By Janet Buresh
Geographic Range
Sylvilagus brasiliensis ranges from southern Mexico to northern Argentina. It commonly occurs in Amazonian Peru, Ecuador, and Bolivia and is common in eastern Brazil. In southern South America S. brasiliensis is found in both eastern and western Paraguay and in Argentina across the northern provinces and as far south as Tucuman province. (Eisenberg and Redford, 1999)
Biogeographic Regions:
neotropical 
(native ).
Habitat
Sylvilagus brasiliensis spends its time in moist forested areas. It also inhabits transitional forest and grasslands in the Chaco. (Mares, Ojeda, and Barqueq, 1989)
These animals are found in the following types of habitat:
temperate ; tropical ; terrestrial .
Terrestrial Biomes:
savanna or grassland ; forest .
Physical Description
(1.54 to 2.2 lbs)
Sylvilagus brasiliensis is a medium-sized rabbit, ranging in weight from 700 to 1000 g. The pelage is typically yellowish-brown, but some individuals are a darker brown or reddish color. The ventrum is whitish. This species has a characteristic russet patch on the dorsum of the neck. It also has pale spots above the eye and on the muzzle. (Eisenberg and Redford, 1999; Mares, Ojeda, and Barqueq, 1989)
Some key physical features:
endothermic ; bilateral symmetry .
Reproduction
These rabbits apparently breed once per year.
Females breed in August, producing their litters in September.
No information was found on S. brasiliensis mating systems. However, other species in the genus are apparently polygynous. Males may compete to establish dominance hierarchies, which in turn determine mating priority. The rigidity of these hierarchies varies between species. (Nowak, 1999)
Sylvilagus brasiliensis has a gestation period of 42 to 45 days. A small litter size of 2 is common. In Paraguay, a female with three embryos was collected. (Eisenberg and Redford, 1999; Macdonald, 2001)
Sylvilagus brasiliensis apparently reproduce only once per year. Females have a cycle in which the interbirth interval is about 270 days. In Misiones province, Argentina, females reproduce in September. (Eisenberg and Redford, 1999; Macdonald, 2001)
Rabbits of this genus are typically precocial. They are born with their eyes open, and are able to leave the nest by the age of 12 to 18 days. In some species, sexual maturity can be reached by the age of 80 days, although most species appear to wait until the following year to mate. Adult size may be attained by 23 to 30 weeks. (Nowak, 1999)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous .
No information was found on S. brasiliensis reproductive parental care. However, based upon the patterns in the genus, we can assume that the young are precocial, and that they leave the nest, becoming independent within three weeks of birth. (Nowak, 1999)
The female probably provides the bulk of parental care, nursing the young, grooming them, and keeping them safe in the nest until they are ready to disperse. There are no reports of male parental care in the genus. (Nowak, 1999)
Parental investment:
no parental involvement; altricial ; pre-fertilization (protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (protecting: female).
Lifespan/Longevity
There are no reports of the longevity of this species. However, congeners are known to live as long as 5 years in the wild, and have lived longer than 9 years in captivity. (Nowak, 1999)
Behavior
Sylvilagus brasiliensis is crepuscular and nocturnal. It is usually found solitary or in pairs. It may show a seasonal decline in abundance. (Eisenberg and Redford, 1999; Mares, Ojeda, and Barqueq, 1989)
Cottontail rabbits are quadrupedal, and move both by hopping and walking. They can swim when needed. They are known to keep very still, which is thought to be a possible mechanism to avoid the notice of predators. When chased by predators, these rabbits typically move in an erratic, zig-zag fashion, possibly helping them to escape larger animals which cannot follow their course. (Nowak, 1999)
Other members of this genus are not known to dig burrows, but females do dig holes or depressions for their nests. The nests are lined with grasses and fur. Females don't live in the nest with the young, they just huddle over it to nurse the babies. (Nowak, 1999)
Home Range
The home range size for this species has not been reported.
Key behaviors:
terricolous; saltatorial ; natatorial ; nocturnal ; crepuscular ; motile ; sedentary ; solitary .
Communication and Perception
No information was found on S. brasiliensis communication. However, other members of the genus are known to communicate with high pitched squeals and distress calls. As mammals, it is likely that they use scent cues. Tactile communication probably occurs between mates, rivals, and a mother and her offspring. (Nowak, 1999)
Food Habits
Sylvilagus brasiliensis forages on green vegetation of grass and shrubs. (Mares, Ojeda, and Barqueq, 1989)
Plant Foods:
leaves.
Predation
- tayra (Eira barbara)
- canids (Canidae)
- felids (Felidae)
Predation on S. brasiliensis has been reported in the western Amazon, in Acre, Brazil. A tayra, a neotropical mustelid, was seen running in pursuit of S. brasiliensis, but retreated when the observer was detected. Various canids and felids probably also prey on this species. (Calouro, 2000)
Other members of the genus Sylvilagus are known to remain very still for prolonged periods, possibly as a means of avoiding detection by predators using visual cues to catch prey. These rabbits are also known for their erratic flight from predators, in which they move in complex zig-zag patterns, possibly helping them to escape the predator. (Nowak, 1999)
Ecosystem Roles
Sylvilagus brasiliensis is likely prey for numerous medium and large carnivores. It probably affects vegetational communities through its foraging. (Macdonald, 2001)
Economic Importance for Humans: Negative
No information was found on an negative impact that this species might have on humans.
Economic Importance for Humans: Positive
Rabbits are an important game species in many parts of South America, and are an important source of protein in many rural areas.
Ways that people benefit from these animals:
food .
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
Sylvilagus brasiliensis is not protected under CITES or IUCN.
Other Comments
Sylvilagus brasiliensis is the only native rabbit in Argentina; other forms were introduced in the late 1800's. (Mares, Ojeda, and Barqueq, 1989)
This species is also commonly known as the forest rabbit and Tapiti. (Macdonald, 2001)
The Myxoma virus is commonly found in S. brasiliensis. Blood-feeding arthropod vectors, such as mosquitoes or fleas, mainly transmit this virus. Myzoma virus commonly causes a swelling of the face and head, resulting in mucoid cutaneous tumors. (Kerr, Best, and April, 1998)
Contributors
Janet Buresh (author), University of Wisconsin-Stevens Point. Chris Yahnke (editor, instructor), University of Wisconsin Stevens Point.
Nancy Shefferly (editor), Animal Diversity Web Staff.
