Thomasomys paramorum, Thomas, 1898

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 : 496

640.

Paramo Oldfield Mouse

Thomasomys paramorum

French: Thomasomys du paramo / German: Eigentliche Paramomaus / Spanish: Raton de erial de paramo

Other common names: Paramo Thomasomys

Taxonomy. Thomasomys paramorum Thomas, 1898 , “Paramo, south of Chimborazo.” Defined by R. S. Voss in 2003 as “Urbina (1°30” S, 78°44’ W) just a few kilometers SE of Chimborazo,” Chimborazo, Ecuador.

Thomasomys paramorum exhibits some geographical polymorphism in several characteristics that might suggest a species complex. Monotypic.

Distribution. W Andes Range of S Colombia and Andes of Ecuador S to Huancabamba Depression.

Descriptive notes. Head-body 84-114 mm, tail 113-133 mm, hindfoot 23-26 mm, ear 15-19 mm; weight 17-26 g. Dorsum of the Paramo Oldfield Mouse is evenly brownish olive to reddish brown, venter is pale gray to whitish, creamy line separates flank and abdomen, and moderate countershading occurs between dorsum and venter. Mystacial vibrissae are moderately long, extending slightly beyond posterior margin of pinnae when bent. Ears are relatively large, evenly rounded, well-haired, and dark brown. Tail is short to moderately long (101-147% of head—body length), wellhaired, and incipiently bicolored brown above and paler below, occasionally with terminal white tip. Hands and feet are whitish above. Hindfoot is relatively short; gap is present between thenar and hypothenar pads. A Paramo Oldfield Mouse was reported with leucism.

Habitat. Primary, secondary, and recently disturbed forests, typically with moist mossy ground cover, fallen logs, and proximity to stands of Chusquea (Poaceae) bamboo, but not in paramo, on Cajas Plateau, northern Ecuador; subalpine rainforest, Polylepis (Rosaceae) thickets, paramo, and shrubby paramo and forest ecotone at Papallacta, northern Ecuador; forests of Polylepis and paramo of frailejon ( Espeletia , Asteraceae ) in El Angel Ecological Reserve, also northern Ecuador; elevations of 2000-4300 m.

Food and Feeding. The Paramo Oldfield Mouse is frugivore and herbivore.

Breeding. A female Paramo Oldfield Mouse with one embryo was captured at the end ofJune.

Activity patterns. The Paramo Oldfield Mouse is nocturnal and both terrestrial and arboreal.

Movements, Home range and Social organization. The Paramo Oldfield Mouse moves with agility through small tunnels under ground vegetation, easily climbs trees, and moves between them by the canopy. It builds its nest under roots and among dead leaves of Espeletia shrubs 0-15-15 m above the ground’s surface. This species emits dominant vocalizations at 1-6-1-9 kHz.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Paramo Oldfield Mouse is the most abundant species in El Angel Ecological Reserve.

Bibliography. Barnett (1999), Boada (2013), Brito & Batallas (2014), Brito & Valdivieso-Bermeo (2016), Brito, Teska & Ojala-Barbour (2012, 2015), Carleton (1973), Ellerman (1941), Gardner & Patton (1976), Haynie et al. (2006), Lee et al. (2011), Pacheco (2003, 2015b, 20169), Voss (2003).

Figures

622. Unicolored Oldfield Mouse (Thomasomys monochromos), 623. Venezuelan Oldfield Mouse (Thomasomys emeritus), 624. Dressy Oldfield Mouse (Thomasomys vestitus), 625. Woodland Oldfield Mouse (Thomasomys hylophilus), 626. Niceforo Maria’s Oldfield Mouse (Thomasomys nicefor), 627. Popayan Oldfield Mouse (Thomasomys popayanus), 628. Shortfaced Oldfield Mouse (Thomasomys baeops), 629. Snow-footed Oldfield Mouse (Thomasomys niveipes), 630. Principal Oldfield Mouse (Thomasomys princeps), 631. Silky Oldfield Mouse (Thomasomys bombycinus), 632. Red Andean Oldfield Mouse (Thomasomys auricularis), 633. Cinnamon-colored Oldfield Mouse (Thomasomys cinnameus), 634. Central Andes Oldfield Mouse (Thomasomys contradictus), 635. Ashy-bellied Oldfield Mouse (Thomasomys cinererventer), 636. Colombian Oldfield Mouse (Thomasomys dispar), 637. Soft-furred Oldfield Mouse (Thomasomys laniger), 638. Ash-colored Oldfield Mouse (Thomasomys cinereus), 639. Wandering Oldfield Mouse (Thomasomys erro), 640. Paramo Oldfield Mouse (Thomasomys paramorum), 641. Forest Oldfield Mouse (Thomasomys silvestris), 642. Smoky Oldfield Mouse (Thomasomys fumeus), 643. Pichincha Oldfield Mouse (Thomasomys vulcani), 644. Ucucha Oldfield Mouse (Thomasomys ucucha), 645. Taczanowski’s Oldfield Mouse (Thomasomys taczanowsku), 646. Golden Oldfield Mouse (Thomasomys aureus), 647. White-tipped Oldfield Mouse (Thomasomys caudivarius), 648. Hudson's Oldfield Mouse (Thomasomys hudsoni), 649. Reddish-backed Oldfield Mouse (Thomasomys pyrrhonotus), 650. Montane Oldfield Mouse (Thomasomys oreas), 651. Cajamarca Oldfield Mouse (Thomasomys praetor), 652. Distinguished Oldfield Mouse (Thomasomys notatus), 653. Apeco Oldfield Mouse (Thomasomys apeco), 654. Peruvian Oldfield Mouse (Thomasomys eleusis), 655. Strong-tailed Oldfield Mouse (Thomasomys ischyrus), 656. Reddish-nosed Oldfield Mouse (Thomasomys rosalinda), 657. Large-eared Oldfield Mouse (Thomasomys macrotis), 658. Ashaninka Oldfield Mouse (Thomasomys onkiro), 659. Inca Oldfield Mouse (Thomasomys incanus), 660. Kalinowski’s Oldfield Mouse (Thomasomys kalinowskii), 661. Slender Oldfield Mouse (Thomasomys gracilis), 662. Daphne’s Oldfield Mouse (Thomasomys daphne), 663. Anderson’s Oldfield Mouse (Thomasomys andersoni), 664. Austral Oldfield Mouse (Thomasomys australis), 665. Ladew’s Oldfield Mouse (Thomasomys ladewi)

Distribution. W Andes Range of S Colombia and Andes of Ecuador S to Huancabamba Depression.