Metachirus nudicaudatus (E. Geoffroy)

VOSS, ROBERT S., LUNDE, DARRIN P. & SIMMONS, NANCY B., 2001, The Mammals Of Paracou, French Guiana: A Neotropical Lowland Rainforest Fauna Part 2. Nonvolant Species, Bulletin of the American Museum of Natural History 2001 (263), pp. 1-236 : 50-52

Metachirus nudicaudatus (E. Geoffroy)

VOUCHER MATERIAL: AMNH 266435, 266439, 266440, 266449, 266450, 266452, 266453, 266455, 267009, 267010, 267362, 267365; MNHN 1995.905–1995.910. Total = 18 (not including suckling young).

IDENTIFICATION: Our voucher material is al­

most topotypical of this species, which was originally described from a specimen collected at Cayenne (Julien­Laferrière, 1994). The Paracou series agrees closely in qualitative external characters with the description given by Husson (1978), and most craniodental measurements of the type fall within the range of metric variation in our voucher collection (table 11).

Although Metachirus has long been thought to contain but a single valid species (Tate, 1939; Cabrera, 1958; Gardner, 1993), this historical consensus is challenged by recently analyzed mtDNA sequences that suggest deep evolutionary divergence among samples from different Amazonian subregions (Patton et al., 2000). In the absence of any revisionary analysis of morphological specimens, however, it is unclear how mitochondrial haplotypes might correspond with named taxa. Inevitably, nominotypical material from French Guiana will play a pivotal role in any future attempt to resolve this unsatisfactory state of affairs.

REMARKS: We agree with Julien­Laferrière (1994) that the name Didelphis nudicaudata is available from Geoffroy’s (1803) catalog for the reasons explained by Hershkovitz (1955) and Holthuis (1963).

OTHER SPECIMENS EXAMINED: French Guiana —Cayenne (MNHN 1990.420 [holotype]).

FIELD OBSERVATIONS: We recorded 22 observations of Metachirus nudicaudatus at Paracou, of which 18 are based on collected specimens and 4 are unvouchered sightings. Eighteen records (82%) are of animals shot or sighted on the ground, but one specimen (4%) was trapped on the ground in a Tomahawk live trap, and three specimens (14%, all juveniles) were taken in Victor snap­traps tied to lianas 0.5–1.3 m above the ground. All of our records are from animals shot, sighted, or trapped at night. Fourteen indi­ viduals (64%) were shot, sighted, or trapped in well­drained primary forest, but one (4%) was encountered in swampy primary forest, four (18%) in primary forest of unspecified character, and three (14%) in secondary vegetation. With the exception of females with nursing young, all shot, sighted, or trapped animals were solitary.

One female shot on 7 July 1991 had seven nursing young measuring 19 mm crownrump, and another shot on 17 August 1991 had eight nursing young measuring 29 mm crown­rump.