Dolichotis patagonum

Geographic Range

Dolichotis patagonum is endemic to the open grasslands and shrubland steppes of Argentina, and is distributed between 28°S and 50°S.

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Patagonian maras live only in the arid central and southern regions of Argentina. Generally classified as desert, this area exhibits a wide range of distinct microhabitats ranging from sandy plains to thorny shrubland steppes. Rainfall is extremely unpredictable and there are huge shifts in precipitation and floral composition between wet and dry seasons. The area is quite warm, with average temperatures in the summer usually around 20 degrees Celsius and winter temperatures rarely dropping below freezing. Generally, Patagonian maras prefer to build dens in open habitat dominated by grasses and other low-growing plants. Though it dens in areas that are densely vegetated, they visually monitor for predators, which is less effective in more closed habitats. Large settlements of Patagonian maras have been observed on and around sheep ranches, most likely due to their similar habitat preferences.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• savanna or grassland savanna or grassland
• scrub forest scrub forest

• Other Habitat Features
• agricultural agricultural

Physical Description

Dolichotis patagonum is the second largest member of the family Caviidae . One study reported average weights of males and females as 7.73 kg and 8.44 kg, respectively. However, most accounts report that males are larger than females. Length ranges from 610 to 810 mm with an average of 700 mm. They can be distinguished from other members of Caviidae by their large size, long rabbit-like ears (Dolichotis literally means "long ear"), and short, nearly hairless tail which it holds close to the body. Unlike other cavies, which have anal glands anterior to the anus, the anal glands of D. patagonum are located between the anus and the base of the tail. It has short, grizzly gray fur , with a large, conspicuous patch of white on the rump. Midway up the rump a sharply contrasting area of black occurs, which quickly fades to gray. The venter is white, with patches of rusty orange fur on the chin, cheeks, and flanks. Two subspecies are recognized: Dolichotis patagonum centricola and Dolichotis patagonum patagonum , which are distinguished based on geographic location and fur coloration.

Much like ungulates, Dolichotis patagonum has elongated metapodials in its hindlegs as a modification for fast and efficient running . Forelegs are significantly longer than in most other rodents , and both the hind- and forefeet are small with hoof-like claws. Forefeet have four digits while hindfeet have three, and all digits have a claw. The elbow lies relatively high on the forelimb as the radius is longer than the humerus. Dolichotis patagonum has a dental formula of 1/1, 0/0, 1/1, 3/3, and cheek teeth are hypsodont and evergrowing.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

Dolichotis patagonum is strongly monogamous, and male-female pairs usually bond for life. The pair-bond is maintained mainly by the efforts of the male, who follows and guards the female wherever she goes. To mark her as his territory, he urinates on her, spreads anal gland secretions around her and fiercely defends her from rival males. Males have been observed fighting, but there has never been a documented case of mate stealing. Male typically defend a 20 m^2 mobile territory centered around his female. Because estrus occurs once every 3 to 4 months and lasts for just half an hour, monogamy is advantageous, as spending all his time with one female assures a male that he does not miss his chance to breed. Monogamy may have also arisen as a response to the patchy and sparsely distributed food resources of the region. Since this sort of resource distribution is likely to result in a very scattered distribution of females, a male has the highest chance of successful breeding by finding one female and remaining with her. Another benefit to pair-bonds is that females are able to invest additional time and attention to caring for her young, relying on the male to watch for predators. Monogamy increases the males reproductive success both by lowering the death rate of his own offspring and increasing the longevity of his mate, allowing him more chances to breed.

• Mating System
• monogamous monogamous

Female Patagonian maras are sexually mature by 8 months of age. Estrus occurs once every 3 or 4 months and lasts only about half an hour. This extremely short estrous cycle is very unusual and most likely played a part in the evolution of monogamy in this species. Females in captivity often conceive shortly after parturition and can give birth to 3 or 4 litters per year, however, in the wild only one litter per year is produced. Litters range in size from 1 to 3 pups, with average litters containing 2. Rarely, a few females may have a second litter around January, but the majority of pups are born between mid August and late December. There is a large pulse of births between mid September and late October, with almost two thirds of pups being born during this time period. Gestation lasts an average of 100 days in the wild.

Females have 6 or 8 teats and nurse 1 or 2 pups at a time. On rare occasions females have been seen nursing up to 4 pups, suggesting occasional milk stealing by unrelated pups. It is thought that females recognize their young mainly by size, so pups of similar size to a female's own pups may have greater milk stealing success. Females also recognize their young by sound and scent cues. Occasionally, orphaned pups may be "adopted" by another female and allowed to suckle. However, females usually aggressively reject interloping pups by lunging, chasing, biting and shaking, or throwing them away from her. Some pups make frequent attempts to steal milk and many have tattered and damaged ears from these fierce rejections. Nursing bouts last for about half an hour and adult visits to the den usually last about an hour. Pups are usually nursed for about 75 to 78 days, which is unusually long compared to other rodents.

Like many ungulates, Dolichotis patagonum exhibits the "hider" strategy through the first part of their lives, staying close to the burrow and hiding at the signal from an adult sentry. As pups mature, they go through a "follower" phase where they trail behind their parents on foraging expeditions farther away from the burrow. Most young disperse at the time of weaning, however some stay with their parents until the next breeding season.

Though members of this species spend most of the year associating strictly as male-female pairs, when pups are born Dolichotis patagonum gathers in large groups around large warren "settlements" and raise young in communal creches. Each communal den has on average 4.26 breeding adults and 4.46 pups; however, up to 29 pairs have been observed sharing a single den. Since males aggressively guard their mates, only one pair at a time is present at the den.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

Males contribute very little in terms of direct parental care. They rarely interact with small pups, and interactions with large pups is limited to sitting or foraging nearby. However, males spend the majority of their time watching for predators, which significantly lowers predation risk faced by his offspring and mate.

• Parental Investment
• male parental care male parental care
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • male
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • male
• pre-independence
  • provisioning
    • female
  • protecting
    • male

Lifespan/Longevity

Little information could be found on the lifespan of wild or captive mara.

Behavior

Patagonian maras are diurnal, cursorial rodents. For most of the year, they travel in male-female bonded pairs, and very rarely are there more than three maras spotted together at one time. Male-female pairs travel during the day, spending more time grazing in rich patches than sparse ones. Patagonian maras form large groups called settlements, which consists of a collection of dens or warrens. Some warrens are small and widely spaced and used by just a single pair, while some large dens can be shared by up to 29 pairs. Local population densities may rise dramatically during this time, and groups of up to 70 maras have been observed. Females spend much more time with offspring than males, and males spend much more time watching for predators than females. Due to the large physiological investment that females make in reproduction, females spend more time feeding than males during this time as well. Males fiercely defend their mates. As a result, typically only one pair at a time can occupy the den. Breeding pairs "take turns" visiting the den for approximately one hour at a time to nurse their young.

• Key Behaviors
• cursorial
• terricolous
• diurnal diurnal
• motile motile
• nomadic nomadic
• solitary solitary
• territorial territorial

Home Range

The home range of Patagonian maras drifts continuously, most likely as a result of the patchily distributed and widely spaced food resources present in the region. They eat only the very tips of grass blades, so food resources are exhausted very quickly. Once a resource patch has been exhausted, it takes up to four months to be completely renewed. A single, static territory large enough to support a pair of maras for a year would likely be too large for a pair of maras to defend against inter- and intraspecific competitors. Furthermore, communal denning would be nearly impossible, as it is unlikely that ranges of sufficient size would overlap around a communal warren. Therefore, small, drifting ranges are favorable, allowing Patagonian maras to be near the communal warren during pupping season while also freeing it from the demanding task of defending large territories. Their home ranges are between 33.25 and 197.5 ha, with an average of 97.87 ha. They intensively forage within a 1 ha range each day, and their home range drifts continuously at a rate of about 11 ha/day outside of the breeding season.

Communication and Perception

Dolichotis patagonum prefers open habitats. Similar to ungulates, D. patagonum relies on early detection of predators to allow adequate time for escape. Also similar to some ungulates, Patagonian maras exhibit stotting behavior, which is characterized by a bounding gait that advertises strength and speed and discourages a long and costly chase by the predator.

Like many rodents, Dolichotis patagonum has a pair of anal scent glands. Males are frequently observed anal dragging, which results in a unique looking scent mark. Anal gland secretions play a major role in the mobile territory that males form around their mate. It is not know whether D. patagonum uses auditory signals to communicate with conspecifics.

• Communication Channels
• visual visual
• chemical chemical

• Other Communication Modes
• pheromones pheromones
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

The range of Dolichotis patagonum encompasses a variety of habitats from desert to shrubland steppe. A strict herbivore, D. patagonum shows considerable flexibility in adjusting its diet to different ecosystems. For example, at the southern edge of its range in Sierra las Quijadas National Park north of San Luis, Argentina, D. patagonum experiences considerable variation in rainfall throughout the year and the local environment undergoes considerable changes in respect to floral composition between wet and dry seasons. Regardless of season, however, grasses make up nearly 70% of D. patagonum 's diet. Despite the fact that most plant biomass in the region consists of forbs and shrubs, D. patagonum selects relatively rare grasses as its primary forage. Most grasses consumed are in the genus Pappophorum . In total, D. patagonum forages on 24 species of grasses and 22 other species of plants. In addition to grass, a significant portion (11%) of D. patagonum 's diet consists of various species of cacti. Generally, cacti is about 75% water by weight and could represent a significant source of water to this species. This may help offset the unpredictability of rainfall throughout the range of D. patagonum >.

Near the central part of its range, evidence suggests that the grass genera Poa and Panicum make up the bulk of Dolichotis patagonum 's diet, followed by Stipa and Bromus . Open-shrubland inhabitants also forage on Doli chotis patagonum and grassland inhabitants consume Lycium . Dolichotis patagonum in sandy grasslands and lithosol shrublands prefer Prosopis . These habitat specific differences display the dietary flexibility of this herbivore. During droughts, Dolichotis patagonum adjusts its diet to include more moisture-rich plants.

Patagonian maras are hindgut fermenters. Their diet is very high in fiber and cellulose, which is broken down by bacterial fermentation in a pouch called the cecum attached to the large intestine. They produce a special feces, which is ingested and re-digested. Wild Patagonian maras have been observed near sheep ranches consuming sheep dung.

• Primary Diet
• herbivore herbivore
  • folivore folivore
• coprophage coprophage

• Plant Foods
• leaves
• seeds, grains, and nuts
• fruit
• flowers

• Other Foods
• dung

Predation

Dolichotis patagonum has evolved a predator response system very similar to that of ungulates. It relies on its well-developed senses of hearing, vision and smell for early predator detection in open habitats. In the the event of a chase, D. patagonum is able to run very fast (up to 45 mph). This species exhibits stotting behavior identical to that seen in some ungulates. Its brown coloration helps camouflage it from potential predators. The main predators of the mara are Suran's foxes , South American grey foxes and pumas ; however, due to human activities populations of both of these species have declined sharply. Humans now present the main threat to D. patagonum , both through habitat alteration and poaching. Other predators include lesser grison and variable hawks .

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Patagonian maras are herbivores and affect their environment by grazing on plants. They also eat fruit and distribute seeds through their feces. Patagonian mara pups form an important prey base for many species of birds , canids , and felids . They are also host a number of parasitic roundworms , including Wellcomia dolichotis , Trichostrongylus retortaeformis , and Graphidioides affinis .

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Patagonian maras breed easily in captivity and make excellent zoo specimens. They can live with other representative species of the region and make for an exciting walk-through exhibit. They are very charismatic and are used as an ambassador species to educate the general public about the rapidly declining Pampas, a large area of South American lowlands. Patagonian maras can be kept as pets and can be trained to walk on a leash. They are hunted for their skins, which are used to make bedspreads and rugs in Argentina, and their meat.

• Positive Impacts
• pet trade pet trade
• food food
• ecotourism ecotourism

Economic Importance for Humans: Negative

There are no known adverse effects of Dolichotis patagonum on humans.

Conservation Status

Dolichotis patagonum is classified as near threatened on the IUCN's Red List of Threatened Species. Habitat change, most likely caused by the introduction of domestic sheep , is a major problem facing this species. Overgrazing by sheep causes a shift from large grassy patches to a landscape characterized by smaller patches of woody plants. Reproductive success of D. patagonum populations in open grassland habitats tends to be greater than those in closed habitats. Dolichotis patagonum are also vulnerable to hunting, as it is killed for its meat and skin. Adults are killed with guns or wire snares, while pups are captured in nets placed over the entrances of burrows. Lepus europaeus (European hares), which is not native to South American, has introduced Jonhe' disease and toxoplasmosis to D. patagonum . In many areas, competition with L. europaeus is so intense that D. patagonum has been become locally extinct.

Additional Links

Encyclopedia of Life

Contributors

Molly Mascow (author), University of Michigan-Ann Arbor, Phil Myers (editor), University of Michigan-Ann Arbor, John Berini (editor), Animal Diversity Web Staff.

References

Baldi, R. 2007. Breeding success of the endemic mara Dolichotis patagonum in relation to habitat selection: conservation implications. Journal of Arid Environments , 68: 9-19. Accessed April 04, 2011 at http://www.sciencedirect.com.proxy.lib.umich.edu/science?_ob=MiamiImageURL&_imagekey=B6WH9-4JTR95P-6-1&_cdi=6845&_user=99318&_pii=S0140196306001212&_check=y&_origin=gateway&_coverDate=01/31/2007&view=c&wchp=dGLzVtz-zSkWA&md5=1e3c0f66ca0792035b80550ffdd64d82&ie=/sdarticle.pdf .

Campos, C., M. Tognelli, R. Ojeda. 2001. Dolichotis patagonum. Mammalian Species , 652: 1-5. Accessed March 15, 2011 at http://www.jstor.org.proxy.lib.umich.edu/stable/3504392 .

Chillo, V., D. Rodriguez, R. Ojeda. 2010. Niche partitioning and coexistence between two mammalian herbivores in the Dry Chaco of Argentina. Acta Oecologica , 36/6: 611-616.

Heise, T., S. Stempell, R. Wanker. 2006. Mate guarding in the mara, Dolichotis patagonum (Zimmermann, 1780), at Tierpark Hagenbeck. Zoologische Garten , 75/5-6: 345-350.

Kufner, M. 1995. Temporal activity of the mara (Dolichotis patagonum) in the Monte desert, Argentina. Studies on Neotropical Fauna and Environment , 30/1: 37-43.

Puig, S., M. Cona, F. Videla, E. Mendez. 2010. Diet of the mara (Dolichotis patagonum), food availability and effects of an extended drought in Northern Patagonia (Mendoza, Argentina). Mammalian Biology , 75/5: 389-398.

Rodriguez, D., M. Ana Dacar. 2008. Diet composition of the mara (Dolichotis patagonum) in the southeast of the Monte desert of La Pampa province, Argentina.. Mastozoologia Neotropical , 15/2: 215-220.

Sombra, M., A. Mangione. 2005. Obsessed with grasses? The case of mara Dolichotis patagonum (Caviidae : Rodentia). Revista Chilena de Historia Natural , 78/3: 401-408.

Taber, A., D. Macdonald. 1992. Communal breeding in the mara, Dolichotis patagonum. Journal of Zoology , 227/3: 439-452.

Taber, A., D. Macdonald. 1992. Spatial organization and monogamy in the mara Dolichotis-patagonum. Journal of Zoology (London) , 227/3: 417-438.

2011. "Patagonian Mara (Dolichotis patagonum)" (On-line). World Association of Zoos and Aquariums. Accessed April 07, 2011 at http://www.waza.org/en/zoo/visit-the-zoo/rodents-and-hares/dolichotis-patagonum .