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 (Dunnum, et al., 2010)varies between 3.33 to 19.75 km^2, with the average homerange measuring 9.79 km^2.
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 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)include
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.
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)was formerly included in the genus
Jessica Gorchow (author), University of Michigan-Ann Arbor, Phil Myers (editor), University of Michigan-Ann Arbor, John Berini (editor), Animal Diversity Web Staff.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
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.
uses smells or other chemicals to communicate
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.
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.
parental care is carried out by females
an animal that mainly eats leaves.
A substance that provides both nutrients and energy to a living thing.
An animal that eats mainly plants or parts of plants.
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).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
chemicals released into air or water that are detected by and responded to by other animals of the same species
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
scrub forests develop in areas that experience dry seasons.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
uses touch to communicate
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).
Living on the ground.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
young are relatively well-developed when born
1975. The cavies. Pp. 444-445 in B Grzimek, ed. Grzimek's Animal Life Encyclopedia, Vol. 11, 1 Edition. New York: Van Nostrand Reinhold Company.
Dunnum, J., J. Vargas, N. Bernal, U. Pardinas, R. Ojeda. 2010. "Dolichotis salinicola" (On-line). IUCN Red List of Threatened Species. Accessed April 04, 2011 at http://www.iucnredlist.org/apps/redlist/details/6786/0.
Ebensperger, L., H. Cofre. 2001. On the evolution of group-living in the New World cursorial hystricognath rodents. Behavioral Ecology, 12/2: 227-236. Accessed March 13, 2011 at http://beheco.oxfordjournals.org/content/12/2/227.short.
Eisenberg, J. 1974. The function and motivational basis of hystricomorph vocalizations. Symposia of the Zoological Society of London: The biology of hystricomorph rodents, 34: 211-247.
Guglielmone, A., S. Nava. 2010. Rodents of the subfamily Caviinae (Hystricognathi, Caviidae) as hosts for hard ticks (Acari: Ixodidae). Mastozoología Neotropical, 17/2: 279-286. Accessed May 11, 2011 at http://www.scielo.org.ar/pdf/mznt/v17n2/v17n2a03.pdf.
Honacki, J., K. Kinman, J. Koeppl. 1982. Mammal species of the world : a taxonomic and geographic reference. Lawrence, Kansas: Allen Press, Inc. and The Association of Systematics Collections.
Houchon, D., E. Douzery. 2001. From the Old World to the New World: A molecular chronicle of the phylogeny and biogeography of Hystricognath rodents. Molecular Phylogenetics and Evolution, 20/2: 238=251. Accessed March 13, 2011 at http://www.sciencedirect.com.proxy.lib.umich.edu/science?_ob=ArticleURL&_udi=B6WNH-457VF9K-7&_user=99318&_coverDate=08%2F31%2F2001&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_acct=C000007678&_version=1&_urlVersion=0&_userid=99318&md5=c921a7d485d468a3a6f4c5bd7dc8d04b&searchtype=a.
Kleiman, D. 1974. Patterns of behaviour in hystricomorph rodents. Symposia of the Zoological Society of London: The biology of hystricomorph rodents, 34: 171-209.
Loder, E. 1906. Note on the Cavies of the Genus Dolichotis and on Living Specimens of D. Salinicola. Proceedings of the Zoological Society of London, 76: 96-97, 461-462.
Lord, R. 2007. Mammals of South America. Baltimore: Johns Hopkins University Press.
Luckett, W., J. Hartenberger. 1985. Evolutionary relationships among rodents : a multidisciplinary analysis. New York: Plenum Press.
Mares, M., R. Ojeda. 1981. Patterns of diversity and adaptation in South American hystricognath rodents. Mammalian biology in South America : a symposium held at the Pymatuning Laboratory of Ecology, May 10-14, 6: 393-432.
Mares, M., R. Ojeda, R. Barquez. 1989. Guide to the Mammals of Salta Province, Argentina. Norman: University of Oklahoma Press.
Martin, T. 1994. African origin of caviomorph rodents is indicatd by incisor enamel microstructure. Paleobiology, 20/1: 5-13. Accessed March 13, 2011 at http://www.jstor.org.proxy.lib.umich.edu/stable/2401146.
Neris, N., E. Rivarola, P. Clark. 2007. Fauna silvestre del Paraguay (Wildlife of Paraguay). Asunción, Paraguay: Natura Vita.
Ojeda, R., M. Mares. 1981. Conservation of South American mammals: Argentina as a paradigm. Mammalian biology in South America : a symposium held at the Pymatuning Laboratory of Ecology, May 10-14, 6: 505-521.
Osgood, W. 1944. Nine New South American rodents. Chicago: Field Museum of Natural History.
Redford, K., J. Eisenberg. 1992. Chicago: University of Chicago Press.
Rosati, V., E. Bucher. 1992. Seasonal diet of the Chacoan Cavy (Pediolagus salinicola) in the western Chaco, Argentina. Mammalia, 56/4: 567–574. Accessed April 05, 2011 at http://www.reference-global.com/doi/abs/10.1515/mamm.19220.127.116.117.
Rosati, V., E. Bucher. 1995. Relative Abundance and Diet Composition of Chacoan Cavies in Relation to Range Condition. Journal of Range Management, 48/6: 482-486. Accessed April 05, 2011 at http://www.jstor.org/stable/4003056 ..
Taber, A., A. Novaro, N. Neris, F. Colman. 1997. The food habits of sympatric jaguar and puma in the Paraguayan Chaco. Biotropica, 29/2: 204-213. Accessed March 13, 2011 at http://www.jstor.org/stable/2389036.
Varela, O., A. Cormenzana-Méndez, L. Krapovickas, E. Bucher. 2008. Seasonal Diet of the Pampas Fox (Lycalopex gymnocercus) in the Chaco Dry Woodland, Northwestern Argentina. Journal of Mammalogy, 89/4: 1012-1019. Accessed March 13, 2011 at http://www.bioone.org/doi/full/10.1644/07-MAMM-A-125.1.
Vaughn, T., J. Ryan, N. Czaplewski. 2011. Mammalogy. Sudbury, MA: Jones and Bartlett Publishers, LLC.
Verzi, D., C. Quintana. 2005. The caviomorph rodents from the San Andres Formation, east-central Argentina, and global Late Pliocene climatic change. Palaeogeography, Palaeoclimatology, Palaeoecology, 219: 303-320. Accessed March 13, 2011 at http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6R-4FJV243-1&_user=10&_coverDate=04%2F18%2F2005&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_searchStrId=1676811116&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=98e272639363503dadbbbb31e0634a93&searchtype=a.
Weir, B. 1974. Reproductive characteristics of hystricomorph rodents. Symposia of the Zoological Society of London: The biology of hystricomorph rodents, 34: 265-301.
Wilson, D., D. Reeder. 2005. Mammal species of the world : a taxonomic and geographic reference - 3rd edition. Baltimore: The Johns Hopkins University Press.
Woods, C. 1981. The history and classification of South American hystricognath rodents: Reflections on the far away and long ago. Mammalian biology in South America : a symposium held at the Pymatuning Laboratory of Ecology, May 10-14, 6: 377-392.