Caluromysiops irrupta, Sanborn, 1951

Russell A. Mittermeier & Don E. Wilson, 2015, Didelphidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 129-186 : 133-134

5.

Black-shouldered Opossum

Caluromysiops irrupta

French: Opossum a épaules noires / German: Schwarzschulterbeutelratte / Spanish: Raposa lanuda de hombros negros

Taxonomy. Caluromysiops irrupta Sanborn, 1951 ,

“ Quincemil, Province of Quispicanchis ,” Cuzco, Peru.

This species is monotypic.

Distribution. S Colombia, E Peru, W Brazil, and likely in N Bolivia.

Descriptive notes. Head-body 25-33 cm, tail 31-34 cm; weight ¢.300-500 g. The Black-shouldered Opossum has a unique fur pattern, making it easily recognizable. Its overall body fur is frosted grayishbrown, fading to buffy or whitish on sides and entire head. It lacks any sort of eyerings, which are common in the majority of opossums, or any mid-rostral stripe. Most conspicuous fur features are large black patches that cover forearms from shoulders down to inner forearms and wrists. These patches join along the mid-dorsum and run parallel to each other along back, eventually fading to the overall fur color on rump. Tail length is ¢.120% of head-body length, and tail is almost completely furred, with fur present from tail base to up to 2 cm from tip on dorsal side and proximal one-third ventrally. Ventral fur is buffy and soft, long, and woolly; ears are yellowish. Female Black-shouldered Opossums are reported to have a complete pouch, but number of mammae is currently unknown. Its karyotype is unknown. There is no sexual dimorphism in skull size and shape.

Habitat. Only a few localities in Amazonian lowland mature tropical humid forests below elevations of 700 m.

Food and Feeding. The Black-shouldered Opossum is known from only a few specimens, and most information on any aspect ofits natural history is merely anecdotal. Feeding information is restricted to a few observations of individuals feeding on nectar from flowers of Quararibea cordata (Malvaceae) in Amazonia. Black-shouldered Opossums kept in zoos are reported to eat animals as food.

Breeding. Female Black-shouldered Opossums with young were received from animal dealers in July-August. No more than two young have been noted per female, and a captive female was photographed with two young clinging on her back.

Activity patterns. Black-shouldered Opossums have only been seen in the wild at night, but their specific activity patterns are virtually unknown.

Movements, Home range and Social organization. Black-shouldered Opossums move slowly in the canopy and have been seen hanging by their tails to feed on nectar.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Although Black-shouldered Opossums apparently are locally rare, they have a relatively widespread distribution and have been seen in continuous protected forested areas within in Peru. Some populations of Black-shouldered Opossums are inferred to be declining due to loss of forest habitats, although no real population data exist because it is known from fewer than 30 specimens. There seem to be no major conservation threats as a whole. Distribution of the Black-shouldered Opossum in Peruis considered relatively secure because it occurs within several large protected areas, but its distribution in Brazil is subject to intense habitat loss. Nevertheless, recent sightings of Black-shouldered Opossums suggest some degree of tolerance to habitat degradation.

Bibliography. Astua (2010), Emmons (2007), Emmons & Feer (1997), Gardner (2005), zor & Pine (1987), Janson et al. (1981), da Silveira et al. (2014), Voss & Jansa (2009).

Figures

65. Pygmy Opossum (Chacodelphys formosa), 66. Agricola’s Opossum (Cryptonanus agricola), 67. Chacoan Mouse Opossum (Cryptonanus chacoensis), 68. Guaiba Mouse Opossum (Cryptonanus guahybae), 69. Unduavi Mouse Opossum (Cryptonanus unduaviensis), 70. . Emilie’s. 9 Opossum.. Gracilinanus. (null), 71. Aceramarca Opossum (Gracilinanus aceramarcae), 72. Agile Opossum (Gracilinanus agilis), 73. Wood Sprite Opossum (Gracilinanus dryas), 74. Northern Gracile Opossum (Gracilinanus marica), 75. Brazilian Gracile Opossum (Gracilinanus microtarsus)

Distribution. S Colombia, E Peru, W Brazil, and likely in N Bolivia.