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Lesser Grison

Galictis cuja

French: Petit Grison / German: Kleingrison / Spanish: Grison chico

Taxonomy. Mustela cuja Molina, 1782,

Chile.

Four subspecies are recognized.

Subspecies and Distribution.

G. c. cuja Molina, 1782 — W Argentina and Chile.

G. c. furax Thomas, 1907 — NE Argentina, C & E Brazil, Paraguay, and Uruguay.

G. c. huronax Thomas, 1921 — C and S Argentina.

G. c. luteola Thomas, 1907 — W Bolivia and SE Peru.

Descriptive notes. Head-body 28-508 cm, tail 12-19.3 cm; weight 1.2-5 kg. The Lesser Grison has a long body and short limbs. The pelage is yellowish-gray to brown; the face, throat, upper chest, and limbs are black. A white stripe extends across the forehead and down the sides of the neck, separating the black of the face from the gray or brown of the back. The claws are strong and curved. Dental formula: I 3/3, C 1/1, P3/3,M1/2=234

Habitat. Lesser Grisons are found in a wide variety of habitats, from sea level to 4200 m, including seashore, arid scrub, chaco desert, Gran Chaco, Chiquitano woodland, open thorn woodland, cerrado, caatinga, savannah, steppes, evergreen shrublands, semideciduous lower montane forest, brushy areas below the timberline, Tucuman-Bolivian woodlands, wet forest, Brazilian Atlantic forest, high Andean shrublands, Polylepis woodlands, puna grasslands, marshes, high elevation wet meadows “bofedales”, Equisetum-dominated scrub, overgrazed pastures, and agricultural areas of the Pampas. Most localities in Bolivia are between 2000 and 4200 m. Lesser Grisons frequently occur near water.

Food and Feeding. The diet includes small mammals (especially rodents and lagomorphs), birds, eggs, amphibians, reptiles, invertebrates, and fruit. In central Chile, the diet was found to consist of 352% rodents, 26-5% introduced European Rabbits (Oryctolagus cuniculus), 20-7% unidentified mammals, 14-7% reptiles (Liolaemus chiliensis and Philodryas chamissonis), and 2-9% unidentified passeriform birds. Average prey weight was 350 g. In Patagonia, Argentina, the diet is 46-:3% rodents, 18-9% lagomorphs, 17-9% lizards, and 16-8% birds; as lagomorph density increases,its percentage in the diet increases up to 96-8%. In coastal south-eastern Argentine, mammals, including rodents (79-1%, at least eight species) and European Hare Lepus europaeus (20-9%), are the main prey items year-round; birds (7-8%) and invertebrates (5-2%) are also eaten. Lesser Grisons frequently prey on guinea pigs and are capable of running down and killing Dwarf Cavies (Microcavia australis).

Activity patterns. Active mainly during the day, with occasional activity at night. Rest sites are in hollow trees, crevices, boulder piles, burrows of other animals, at the base of Polylepis trees, amongst tree roots and rocks, or in banks adjacent to wet meadows at high elevations. Four or five individuals may occupy a burrow system, which may reach 4 m in depth. One burrow system occupied by five individuals in Chile was on a slope among rocks and roots of a Guevina avellana tree in Nothofagus obliqua woods; leaves of Greiga obscured the entrances.

Movements, Home range and Social organization. Mostly solitary, although pairs or small groups are occasionally seen.

Breeding. Gestation is around 39 days. Litter size is two to five. Offspring have been observed in March, August, September, and October.

Status and Conservation. Classified as Least Concern in The IUCN Red List. Lesser Grisons are generally considered not to be threatened, butfield studies are needed to learn more about their natural history, ecology, and conservation status.

Bibliography. Wozencraft (2005), Yensen & Tarifa (2003b), Zapata et al. (2005).