Dolichotis salinicola
Chacoan mara

Dolichotis salinicola ranges from the Chaco of Paraguay and the southernmost portion of Bolivia, south into northwestern Argentina and its Cordoba Province. (Dunnum, et al., 2010; Honacki, et al., 1982; Redford and Eisenberg, 1992; Wilson and Reeder, 2005)

Chacoan maras are endemic to the Chaco, a large area in Paraguay consisting of arid forests, thorny scrublands, wetlands, and seasonal rivers and streams. They are primarily found in low, flat, thorn scrub habitat, but also may be found in dry forests. They are often found at elevations ranging from 400 to 800 m throughout the Chaco. (Dunnum, et al., 2010; Mares and Ojeda, 1981; Mares, et al., 1989; Rosati and Bucher, 1995)

These rodents are relatively large compared to other caviids and resemble rabbits due to their long, thin legs, moderately large, broad, pointed ears, and long, stout vibrissae. They weigh 1.8 to 2.3 kg and range from 420 to 485 mm in head-body length, with their tail adding an additional 19 to 30 mm. They also have large hind feet that measure 91 to 30 mm, and they have nails rather than claws at the end of each digit. The ears range from 58 to 64 mm in length. (Mares, et al., 1989; Redford and Eisenberg, 1992)

The pelage of Chacoan maras is short and smooth, with brownish gray to darker gray fur on their backs that is lightly speckled. Their sides are typically lighter in color, ranging from dark gray to white, and the neck and abdomen are also white. White patches can also be found on their foreheads and behind their eyes. Juveniles differ slightly in color than adults, in that they may have reddish-yellow coloration mixed in with the gray on their backs. Additionally, juveniles lack a third color on their flanks, as found on the adults. (Loder, 1906; Mares, et al., 1989; Neris, et al., 2007; Redford and Eisenberg, 1992)

Little is known about the mating behavior of this species. Apart from activities related to reproduction, female and male Chacoan maras have little to no contact with one another. Even during estrus, females have been observed resisting or withdrawing from males. (Kleiman, 1974)

Little information is available on the reproductive cycle of this species. Gestation lasts 2 months (77 days in captivity) and females bear 2 to 5 young per litter, with an average of 1.5 young per litter. Pups weigh approximately 199 g at birth. (Dunnum, et al., 2010; Kleiman, 1974; Mares and Ojeda, 1981; Redford and Eisenberg, 1992)

Parturition is thought to occur in secluded areas throughout their range, such as under a thorn bush. Newborn Chacoan maras are precocial and can run a few hours after birth. Pups begin following adults a few days after parturition. In order to quickly acquire their natal groups scent, pups often roll around at the group’s urination site shortly after birth. Weaning begins around four weeks old. (Kleiman, 1974)

Little physical contact has been observed between adult and juvenile Chacoan maras. For example, females nurse their young in a sitting posture for bouts lasting an average of five minutes. Nursing occurs in open, exposed areas. Males generally do not participate in parental care, however, they do seem to tolerate young, which is evidenced through their resting and occasionally playing with juveniles. Scanet marking and play help integrate juveniles into the social unit. (Kleiman, 1974)

Little information is available regarding the lifespan or longevity of Chacoan maras.

Chacoan maras are diurnal and are easily observed early in the morning or evening. They are cursorial rodents, which inhabit either burrows dug by themselves or those abandoned by vizcachas. Chacoan maras live either in small family groups or in pairs. Those living in family groups have been observed sitting in star or fan-shaped formations with their rumps in contact or alongside one another while facing in opposite directions. Because Chacoan maras live in an open, savanna habitat, this behavior likely helps them to quickly spot approaching predators. (Kleiman, 1974; Mares, et al., 1989)

Chacoan maras exhibit unique, playful, locomotor-rotational behavior, which has been described as “frisky hops.” This display, which combines several behaviors, includes "vertical leaps, body twisting, head tossing, racing and pivoting, and prancing with kicking back of the hind feet," and predominates juvenile play. Adult males often join juveniles and infants in frisky hop play; however, the mother only does so occasionally. Frisky hop play is often combined with sandbathing (rolling), urine marking, and sniffing the odors of other Chacoan maras. Smell may play an important role in inducing frisky hop play. For example, Chacoan maras have centralized urination sites, which also serve as sandbathing sites. Prior to sandbathing, however, individuals often perform anogenital drags while urinating. Play at these sites is also common and includes head tossing, leaping vertically into the air and racing to and from the site. (Kleiman, 1974)

The home range of Dolichotis salinicola varies between 3.33 to 19.75 km^2, with the average homerange measuring 9.79 km^2. (Dunnum, et al., 2010)

Communication through scent is very important for this species. In captivity, Chacoan maras have been observed to saturate a site with their urine and anal gland secretions. Those sites then become their preferred locations for sandbathing as they provide all members of the group with the same scent. Individuals also urinate on one another as an additional way to share their scent. In addition to scent markings, Chacoan maras make a variety of vocalizations, many of which are very similar to those made by Patagonian maras. For example, young produce a “wheet” call when following and a “whine” when threatening conspecifics. When approached by conspecific rival, Chacoan maras may emit a prolonged wheet that generally drops to a low intensity grunt. (Eisenberg, 1974; Kleiman, 1974)

Chacoan maras primarily forage on leaves and forbs, but also consume woody plants, grasses, fruits, seeds, and succulent species such as cacti and bromeliads. They most often forage on forbs and grasses during the rainy season, with cacti and bromeliads making up a majority of their diet during the dry season. (Mares and Ojeda, 1981; Rosati and Bucher, 1992)

Major predators of Dolichotis salinicola include jaguars, pumas, and Pampas foxes. The coloration of their pelage helps camouflage them from predators and they often try evade predators by outrunning them. Young are born under the protection of dense vegetation and can run a high speeds a few hours after birth. (Taber, et al., 1997; Varela, et al., 2008)

As common herbivores in the eastern Salta province, Chacoan maras are sometimes found in high densities and may have a significant impact on the local environment. Potential impacts may include overgrazing and the destruction of seedlings, which together prevent the forest regeneration. As herbivores, however, they may also be important seed dispersers. Chacoan maras are an important prey species for a number of medium to large bodied predators. Although limited information is available on parasites specific to Chacoan maras, they are known to host the tick species Amblyomma pseudoparvum. (Mares, et al., 1989; Rosati and Bucher, 1995; Taber, et al., 1997; Varela, et al., 2008)

Chacoan maras are popular game animals throughout their geographic range. Indigenous hunters exploit them for food and for their pelts. The pelts of Patagonian maras, a close relative to Chacoan maras, have been made into bedspreads and rugs and sold in stores specializing in regional goods. (Mares, et al., 1989; Ojeda and Mares, 1981)

There are no known adverse effects of Chacoan maras on humans.

According to the IUCN Red List of Threatened Species, Dolichotis salinicola is a species of least concern with no known major threats. This status is based on the species’ wide distribution, presumed large population, and because it is unlikely to be declining at a fast rate. Dolichotis salinicola is found in protected areas within Argentina, Bolivia and Paraguay. (Dunnum, et al., 2010; Wilson and Reeder, 2005)

Dolichotis salinicola was formerly included in the genus Pediolagus as Pediolagus salinicola. A number of common names have been used to refer to this species, including Chacoan mara, dwarf mara, dwarf Patagonian cavy, dwarf Patagonian hare, and salt-desert cavy. In Spanish, it is called conejo del palo, which roughly translates to shrub rabbit. ("The cavies", 1975; Dunnum, et al., 2010; Weir, 1974)