Galictis cuja
lesser grison

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)

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)

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)

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)

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)

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

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)

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

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)

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)

The predators of these animals have not been reported.

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)

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)

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

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.