Galictis cujalesser grison

Geographic Range

Galictis cuja is found across central and southern South America. It has been encountered from southern Peru, throughout Paraguay, and from central Chile extending south to Argentina's Chubut Province. (Redford and Eisenberg, 1992)

Habitat

Lesser grisons occupy a wide range of habitats, and can be found in the extremes of the arid Chaco while also inhabiting environments with extensive vegetation cover in conjuction with open water. Other habitat types include deciduous and evergreen forests, savananas and mountainous regions. Elevations above 4000 meters are not occupied. (Redford and Eisenberg, 1992)

Lesser grisons often frequent rock pilings, hollow trees, and borrows of other animals in search of food or refuge. (Mares, et al., 1989)

  • Range elevation
    0 to 4000 m
    0.00 to 13123.36 ft

Physical Description

Like most other mustelids, G. cuja has a long body with stout legs. It is similar in apearance to its larger cousin G. vittata which inhabits northern latitudes and lower altitudes. In comparison to the genus Mustela, G. cuja is more robust and heavier bodied. (Nowak, 1999)

Galictis cuja is characterized by black coloration begining from the rostrum and extending below the ears and into the chest and underbelly. The diagnostic white "headband" sweeps across the forehead, terminating around the shoulder region. Dorsal coloration is grizzled with yellowish undertones. Color variation and patterning may vary among individuals throughout the geographic range of the species. (Redford and Eisenberg, 1992)

The head and body length of this species is reportedly between 280 and 508 mm, with the tail adding an additional 120 to 193 mm to the total length. These animals weigh between 1 and 2.5 kg. (Nowak, 1999)

Sexual dimorphism is evident among many smaller mustelid species. Larger males maximize their ability to take larger prey, thereby limiting competion with females. Polygyny is correlated with such size dimorphism. Along with large size comes increased breeding fitness and superior fighting ability in competition among other males for females. Sexual dimorphism is suggested in G. cuja, but has not been substantiated. (Nowak, 1999)

Dental Formula: 3/3,1/1,3/4,1/1=34 (Mares, et al., 1989)

  • Sexual Dimorphism
  • male larger
  • Range mass
    1 to 2.5 kg
    2.20 to 5.51 lb
  • Range length
    280 to 508 mm
    11.02 to 20.00 in

Reproduction

While mating habits of G. cuja are not documented, many male mustelids are polygynous. Females can be brought to ovulate only by freguent and rigorous copulation. Delayed implantation is also evident in more thatn 16 mustelid species but has not been recorded in G. cuja. (King and Macdonald, 1999)

Gestation in G. cuja is complete after about 40 days, when 2 to 4 offspring are produced. Young are born in March, August, October and September. (Nowak, 1999)

  • Breeding interval
    The breeding interval of these animals is not reported.
  • Breeding season
    The breeding season of these animals in the wild is not reported.
  • Range number of offspring
    2 to 4
  • Range gestation period
    39 to 40 days

The parental behavor of this species has not been reported. As in all mammals, the female provides her young with food and protection. Most mustelids are altricial, and it is likely that lesser grison are similar. The young are probably born in a burrow or den of some sort, although this has not been documented. The role of males in parental care has not been established. (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

Lifespan/Longevity

Greater grisons (G. vittata) have lived more than 10 years in captivity. Longevity in lesser grisons is unknown. (Nowak, 1999)

  • Average lifespan
    Status: captivity
    10.2 years
    AnAge

Behavior

Grisons are some of the more social of mustelid species. Although they are solitary hunters, they have been observed in groups of 2 or more. In a captive setting, grisons have been kept in groups or pairs in a single enclosure. Wild grisons have also been seen moving together in groups comprising of an adult female and young. Evidence of social hiearchy has not been substantiated. (King and Macdonald, 1999)

Galictis cuja is active during both daylight and nighttime. (Mares, et al., 1989)

Members of this genus are reported to be easily tamed if captured young. They are said to make interesting pets. (Nowak, 1999)

Home Range

The size of the home range of these animals has not been reported.

Communication and Perception

Galictis cuja utilizes a range of vocalizations which include a sharp, growling bark when threatened. It is likely that these vocalizations are also used for communication within the species. As with other mammals, tactile communiction plays an important role between mates, rival, and between mothers and their offspring. Because these animals are active during the day and are social, they probably use some visual signals, such as body posture, to communicate intentions to conspecific. Scent cues are usually important in Mustelids, which have well developed anal scent glands. (Nowak, 1999)

Food Habits

The diet of G. cuja consists of small mammals, birds, eggs, cold-blooded vertebrates, and invertebrates as well as fruit. The stomach contents of one speciemen collected in Peru contained mice and a lizard. (Nowak, 1999; Redford and Eisenberg, 1992)

Athough percieved to be a generalist, studies have shown that the consumtion of introduced European rabbits (Oryctolagus cuniculus) is high among populations of G. cuja where rabbit populations are high. (Duik-Wasser and Cassini, 1998)

We may assume that these animals are capable of hunting chincillas, as they are sometimes kept in captivity for this purpose. (Nowak, 1999)

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
  • Animal Foods
  • birds
  • mammals
  • amphibians
  • reptiles
  • eggs
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • fruit

Predation

The predators of these animals have not been reported.

Ecosystem Roles

Lesser grisons feed on a variety of small mammals and other vertebrates. They therefore have a negative impact on populations of their prey species. (Duik-Wasser and Cassini, 1998; Redford and Eisenberg, 1992)

Economic Importance for Humans: Positive

A study of functional response among lesser grisons toward high populations of exotic European rabbits in Patagonia may confirm G. cuja as effective rabbit control. Young grison are also tamed easily and have been used in the past to capture chinchillas. (Mares, et al., 1989; Nowak, 1999)

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

There are no reported negative effects of this species on humans.

Conservation Status

Lesser grisons are listed by CITES as Appendix III. They have no special conservation status with IUCN Redlist or with the US Department of Fish and Wildlife.

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Robert Melrose (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

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.

carnivore

an animal that mainly eats meat

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

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.

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

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).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

solitary

lives alone

tactile

uses touch to communicate

temperate

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).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

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.

savanna

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.

temperate grassland

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.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Duik-Wasser, M., M. Cassini. 1998. A study on the diet of minor grisons and a preliminary analysis of their role in the control of rabbits in Patagonia. Studies on Neotropical Fauna and the Environment, 33(1): 3-6.

King, C., D. Macdonald. 1999. Weasels and Polecats. Pp. 110-115 in The Encyclopedia of Mammals. Oxford: Andromeda.

Mares, M., R. Ojeda, R. Barquez. 1989. Guide to the Mammals of Salta Province, Argentina. Norman, OK: University of Oklahoma Press.

Mella, J., J. Simonetti, L. Ebensperger. 1991. Trophic-Niche relationships among Galictis cuja, Dusicyon culpaeus, and Tyto alba in central Chile. Journal of Mammalogy, 72: 820-823.

Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition. Baltimore and London: The Johns Hopkins University Press.

Redford, K., J. Eisenberg. 1992. Mammals of the Neotropics. Chicago, Illinois: University of Chicago Press.