Didelphis marsupialis Linnaeus, 1758

Voss, Robert S., Fleck, David W. & Jansa, Sharon A., 2019, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 3: Marsupials (Didelphimorphia), Bulletin of the American Museum of Natural History 2019 (432), pp. 1-89 : 50-52

Didelphis marsupialis Linnaeus, 1758

VOUCHER MATERIAL (TOTAL = 7): Jenaro Herrera (AMNH 276703; MUSM 23797), Nuevo San Juan (AMNH 268213, 272836; MUSM 11025, 11027, 13282).

OTHER INTERFLUVIAL RECORDS: Actiamë ( Vriesendorp et al., 2006a), Divisor ( Vriesendorp et al., 2006b), Jenaro Herrera ( Fleck and Harder, 1995), Nuevo San Juan (three unvouchered sightings), San Pedro ( Valqui, 1999).

IDENTIFICATION: Didelphis marsupialis , the socalled common or black-eared opossum of Amazonia and Central America, is externally unmistakable ( Husson, 1978; Emmons, 1997), and although similar in most qualitative aspects of craniodental morphology to species of Philander ( Voss and Jansa, 2009) , it is so much larger in all dimensions that skulls, and even isolated teeth, are

easily identified. There is remarkably little genetic variation in this species throughout its geographic range (e.g., <1.6% mean sequence divergence at the cytochrome b locus among samples from Costa Rica to central Amazonia; Patton et al., 2000: fig. 39). Measurements of the few adult specimens from our region (table 18) overlap the range of variation reported by Patton et al. (2000) for material collected along the Rio Juruá in western Brazil, but our specimens are large by comparison with their tabulated sample means.

Although the name Didelphis marsupialis has been used consistently for many years to refer to the black-eared Amazonian opossum, Gurgel-Filho et al. (2015) resurrected the obsolete synonym D. karkinophaga Zimmermann, 1780 , for this species and proposed that Linnaeus’s (1758) epithet be used for the white-eared species that has long been known

TABLE 18

as D. albiventris Lund, 1841 . Their justification for thus disrupting current usage was discussed by Dias et al. (2018), who thought that a specimen in Uppsala might be the lectotype designated by Thomas (1911). Feijó and Voss (2019) disagreed, established that the lectotype is almost certainly lost, and designated a neotype for D. marsupialis to conserve prevailing usage of this name for the black-eared opossum of Amazonia.

ETHNOBIOLOGY: The common opossum is called mapiokos by the Matses, a term that is not analyzable and is not found in other Panoan languages. The Matses recognize its similarity to the opossums they call cheka, but they do not classify it as a type of cheka.

Common opossums are considered pests because they eat chickens at night. The Matses kill them when they find them near chicken coops. The Matses traditionally did not eat common opossums, but local nontribal Peruvians do, so a few Matses eat them now, but most do not because of their foul smell.

The Matses believe that when the common opossum vocalizes, it is a death omen. If it calls from the trees, a man will die, and if it calls from the ground a woman will die.

MATSES NATURAL HISTORY: The common opossum has a naked tail. It has dark hairs sprinkled with white hairs, as if its coat were turning gray. It has a white snout and large ears. It has a strong, foul odor that can be smelled from far away. One can readily detect its scent where it has passed by hours ago.

The common opossum is terrestrial and arboreal, but forages mostly on the ground. It is found in upland forest, floodplain forest, and along streams. It occurs in both primary and secondary forest. It comes to Matses swiddens to eat plantains and papayas. It makes its nest in hollow trees and in the crowns of isan palm trees ( Oenocarpus bataua ).

The common opossum is nocturnal and solitary. The female carries its young in its pouch and suckles them inside the pouch. It gives birth to many young.

The common opossum is eaten by jaguars, ocelots, and margays. It vocalizes saying “chocod chocod.”

The common opossum eats spiny rats and birds, including tinamous, that it finds nesting on or near the ground at night. It enters coops to eat chickens, and it also eats pet guans, crickets/ katydids, cockroaches, and rotten meat.

REMARKS: Of our seven specimens, two were trapped on the ground in a swamp-palm ( Mauritia flexuosa ) swamp, one was trapped on the ground in primary upland forest, one was trapped at a height of 9 m in a tree in primary upland forest, one was caught by hand 2 m above the ground on a sapling in primary upland forest, one was trapped by a Matses boy (probably on the ground in secondary forest), and one was shot by a mestizo hunter in unrecorded circum-

TABLE 19

stances (near Jenaro Herrera). The “common” opossum was far from common at Nuevo San Juan in 1999, when Matses hunters recorded only three sightings in 409 hours of night hunting: once perched at an unrecorded height on a vine in old secondary growth, once on a fallen tree next to a stream (habitat unrecorded), and once on the ground in hilltop primary forest.