peninsular region of Florida, from south of the Florida Panhandle to the upper Keys. There is a region north of Miami along the east coast where this subspecies is not found. The endangered Lower Keys marsh rabbit (S. p. hefneri) is only found in the southern Florida Keys.
The marsh rabbit commonly inhabits brackish and freshwater marshes, mainly of cattails and cypress. In southern Florida, they commonly occupy sandy islands and mangrove swamps. They are strictly limited to regions with ready access to water, unlike most rabbits. Often, they will enter tidal marshes, but remain near high ground for protection. Normal hiding spots include dense thickets of magnolia, blackgum (Nyssa sylvatica), sweetgum (Liquidambar styraciflua), briers, and cattails.
Ecology and behavior
Behavior Marsh rabbits are most active nocturnally; they spend most of the daylight hours resting in hidden areas. Frequent hiding spots include dense thickets, hollow logs, and stands of cattails and grasses. They have also been known to take advantage of the abandoned burrows of other animals. During the day, if not using the burrow of another animal, a marsh rabbit will create a depression in the earth among dense vegetation, under thickets, or within tree cavities. This depression is known as a form, and is a place where a rabbit will often return with food and other items (such as the leftover molts of crayfish or plastrons from Florida box turtles) to chew on, though forms from other rabbits may be taken if convenient. They are assisted in the digging of forms and nests through the use of their long toenails. Marsh rabbits frequently make runway trails in dense vegetation along marsh edges. These trails can be identified easily as the rabbits mark active runways with fecal pellets, though pellets are deposited on raised surfaces such as stumps and rocks as well. They may travel up to in a day.
One distinguishing habit of marsh rabbits is that they walk on all fours, placing each foot down alternately like a cat. Although they can hop like all rabbits, they are more agile in dense vegetation with this walking tendency. This smaller gait has been measured at between steps. Running is also seen in marsh rabbits, where they will scurry along the ground with the head lowered.
Marsh rabbits are more aquatic than swamp rabbits, as they are not known to inhabit forests. They take to water readily and are excellent swimmers. To aid in swimming, the hind legs have less fur and longer nails than typical cottontails. When not concealed in dense thickets, the rabbits will stay submerged in muddy water with only their eyes and noses exposed and ears laid back flat. When they have been spotted, they will readily take to water and swim quickly to a new hiding spot or floating vegetation. Because marsh rabbits possess very short hind legs, they typically rely on doubling back and turning when running to evade predators. This often leads to easy capture by dogs. When flushed out of hiding spots, they may squeal as they escape.
Ecology