Reithrodon typicus, Waterhouse, 1837

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Cricetidae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 204-535 : 413

366.

Naked-soled Conyrat

Reithrodon typicus

French: Reithrodon de I'Uruguay / German: Nacktsohlige Kaninchenratte / Spanish: Rata conejo de plantas desnudas

Taxonomy. Reithrodon typicus Waterhouse, 1837 , Maldonado, Maldonado, Uruguay.

Reithrodon typicusis the type species of the genus. Two subspecies recognized.

Subspecies and Distribution.

R.t.typicusWaterhouse,1837—extremeSBrazil(RioGrandedoSulState)andUruguay.

R. t. currentium Thomas, 1920 — NE Argentina (Corrientes and Entre Rios provinces); range probably extends into extreme NE Buenos Aires Province.

Descriptive notes. Head-body 140-150 mm, tail 90-120 mm, ear 22-27 mm, hindfoot 27-35 mm; weight 60-105 g. See general characters of the genus under the North-western Conyrat ( R. caurinus ) account. Dorsum of the Naked-soled Conyrat is mixed buffy gray, sides and venter are strongly washed with buff; manus and pes are white; tail is almost white; and soles of forefeet and hindfeet are naked or tending to be less haired than those of the Hairysoled Conyrat ( R. auritus ). Chromosomal complementis 2n = 28, FN = 40.

Habitat. Natural or modified grasslands. In Uruguay, the Naked-soled Conyrat is usually found in overgrazed pasture, among rocky outcrops, and on well-drained slopes with scant vegetation. According to Darwin’s notes, who secured the holotype of the species in 1832, was frequent in small thickets in the open grassy fields near Maldonado.

Food and Feeding. The Naked-soled Conyrat is herbivorous; preferred plants in Uruguay include corms of Oxalis sp. (Oxalidaceae) and rhizomes and roots of Digitaria sp (Poaceae) . Naked-soled Conyrats took food into the main burrow of feed in specific shelters, but no food stores were found in burrows.

Breeding. Naked-soled Conyrats with reproductive signals have been trapped in spring and summer (October-May). Recorded numbers of embryos were 3-4; a lactating female had four nestling young.

Activity patterns. The Naked-soled Conyrat is nocturnal and terrestrial.

Movements, Home range and Social organization. Naked-soled Conyrats dig burrows in sandy to hard-baked clay soils, or use with or without modification abandoned burrows or natural crevices and holes among rocks. Nearness of burrows to each other suggests that they can be variously gregarious or solitary. Burrow entrances averaged 5 cm in diameter. A passageway descended vertically an average of 25 cm, where tunnels became level and followed a course parallel to the surface. Active systems were marked by fresh cuttings and droppings near entrances. An excavation showed that all burrows were less than 2 m in length and had two entrances; they were occasionally branched and tortuous; burrow entrances were 3-5 cm in diameter; tunnels were 5-7 cm in diameter and were 10-25 cm beneath the surface; some burrows contained central, oval chambers up to 30 cm in diameter; in one such chamber had a nest platform of fine dry grass; defecation sites were just outside entrances of burrows or within a 9m radius from them; no distinct runways led to any of these burrows.

Status and Conservation. Classified as Least Concern on The IUCN Red Last.

Bibliography. Barlow (1969), D'Elia (2016b), Freitas, Mattevi & Oliveira (1983), Gonzalez & Martinez (2010), Ortells et al. (1988), Pardinas & Galliari (2001), Pardinas, Galliari & Teta (2015), Thomas (1920b), Waterhouse (1839).

Figures

353. Bogota Grass Mouse (Neomicroxus bogotensts), 354. Ecuadorean Grass Mouse (Neomucroxus latebricola), 355. Altiplano Chinchilla Mouse (Chinchillula sahamae), 356. Small Red-nosed Tree Mouse (Juliomys pictipes), 357. Delicate Red-nosed Tree Mouse (Juliomys ossitenuis), 358. Montane Red-rumped Tree Mouse (Juliomys rimofrons), 359. Araucaria Forest Tree Mouse (Juliomys ximenezi), 360. Ruschi’s Spiny Mouse (Abrawayaomys ruschii), 361. Chebez’s Spiny Mouse (Abrawayaomys chebezi), 362. Montane Atlantic Forest Rat (Delomys altimontanus), 363. Pallid Atlantic Forest Rat (Delomys sublineatus), 364. Striped Atlantic Forest Rat (Delomys dorsalis), 365. North-western Conyrat (Reithrodon caurinus), 366. Naked-soled Conyrat (Reithrodon typicus), 367. Hairy-soled Conyrat (Reithrodon awritus), 368. Short-tailed Cane Mouse (Zygodontomys brevicauda), 369. Colombian Cane Mouse (Zygodontomys brunneus), 370. Ucayali South American Spiny Mouse (Scolomys ucayalensts), 371. Gray South American Spiny Mouse (Scolomys melanops), 372. Boquete Rice Rat (Nephelomys devius), 373. Santa Marta Rice Rat (Nephelomys maculiventer), 374. Mount Pirre Rice Rat (Nephelomys pirrensis), 375. Western Colombian Rice Rat (Nephelomys pectoralis), 376. Coastal Cordilleran Rice Rat (Nephelomys caracolus), 377. Merida Rice Rat (Nephelomys meridensis), 378. Child’s Rice Rat (Nephelomys childi), 379. White-throated Rice Rat (Nephelomys albigularis), 380. Greater Golden-bellied Rice Rat (Nephelomys aurirventer), 381. Gray-bellied Rice Rat (Nephelomys moerex), 382. Lesser Golden-bellied Rice Rat (Nephelomys nimbosus), 383. Keays’s Rice Rat (Nephelomys keaysi), 384. Nimble-footed Rice Rat (Nephelomys levipes), 385. Hammond's Rice Rat (Mindomys hammondi), 386. White-bellied Arboreal Rice Rat (Oecomys bicolor), 387. Yellow Arboreal Rice Rat (Oecomys flavicans), 388. Savanna Arboreal Rice Rat (Oecomys speciosus), 389. Long-furred Arboreal Rice Rat (Oecomys trinitatis), 390. Robert's Arboreal Rice Rat (Oecomys robert), 391. Unicolored Arboreal Rice Rat (Oecomys concolor), 392. Guianan Arboreal Rice Rat (Oecomys awyantepui), 393. King Arboreal Rice Rat (Oecomys rex), 394. Red Arboreal Rice Rat (Oecomys rutilus), 395. Brazilian Arboreal Rice Rat (Oecomys paricola), 396. Foothill Arboreal Rice Rat (Oecomys superans), 397. Dusky Arboreal Rice Rat (Oecomys phaeotis), 398. Mamore Arboreal Rice Rat (Oecomys mamorae), 399. Anderson’s Arboreal Rice Rat (Oecomys sydandersoni), 400. Franciscos’ Arboreal Rice Rat (Oecomys franciscorum), 401. Atlantic Forest Arboreal Rice Rat (Oecomys catherinae), 402. Cleber’s Arboreal Rice Rat (Oecomys cleber), 403. McConnell’s Rice Rat (Euryoryzomys macconnelli), 404. Emmons’s Rice Rat (Euryoryzomys emmonsae), 405. Big-headed Rice Rat (Euryoryzomys legatus), 406. Russet Rice Rat (Euryoryzomys russatus), 407. Bufty-sided Rice Rat (Euryoryzomys lamia), 408. Elegant Rice Rat (Euryoryzomys nitidus), 409. Long-whiskered Rice Rat (Transandinomys bolivaris), 410. Talamancan Rice Rat (Transandinomys talamancae), 411. Long-nosed Rice Rat “ Handleyomys (™ rostratus), 412. Chapman’s Rice Rat “ Handleyomys (” chapman), 413. Black-eared Rice Rat “ Handleyomys (™ melanotis), 414. Guerrero Rice Rat “ Handleyomys (™ guerrerensis), 415. Cloud Forest Rice Rat “ Handleyomys (” saturatior), 416. Highland Rice Rat “ Handleyomys (” rhabdops), 417. Alfaro’s Rice Rat “ Handleyomys (” alfaroi), 418. Colombian Western Andes Cloud Forest Mouse (Handleyomys fuscatus), 419. Colombian Central Andes Cloud Forest Mouse (Handleyomys intectus)

Subspecies and Distribution. R.t.typicusWaterhouse,1837—extremeSBrazil(RioGrandedoSulState)andUruguay. R. t. currentium Thomas, 1920 — NE Argentina (Corrientes and Entre Rios provinces); range probably extends into extreme NE Buenos Aires Province.