Myoprocta pratti Pocock, 1913

Voss, Robert S., Fleck, David W. & Jansa, Sharon A., 2019, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 5. Rodents, Bulletin of the American Museum of Natural History 2024 (466), pp. 1-180 : 107-110

Myoprocta pratti Pocock, 1913

Figure 44

VOUCHER MATERIAL (N = 20): Boca Río Yaquerana (FMNH 88909), Jenaro Herrera (MUSM 23824), Nuevo San Juan (AMNH 268267, 268268; MUSM 11234, 11235 [not seen]), Orosa (AMNH 73857–73861, 74066– 74070), Quebrada Esperanza (FMNH 88910, 88911), San Fernando (FMNH 88908), Santa Cecilia (FMNH 86920). Additionally, Pavlinov (1994) reported ZMMU specimens from Jenaro Herrera that we have not seen.

UNVOUCHERED OBSERVATIONS: Río Yavarí ( Salovaara et al., 2003), Río Yavarí-Mirím ( Salovaara et al., 2003), San Pedro ( Valqui, 1999, 2001).

IDENTIFICATION: Specimens of Myoprocta collected in the Yavarí-Ucayali interfluve exhibit all the diagnostic traits of M. pratti (the so-called green acouchy), including grizzled brownish/olivaceous dorsal pelage; absence of a fringe of long, unbanded, and highly polished rump hairs; presence of a streak of white midventral hairs; a distinctive range of craniodental measurements (table 32); and widely open, teardrop-shaped sphenopalatine vacuities (Voss et al., 2001; Teta, 2019).

The taxonomy of Myoprocta species, commonly known as acouchies, was problematic for many years, the application of available names differing according to authors who variously emphasized geography versus pelage color to justify alternative usage. Among other relevant problems was the absence of a name-bearing type for M. acouchy (Erxleben, 1777) , the so-called red acouchy, but this difficulty was eventually resolved by the designation of a neotype from French Guiana. Voss et al. (2001) recognized two allopatric species of Myoprocta distinguishable both by qualitative characters and morphometric analysis: the red acouchy from northeastern Amazonia and the green acouchy from western Amazonia. Patton and Emmons (2015a) mapped the allopatric distributions of M. acouchy and M. pratti as recognized by Voss et al. (2001), but Ramírez-Chaves et al. (2014) suggested that these species are sympatric in eastern Colombia. Teta (2019) subsequently examined some of the Colombian specimens that Ramírez-Chaves et al. (2014) referred to M. acouchy , reidentified them as M. pratti , and concluded that these species are, in fact, allopatrically distributed. To date, there has been no molecular assessment of acouchy taxonomy.

Several authors have noted geographic variation in Myoprocta pratti and suggested that green acouchies might comprise a species complex. Indeed, many nominal taxa are currently treated as subjective junior synonyms of M. pratti (e.g., by Patton and Emmons, 2015a): these include milleri Allen, 1913; limanus Thomas, 1920; parva Lönnberg, 1921; archidonae Lönnberg, 1925; limana Thomas, 1926; caymanum Thomas, 1926; and pluralis Thomas, 1926. Because a comprehensive revision of green acouchies, is beyond the scope of this report, it does not seem useful to speculate about the application of these names, although we note the relative proximity of our collections to the type locality of the nominotypical form. 29

ETHNOBIOLOGY: The principal name for the green acouchy is tsatsin, which is not linguistically analyzable. It has one archaic synonym, çhoçhoşh, which seems to be of onomatopoetic origin (imitating the acouchy’s call). No subtypes are recognized by the Matses.

The acouchy can be classified as a minor game species, since it is quite small, infrequently killed, and not actively sought after; however, its meat is considered delicious. Acouchies are killed from hunting blinds built in the vicinity of fruiting trees. They are also, rather infrequently, killed with deadfall traps that are built principally for spiny rats ( Proechimys spp. ). They are occasionally shot when found feeding on manioc in Matses swiddens, although they are not otherwise considered to be worth a shotgun shell.

Acouchies are cooked by roasting, after singeing off the hairs and gutting (without skinning them). Acouchies are desirable pets, and hunters will take the young from burrows if they encounter any while hunting.

Young people are traditionally not allowed to eat acouchies (lest they grow thin and frail),

29 The type locality of Myoprocta pratti is not immediately obvious from the primary literature, although there is no substantive disagreement on this point among the secondary sources cited above. Pocock’s (1913: 110–111) original description was based on two specimens: the type (BMNH 13.7.17.1), said to have been presented to the Zoological Society by one Mr. Chavez, who brought it from the “Amazons,” and a paratype (BMNH 17.3.21.1) collected by a Mr. Pratt in Peru. Thus, Pocock’s text suggests that the type locality should be the “Amazons” (i.e., Amazonia), but Thomas (1920, 279, fn.) explained that Pratt collected his agoutis [sic] at the Pongo de Rentema on the Marañón, and a note in Thomas’s distinctive handwriting on the skin tag of BMNH 17.3.21.1 states that both specimens (Chavez’s and Pratt’s) were from the same expedition. The Pongo de Rentema (5°29′S, 78°31′W; DMA, 1989) is a narrow cataract just below the confluence of the Marañón with the Río Utcubamba on the border between the departments of Cajamarca and Amazonas, about 540 km west of our region.

although nowadays this and other dietary taboos have been relaxed.

MATSES NATURAL HISTORY: The acouchy is like a small version of the agouti . The acouchy is reddish, but grizzled with white, as if its hair had begun to turn gray. Its hairs are banded. It is small and has a short, thin tail with a white tip. Its head is like a squirrel’s and has whiskers on its snout. It runs very fast.

Acouchies are more common in primary than in secondary forest. They are encountered infrequently.

The acouchy dens in hollow logs, cavities at the base of hollow trees, and burrows in the ground, which it lines with dry leaves. (The Matses consider it remarkable that acouchy nests are not very deep, even nests with nursing young.)

The acouchy is strictly diurnal. It sets out at dawn and feeds all day on fallen tree fruits. When it finds ripe tree fruits, it buries them to dig up and eat later. It buries them in several holes, a bit far from the tree from which they fell. After burying fruits, it gathers more fruits into a pile and eats them. It comes back to eat more fruits in the late afternoon before retiring to its den. Where there are no ripe fruits on the ground, it digs up the fruits that it has buried. It digs into the ground searching for the palm nut or seeds of fruits it has buried, even if the ground is muddy. It wags its little tail as it comes to eat, and it wipes its snout with its forefeet after eating to clean off any residue. It drinks muddy water at mineral licks.

The acouchy is solitary. It raises its young in hollow logs or holes in the ground. It brings fruit to its den to feed its young.

Acouchies are preyed upon by ocelots, margays, jaguarundis, short-eared dogs, bush dogs, tayras, hawks, and eagles.

The acouchy yells out “chochochosh” as it flees when it sees people.

The acouchy principally eats dicot tree fruits of many types, especially those of bata ( Pseudolmedia spp. or Perebea spp. [ Moraceae ]) and bata mapipa ( Pseudolmedia macrophylla [ Moraceae ]). It also eats the seeds of dicot tree fruits whose pulp has rotted away, including seeds of tonnad (a general term for trees in the family Myristicaceae ). It also eats the endosperm of pinchuk palms ( Astrocaryum murumuru ). It eats manioc in Matses swiddens.

REMARKS: Three of the four specimens of Myoprocta pratti accompanied by capture data from our region were trapped on the ground in secondary upland forest (abandoned swiddens), but one was trapped on the ground in primary upland forest. Matses observations about green acouchies are entirely consistent with, and substantially complement, previously published accounts of Myoprocta behavior (e.g., Dubost, 1988; Emmons, 1997).