Cabassous unicinctus (Linnaeus, 1758)

Voss, Robert S. & Fleck, David W., 2017, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 2: Xenarthra, Carnivora, Perissodactyla, Artiodactyla, And Sirenia, Bulletin of the American Museum of Natural History 2017 (417), pp. 1-1 : 1-

Cabassous unicinctus (Linnaeus, 1758)

Figure 3C

VOUCHER MATERIAL (TOTAL = 2): Orosa (AMNH 74113), Río Manití (FMNH 112563).

OTHER INTERFLUVIAL RECORDS: Río Yavarí- Mirím (Salovaara et al., 2003), San Pedro (Valqui, 1999).

IDENTIFICATION: Both specimens of nakedtailed armadillos that we examined from the Yavarí-Ucayali interfluve conform to the diagnosis of Cabassous unicinctus in Wetzel’s (1980) revision of Cabassous . The Orosa specimen (AMNH

74113) was among those that Wetzel (1980) examined and assigned to the nominotypical subspecies (with type locality “Surinam”). According to this authority, C. u. unicinctus intergrades with a smaller subspecies, C. u. squamicaudis (Lund, 1843; type locality Minas Gerais, Brazil) in “the Amazon-Solimões River area in Brazil and Peru.” The material at hand is entirely inadequate to

assess geographic variation in this species, but it is noteworthy that cranial measurements of AMNH 74113 ( table 3 ) are much smaller than the mean values for C. u. unicinctus tabulated by Wetzel (1980: table 1), but they are close to the corresponding means for C. u. squamicaudis. However, the number of scutes on the cephalic shield of this specimen (N = 36) is much closer to the mean value tabulated for C. u. unicinctus (34.6 ± 2.2 SD; Wetzel, 1980: table 4 ) than it is to the mean value for C. u. squamicaudis (54.0 ± 5.5). The taxonomic significance of these conflicting indications is unclear, but the mean differences between Wetzel’s (1980) subspecies are substantial, and a fresh assessment of the material he allocated to these nominal taxa would seem to be appropriate in any future taxonomic study of Cabassous .

The second known specimen of Cabassous unicinctus from the Yavarí-Ucayali interfluve (FMNH 112563) consists only of a live-mounted skin of a specimen “caught swimming in the river” (P. Soini’s notation on skin tag); this specimen has 33 scutes on the cephalic shield. The skull, apparently, is lost.

ETHNOBIOLOGY: The naked-tailed armadillo has only one name, menkudu, which is not analyzable and has no cognate in other Panoan languages, but which may contain the adjective kudu (“grayish” or “light-colored”). No subtypes are named by the Matses, although some informants claim that there is more than one kind.

This species is not eaten by the Matses, and is of no economic importance. Very rarely a hunter will kill one out of curiosity.

If a hunter encounters a naked-tailed armadillo, it may cause his children to fall ill, in which case a medicine man will try several different medicinal plants, some of which are said to be specific to contagions caused by this species (other plants are said to be general remedies for contagions caused by any type of armadillo). Adults can become constipated due to exposure to a naked-tailed armadillo, in which case there is a specific plant to cure this. As is generally the case with rarely encountered animals, coming across a naked-tailed armadillo is interpreted as an omen that someone in the (extended) family of the person who sees it will fall ill and die soon thereafter.

MATSES NATURAL HISTORY: The naked-tailed armadillo is like a small giant armadillo. It is small, the size of a nine-banded long-nosed armadillo ( Dasypus novemcinctus ). It is lighter in color than other armadillos. Its front claws are large, the central ones as large as tablespoons (an obvious exaggeration). Its back feet are like those of a long-nosed armadillo. They are hairier than other armadillos. The tail is hard, but not ringed.

Naked-tailed armadillos are seldom seen and apparently very rare. Many Matses have never seen one, but burrows are somewhat frequently found. Their burrows are usually found in primary forest.

Naked-tailed armadillos sleep in burrows. The burrow has a small diameter, barely wide enough for the animal to fit. The burrow is deep and points straight down, unlike those of other armadillos, and one can recognize unquestionably that a burrow belongs to a naked-tailed armadillo. One informant found a naked-tailed armadillo sleeping in a hollow log. No leaf beds have been found in burrows of this species.

The naked-tailed armadillo is nocturnal. It roots at the bases of trees and digs into rotten logs. It walks around on the surface of the ground but also travels underground. It is very strong and can dig very quickly and very deep. It escapes by digging a deep hole in the ground, covering itself with excavated soil as it digs. It expels the dirt when it surfaces, as if it had dug up to the surface from another location. It does not make or use paths (as dasypodid armadillos are said to do; see below).

One informant saw three individuals of this species traveling together.

There are no flies at the entrances to burrows of this species (as there are at the burrow entrances of other sympatric armadillos; see below).

Naked-tailed armadillos are said to grunt by some informants, but others say they make no sounds.

The naked-tailed armadillo eats earthworms, millipedes, grubs that live in the ground, and other invertebrates. (Most informants had no idea what it eats, but they assumed it eats the same foods as long-nosed armadillos.)

REMARKS: Although sparse, Matses information about Cabassous unicinctus includes a few novel observations, notably that this species travels underground as well as on the surface. 1 The nocturnal activity reported by the Matses agrees with other rainforest observations ( Emmons, 1997), but not with the diurnal activity reported from Brazilian savanna habitats ( Bonato et al., 2008). The perpendicular orientation of burrows attributed to this species by the Matses is consistent with quantitative data on burrow characteristics summarized by Trovati (2015).

Figures

FIG. 3. Crania of four armadillo species that occur in the Yavarí-Ucayali interfluve, illustrating taxonomic differences in size and shape: Dasypus novemcinctus (A, AMNH 268229); D. pastasae (B, AMNH 268228); Cabassous unicinctus (C, AMNH 74113); Priodontes maximus (D, AMNH 93418). All illustrated specimens are adults, but AMNH 93418 is not from the Yavarí-Ucayali interfluve.

Tables

TABLE 3 Measurements (mm) and weights (g) of Adult Armadillo Specimens from the Yavarí-Ucayali Interfluve

	Cabassous unicinctus	Priodontes maximus	Dasypus novemcinctus		Dasypus pastasae
	AMNH 74113	MUSM 11091	AMNH 268229	MUSM 11089	AMNH 268228	MUSM 11083
Sex	female	male	female	female	female	male
Head-and-body length	480b	733	429	— a	532	481
Length of tail	145b	541	361	385	431	373
Hind foot	66b	190	— a	103	106	107
Ear	—	61	40	45	50	51
Condylonasal length	76.0	188.7	97.6	102.7	113.8	112.8
Zygomatic breadth	40.2	81.1	45.0	43.4	45.3	44.5
Least interorbital breadth	25.3	47.8	24.0	22.2	25.3	25.8
Breadth of braincase	32.0	64.7	33.7	32.4	34.6	35.0
Maxillary toothrow	26.0	69.8	24.0	26.5	30.2	29.5
Weight	—	35000	5300	5400	7700	5900

Measurements (mm) and weights (g) of Adult Armadillo Specimens from the Yavarí-Ucayali Interfluve

a Collector’s measurement is not plausible.

b Estimated from skin (no collector’s measurements).