Proechimys cuvieri, Petter, 1978

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Echimyidae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 552-604 : 579-580

53.

Cuvier’s Spiny-rat

Proechimys cuvieri

French: Rat-épineux de Cuvier / German: CuvierKurzstachelratte / Spanish: Rata espinosa de Cuvier

Taxonomy. Proechimys cuvieri Petter, 1978 ,

“Saul (S21), Guyane francaise,” French Guiana.

Proechimys cuvieri is a member of the longicaudatus-species group. Monotypic.

Distribution. Amazon Basin from E Ecuador, NE Peru, SE Colombia, and W Brazil E to the Amazon River mouth and N through the Guianan Region of E Ven-ezuela, and the Guianas.

Descriptive notes. Head-body 211-

234 mm, tail 144-168 mm; weight 260-420 g. Cuvier’s Spiny-rat is moderate-sized, closely similar in external and craniodental characteristics to sympatric samples of the Shorttailed Spiny-rat ( P. brevicauda ) in the western part ofits distribution, but markedly distinct from sympatric Guyenne Spiny-rat ( P. guyannensis ) in the Guianan region. Overall color is dark reddish orange, with midline of back darker than sides, which contrast sharply with white venter. Specimens from western Brazil may have slight fulvous edge to ventral fur in some individuals, but generally bright white contrasts sharply with typically buffy venter of sympatric Short-tailed Spiny-rat. Dorsal surface of hindfoot of Cuvier’s Spiny-rat is dark on toes and lateral margins, but short hairs above metatarsals are silver, or at least distinctly paler in color than toes. This also generally contrasts with color pattern of the Short-tailed Spiny-rat, where dorsal surfaces of hindfeet are overall dark and dull. Tail averages 70% of head—body length, is sharply bicolored, and clothed in long, slightly curved and dark hairs that give it distinctly shaggy appearance—rather remarkable for a species of Proechimys . Nevertheless, tail scales are visible to the eye; scale annuli average 9-12/cm at mid-tail. Dorsal pelage is stiff to the touch, with well-developed aristiform spines averaging 0-9 mm in width and 20-21 mm in length. Some geographical variation in spine development is apparent, with narrower spines in those from the Guianan region and tips with whip-like extensions in those from south of the Amazon in eastern Brazil; rather blunt tipped spines characterize samples from elsewhere. Head, rump, and sides are devoid of spines, as with most species of Proechimys . Skull of Cuvier’s Spiny-rat is relatively large, with long but relatively broad rostrum and well-developed supraorbital ledges but with weakly developed temporal ridges. Incisive foramina are lyrate in shape, with only moderate posterior constrictions; posterolateral margins are flanged but not as strongly as in species such as the Short-tailed Spiny-rat, and extend onto palate forming only weak grooves; premaxillary part of septum is long and typically in contact with maxillary part, which may be either keeled or smooth; and vomer is slightly to well exposed ventrally. Groove on floor of infraorbital foramen is absent or only weakly developed,as is lateral flange ofthis groove. Post-orbital process of zygoma is well developed and formed completely by squamosal, or with only minimal jugal contribution. Mesopterygoid fossa is relatively broad but penetrates posterior palate into M?, with mean angles of 66-73°, depending on geographical sample. Cheekteeth are large, with length of maxillary tooth row greater or equal to 8:2 mm. Three folds are typically present on all four upper and lower cheekteeth, although some variation in number exists among geographical samples. In particular, dP, may have either 3—4 folds, and M, may likewise have either two or three folds. Counterfold formula is 3-3-3-3 / 3(4)-3-3-(2)3. Baculum is short (length 6-1-8-:6 mm) and broad (proximal width 5-3-6-7 mm; distal width 5-2-7-4 mm), with short shaft, expanded base, and deep medial notch at distal end that results in distinct apical extensions. Chromosomal complement is 2n = 28 and FN = 46-48.

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Habitat. Primarily lowland, non-seasonally flooded or terra firma rainforests but seasonally available parts of otherwise inundated rainforest from near sea level to elevations of ¢.500 m. Cuvier’s Spiny-rat also occurs in abandon gardens and second-growth forests. It is usually more abundant than the Guyenne Spiny-rat in early successional forest and edge-dominated habitats in the Guianan region. In French Guiana, most Cuvier’s Spiny-rats were captured on the ground, but two were captured in liana tangles up to 1 m aboveground. There it was found in well-drained primary forest, creekside forest, and secondary vegetation beside logs, at bases of trees, amongstilt roots, on top of logs, and under masses of fallen branches. Cuvier’s Spiny-rat is broadly sympatric with the Guyenne Spiny-rat throughout the Guianan region and northern Brazilian Amazon, and it may co-occur with up to four other species of Proechimys along Rio Jurua in western Brazil, including actual syntopy with up to three other species on the same terra firma trap lines.

Food and Feeding. Cuvier’s Spiny-rat has been reported to eat fruit, insect and seeds.

Breeding. In Rio Jurua in western Brazil, adult male Cuvier’s Spiny-rats were reproductively active at least from August to March, over the end of the dry season and beginning of the annual rainy season. Pregnant females were found only during the wet season in February-March, and a lactating female was obtained in August. Young individuals were trapped in most months between August and June. These data are insufficient to know if breeding is largely confined to the rainy season or extends over most of the year. Reported litter size was two embryos. In French Guiana, breeding was recorded year-round.

Activity patterns. There is no specific information available for this species, but Cuvier’s Spiny-rat is nocturnal and terrestrial.

Movements, Home range and Social organization. In French Guiana, Cuvier’s Spinyrats were monitored with radio-telemetry and fluorescent tracking. Male home ranges averaged at least twice the size of females; female home ranges were exclusive of other females; and male home ranges overlapped extensively with other residents of both sexes. These data suggested that Cuvier’s Spiny-rat is polygynous or promiscuous.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Cuvier’s Spiny-rat is widespread and occurs in several forest types, including those modified by humans, and in protected areas. It is unlikely to be declining. Additional studies on distribution, habitat, abundance, ecology, and conservation threats to Cuvier’s Spinyrat are needed.

Bibliography. Eisenberg & Redford (1999), Emmons (1990, 1997a), Guillotin (1982), Patton (1987), Patton & Gardner (1972), Patton & Leite (2015), Patton & Reig (1989), Petter (1978), Reig et al. (1980), Woods & Kilpatrick (2005).

Figures

12. Broad-headed Spiny-rat (Clyomys laticeps), 13. Guiara (Euryzygomatomys spinosus), 14. White-spined Spiny-rat (Irinomys albispinus), 15. Elias’s Spiny-rat (Trinomys eliasi), 16. Rigid-spined Atlantic Spiny-rat (Trinomys paratus), 17. Yonenaga’s Spiny-rat (Trinomys yonenagae), 18. Elegant-spined Atlantic Spiny-rat (Trinomys setosus), 19. Moojen’s Spiny-rat (Trinomys moojeni), 20. Pau Brasil Spiny-rat (Trinomys mirapitanga), 21. Rio de Janeiro Spiny-rat (Trinomys dimidiatus), 22. Sao Paulo Spiny-rat (Trinomys thering), 23. Gracile Atlantic Spiny-rat (Trinomys gratiosus), 24. Sao Lourenco Punare (Thrichomys laurentius), 25. Jacobina Punare (Thrichomys inermis), 26. Lagoa Santa Punare (Thrichomys apereoides), 27. Pantanal Punare (Thrichomys pachyurus), 28. Foster’s Punare (Thrichomys fosteri), 29. Painted Tree-rat (Callistomys pictus), 30. Coypu (Myocastor coypus), 31. Armored Rat (Hoplomys gymnurus)

Distribution. Amazon Basin from E Ecuador, NE Peru, SE Colombia, and W Brazil E to the Amazon River mouth and N through the Guianan Region of E Ven-ezuela, and the Guianas.