Monodelphis americana (Muller, 1776)

Astúa, D., 2015, Didelphidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 129-186 : 153

43.

Northern Three-striped Opossum

Monodelphis americana

French: Opossum a trois raies / German: Dreistreifen-Spitzmausbeutelratte / Spanish: Colicorto estriado

Other common names: Three-striped Short-tailed Opossum

Taxonomy. Sorex americanus P. LL. S. Muller, 1776 ,

“Brasilien.” Restricted by A. Cabrera in 1958 to “Pernambuco” (= Recife), Pernambuco, Brazil.

As understood here, this species includes, as synonyms, M. rubida and M. umbristriata because specimens with the color patterns ofthese two species were recovered nested within M. americana in a recent phylogenetic analysis. M. americana likely includes more than one species, but additional analyses are needed. Monotypic.

Distribution. E Brazil, from E Para to coastal Santa Catarina, and inland W to Brasilia. Also mentioned from NE Argentina (Misiones), but specific identification of these records is questioned.

Descriptive notes. Head—body 9-13.7 cm, tail 4-6 cm; weight 23-46 g. The Northern Three-striped Opossum has tawny-brown dorsal fur, faintly grizzled and slightly reddish on rump, with three distinct black stripes, central one running from nose to tail (although less distinct on face) and lateral ones from shoulder to tail. This color pattern, however, is present in young specimens, young adults of both sexes, and older females, while older males can have a warm red-brown, near-chestnut, dorsal fur, extending on outer side of hindlegs and brighter, almost orange behind ears, without any dorsalstripes or sometimes with three faint dorsalstripes. Head lacks any eye-rings. Tail length is ¢.50% of head-body length, and tail has fur only at its base and is bicolored, blackish dorsally and pale ventrally. Ventral fur is pale creamy yellow to orange-gray, gray-based, extending to chin and throat, but it can be gray, frosted yellow-white throughout in older specimens. Ears are naked and brown. Females lack a pouch and have 15 mammae, with seven on each side and a central mamma. The Northern Three-striped Opossum has a 2n = 18, FN = 22 karyotype, and the X-chromosome and Y-chromosome are small acrocentric. A FN = 32 has also been reported, with all biarmed autosomes, and with a small acrocentric X-chromosome and a dot-like Y-chromosome. There is no sexual dimorphism in skull size and shape.

Habitat. Coastal and inner Atlantic Forests and cerrado, strongly associated with gallery forests.

Food and Feeding. The Northern Three-striped Opossum has been seen feeding on fruits or seeds of canopy palm ( Attalea oleifera ) in the Atlantic Forest of north-eastern Brazil. Nutritional contents of preferred diets, determined with cafeteria experiments in captivity where individuals were free to choose food items according to their needs, resulted in 0-62 g of proteins, 1-7 g of carbohydrates, 0-01 g of lipids and 2:3% of fibers per 100 g of dry matter.

Breeding. Nests of Northern Three-striped Opossums are made with leaves in tree forks, and their nests have been found at heights of ¢.5 m, even though they are often reported to be ground dwelling. In the cerrado in central Brazil, an adult male, seven subadult males, and one subadult female were collected in January-July, and it was suggested that, as other small species of opossums, the Northern Three-striped Opossum could present some level of semelparity, although they are not sexually dimorphic—a trait usually present in semelparous or partially semelparous opossums. In the same region, a lactating female was collected in November. In south-eastern Brazil, one study noted that females captured in October, May, and June had no young, while a two-year population study recorded presence ofjuveniles only in January-May, which corresponded to end of wet season and start of dry season. In this study, no individuals captured in one year were recaptured in the following year, also suggesting a pattern of semelparity, but numbers of captures were insufficient to adequately quantify survival rates.

Activity patterns. The Northern Three-striped Opossum is diurnal. In a gallery forest in the cerrado of central Brazil, individuals were always found in traps during late afternoon checks, thus indicating that they had been foraging during daytime. In northeastern Brazil when observing species visiting canopy palm Attalea oleifera to feed on fruits or seeds, four diurnal visits by Northern Three-striped Opossums were recorded.

Movements, Home range and Social organization. Northern Three-striped Opossums are generally considered to be ground dwelling, although their nests have been found at heights of 5 m. Home range size in a gallery forest of central Brazil was 0-04 ha, and densities were 50-150 ind/km?. In a gallery forest in a cerrado area of central Brazil, distances between consecutive captures averaged 35-8 m, with a maximum of 128-1 m.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Northern Three-striped Opossum has a wide distribution with a presumably large population, and it occurs in several protected areas. It is in need of a detailed taxonomic revision, and it may need to be reassessed depending on the outcome of such a revision.

Bibliography. Alho et al. (1986), Astua (2010), Astua et al. (2003), Barros (2013), Bonvicino et al. (2005), Cabrera (1958), D'Andrea et al. (1999), Davis (1947), Emmons & Feer (1997), Gardner (2005), Hershkovitz (1992a), Langguth & Lima (1988), Lemos et al. (2000), Mares & Ernest (1995), Mares et al. (1989), Melo & Sponchiado (2012), Miranda-Ribeiro (1936), Nitikman & Mares (1987), Paresque et al. (2004), Pavan et al. (2014), Pereira et al. (2008), Pimentel & Tabarelli (2004), Pine & Handley (2007), Redford & Eisenberg (1992), Rossi et al. (2012), Solari et al. (2012).

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. E Brazil, from E Para to coastal Santa Catarina, and inland W to Brasilia. Also mentioned from NE Argentina (Misiones), but specific identification of these records is questioned.