Oxymycterus rufus (Fischer, 1814)

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 : 467

536.

Red Hocicudo

Oxymycterus rufus

French: Hocicudo roux / German: Rote Grabmaus / Spanish: Ratén hocicudo rojo

Other common names: Rufous Hocicudo

Taxonomy. Mus rufus G. Fischer, 1814 , “ Paraguay.” Restricted by P. Hershkovitz | in 1994 to “32°30°S in the Rio Parana drainage system; ... northern Entres Rios, Argentina.”

Considerable discussion about the type locality of this taxon was addressed by J. A. Oliveira and P. R. Goncalves in 2015, with designation of a neotype with provenance of Estancia San Juan Poriahu, Corrientes, Argentina . Traditionally, O. rufus has been referred to in the literature as O. rutilans. An isolated population in Minas Gerais State, referred to as this species needs closer taxonomical attention. Monotypic.

Distribution. C & E Argentina , with an isolated population in Minas Gerais State, SE Brazil.

Descriptive notes. Head—body 129-161 mm, tail 69-118 mm, ear 14-20 mm, hindfoot 27-32 mm; mean and extreme weights for scrotal males 92 g (62-125 g, n = 82) and for perforate females 76 g (46-110 g, n = 39). See general characters of the genus under the Amazonian Hocicudo ( O. amazonicus ) account. The Red Hocicudo is a moderately large species of Oxymycterus . Dorsum is cinnamon brown, strongly lined with black on head and mid-dorsum and ocherous tawny on rump and sides, to paler in which black component is less conspicuous; some individuals are strongly reddish. There are two types of guard hairs (banded and unbanded) varying in intensity of tone and length. Venter is ocherous orange.

Habitat. Wet grasslands with dense herbaceous cover in coastal areas to hilly habitats from sea level to elevations of ¢.2000 m.

Food and Feeding. The Red Hocicudo mainly eats small soil invertebrates: arthropods, annelids, and nematodes; plants account for 15-20% ofits diet. Stomachs from northern Buenos Aires Province contained 20% oligochetes, 60% arthropods, 5% other animals, 15% vegetation (mostly seeds and pollen), and traces of mice.

Breeding. In the southern pampas of Argentina breeding occurred at all seasons,litters averaged 3-1 young, weaning occurred at 14 days old, and sexual maturity was reached at c.3 months. Survival rate was 70-76% in summer and 92% in winter. In north-eastern Buenos Aires Province, breeding began late in September and continued into May.

Activity patterns. The Red Hocicudo is terrestrial. It is nocturnal or diurnal, varying geographically. In northern Buenos Aires Province, activity was mostly nocturnal with a peak between 17:00 h and 21:00 h and another between 3:00 h and 9:00 h. In southern Buenos Aires Province, activity was mostly diurnal as revealed by low incidence in owl pellets.

Movements, Home range and Social organization. Female Red Hocicudos averaged 69-2% of a population in south-eastern Buenos Aires Province, Argentina , from December to April. Maximum density occurred in winter and minimum in summer (February); most of the population was renewed annually. No burrows or runways were attributable to Red Hocicudos.

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

Bibliography. d/ Azara (1801, 1802), Bonaventura et al. (1991), Contreras & Teta (2003), Cueto, Piantanida & Cagnoni (1995), Cueto, Sanchez & Piantanida (1995), Dalby (1975), Goncalves & Oliveira (2004), Hershkovitz (1994), Kravetz (1972), Massoia (1961), Oliveira (1998), Oliveira & Goncalves (2015), Pardinas, D'Elia & Teta (2016), Reig (1965, 1982, 1987), Suérez (1994).

Figures

523. Huanchaca Burrowing Mouse (Juscelinomys huanchacae), 524. Candango Burrowing Mouse (Juscelinomys candango), 525. Amazonian Hocicudo (Oxymycterus amazonicus), 526. Spy Hocicudo (Oxymycterus delator), 527. Atlantic Forest Hocicudo (Oxymycterus dosytrichos), 528. Quaestor Hocicudo (Oxymycterus quaestor), 529. Inca Hocicudo (Oxymycterus inca), 530. Paramo Hocicudo (Oxymycterus paramensis), 531. Elfin Forest Hocicudo (Oxymycterus nigrifrons), 532. Upper Yungas Inca Hocicudo (Oxymycterus juliacae), 533. Small Yungas Hocicudo (Oxymycterus hiska), 534. Quechuan Hocicudo (Oxymycterus hucucha), 535. Mount Caparao Hocicudo (Oxymycterus caparoae), 536. Red Hocicudo (Oxymycterus rufus), 537. Darwin’s Hocicudo (Oxymycterus nasutus), 538. Ravine Hocicudo (Oxymycterus wayku), 539. Cook’s Hocicudo (Oxymycterus joser), 540. Common Cerrado Mouse (Thalpomys cerradensis), 541. Hairy-eared Cerrado Mouse (Thalpomys lasiotis), 542. Roraima Mouse (Podoxymys roraimae), 543. Blackish Grass Mouse (Thaptomys nigrita), 544. Ecuadorean Akodont (Necromys punctulatus), 545. Northern Akodont (Necromys urichi), 546. Hairy-tailled Akodont (Necromys lasiurus), 547. Pleasant Akodont (Necromys amoenus), 548. White-chinned Akodont (Necromys lactens), 549. Lillo’s Akodont (Necromys lilloi), 550. Dark-furred Akodont (Necromys obscurus), 551. Kemp's Grass Mouse (Deltamys kempi), 552. Araucaria Grass Mouse (Deltamys araucaria), 553. Serra do Mar Grass Mouse (Castoria angustidens)

Distribution. C & E Argentina , with an isolated population in Minas Gerais State, SE Brazil.