Grisons

Grisons, also known as South American wolverines, are any mustelids within the genus Galictis. They are found throughout South America, Central America and southern Mexico. Grisons are said to have appeared in South America during the early Pleistocene approximately 2.5 million years ago. They may be descended from the fossil genera Trigonictis and Sminthosinus, which lived in North America during the mid to late Pliocene.(1) There are at least three known fossil species, all of which were found in Argentina.(2)

Grisons are members of the subfamily Ictonychinae, which also includes the African striped weasel, Patagonian weasel, marbled polecat, striped polecat and Saharan striped polecat.(3)(4)

References

  1. Yensen, Eric, and Teresa Tarifa. “Galictis vittataMammalian Species 2003.728 (2003): 727: pp. 1-8.
  2. Yensen, Eric, and Teresa Tarifa. “Galictis cujaMammalian Species 2003.727 (2003): Number 728: pp. 1–8.
  3. Nascimento, Fabio Oliveira do. “On the correct name for some subfamilies of Mustelidae (Mammalia, Carnivora).” Papéis Avulsos de Zoologia 54.21 (2014): 307-313.
  4. Law, Chris J., Graham J. Slater, and Rita S. Mehta. “Lineage diversity and size disparity in Musteloidea: testing patterns of adaptive radiation using molecular and fossil-based methods.” Systematic biology 67.1 (2018): 127-144.

(1) Greater Grison (Galictis vittata)

Photo by Tony Hisgett

The greater grison has a range from the coast of eastern Mexico, to as far south as the northern half of South America.

Appearance

The greater grison has a small, flat head with whitish rounded ears. The bottom half of the head right below the eyes is black, while the dorsum is grey with white or grey-tipped dorsal guard hairs, and is separated from the black or grizzled under-parts on the rest of its body by a light-colored, half-inch wide stripe. This stripe runs across their forehead and down the sides of either shoulder. Their tails have bushy fur that is similar in colour to that of their backs. The dorsum fur is reported to be fairly coarse, while the darker undercoat is much smoother. They have five webbed toes. (1)

Habitat

Greater grisons are typically seen near rivers, streams, wetlands, and a wide range of forest cerrado habitats. They tend to be found in elevations below 500 metres (1,600 ft). In some regions, they’ve been observed in cultivated areas such as plantations, cane fields, and rice paddies.(2)

Behaviour

They are most active during the day, and spend their nights in vacated burrows of other animals.(3) Despite being a terrestrial animal, the greater grison is both an excellent climber of trees and swimmer; the latter being assisted by their webbed toes.(1) If raised in captivity from a young age, greater grisons have been reported to make affectionate pets. In some cases, they are also kept for the purpose of controlling rodent populations. Both wild and captive greater grisons have been described as playful and inquisitive.(4)

Reproduction

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Diet

Greater grisons will hunt alone or in pairs, and feed on birds, small mammals, and fruits and vegetables. In captivity, is has been observed that greater grisons hold food items with their forepaws, but they do not appear to use their forepaws to manipulate food items.(2)

Natural predators

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Range map

Body length: 45–60 cm / 18–24 in (males), 50 cm / 20 in (females)
Tail length: 14–20 cm / 5.5–7.9 in (males)
Weight: 1.5–3.8 kg / 3.3–8.4 lb (males), 1.8 kg / 4 lb (females)
Lifespan: Unknown (wild), up to 10 years (captivity)
Range: The coast of eastern Mexico, northern half of South America.
Conservation status: Least concern
Recognised subspecies(5)

  1. G. v. andina
  2. G. v. brasiliensis
  3. G. v. canaster
  4. G. v. vittata
References

  1. Yensen, Eric, and Teresa Tarifa. “Galictis vittata.” Mammalian Species 2003.727 (2003): 1-8.
  2. Gregg, M. 2013. “Galictis vittata” (On-line), Animal Diversity Web. Accessed May 20, 2020
  3. Wilson, Don E., and Russell A. Mittermeier. Handbook of the Mammals of the World. No. C/599.012 H3. 2009.
  4. Leopold, A. 1972. Wildlife of Mexico. Berkeley and Los Angeles, California: University of California Press.
  5. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Galictis vittata in Mammal Species of the World. – A Taxonomic and Geographic Reference.

(2) Lesser Grison (Galictis cuja)

Photo by Ken Erickson

The lesser grison is found across central and southern South America.

Appearance

The lesser grison has a black coloration beginning from the nose, extending below the ears and into the chest and underbelly. The dorsal coloration is grizzled grey with yellowish undertones, separated from the black underside by a pale buff-coloured stripe, that runs from the forehead to the shoulders along the lower margin of the grey furred area. They have five webbed toes. Lesser grisons are smaller than greater grisons.(1)

Habitat

They are usually found near water and live in rocks, under tree roots or abandoned burrows.

Behaviour

Lesser grisons can be either solitary, or live in small groups of 2 or more consisting of parents and offspring. They form monogamous mating pairs—hunting together while raising their young. They sleep in hollow trees, natural crevices, or excavated burrows overnight. Some burrows may be as deep as 4 m (13 ft), and have entrances obscured by leaves.(1)

Reproduction

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Diet

Their diet consists of small mammals, amphibians, small reptiles, eggs and fruit. Similar to the greater grison, they can be kept as pets if raised from infancy; at times for the purpose of hunting pests.(1)

Natural predators

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Range map

Body length: 27–52 cm / 11–20 in (males)
Tail length: 14–19 cm / 5.5–7.5 in (males)
Weight: 1.2–2.4 kg / 2.6–5.3 lb (males)
Lifespan: Unknown (wild), up to 10 years (captivity)
Range: Central and southern South America.
Conservation status: Least concern
Recognised subspecies(2)

  1. G. c. cuja
  2. G. c. furax
  3. G. c. huronax
  4. G. c. luteola

References

  1. Yensen, Eric, and Teresa Tarifa. “Galictis cuja.” Mammalian Species 2003.728 (2003): Number 728: pp. 1–8
  2. Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Galictis cuja in Mammal Species of the World. – A Taxonomic and Geographic Reference.

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