596.

Long-tongued Arboreal Mouse

Rhagomys longilingua

French: Rhagomys du Pérou / German: Langzungen-Baummaus / Spanish: Ratén arboricola de lengua larga

Other common names: Long-tongued Rhagomys

Taxonomy. Rhagomys longilingua Luna & Patterson, 2003, below “ Suecia,” a roadside settlement in Manu Biosphere Reserve along the Rio Cosnipata, 1900 m, Cusco, Peru.

Although the species is treated here as monotypic, intraspecific variation was detected among the few specimens collected.

Distribution. Known from scattered localities in E Andean slopes of C & SE Peru and CW Bolivia; a record known from S Ecuador apparently belongs to an undescribed species.

Descriptive notes. Head-body 89-103 mm, tail 93-104 mm, ear 12-1-14 mm, hindfoot 17-20 mm; weight 25-35 g. The Long-tongued Arboreal Mouse is a clearly differentiable small sigmodontine, characterized by spiny fur, small ears, and tail less than head-body length. Pelage is short and markedly spiny, and dorsal fur is more spiny than ventral fur. Dorsum is olive-brown, with strong hispid pattern resulting from spines and long, thin hairs. Venter from chin to interior sides offorefeet and hindfeet is ocherous buff, contrasting sharply with dorsum. Tail is weakly bicolored, only slightly paler below, and terminates in small tuft of hair; scales are arranged in annular pattern, with hairs grouped in triplets of samesize, shorterat tail base and becoming longer toward tip. Five manual digits are long with broad, squared, narrow, and short claws that minimally project beyond conspicuously blunt tips. Pes is short and broad with five digits, each with blunt tip bearing calloused surface; hallux is noticeably shortened and has nail rather than claw.

Habitat. Tropical montane cloud forests, on eastern slope of Andes at elevations of 450-2100 m.

Food and Feeding. Stomach of the holotypic Long-tongued Arboreal Mouse contained Diptera, Formicidae, and Lepidoptera, suggesting an insectivorous diet. Its long tongue might help collect insects from crevices.

Breeding. No information.

Activity patterns. The Long-tongued Arboreal Mouse is nocturnal. Several anatomical traits suggest arborealabilities; three offour specimens were collected in pitfall traps, and one was collected 1 m above the ground’s surface in a bamboothicket. These findings suggest that Long-tongued Arboreal Mice exploit ground and aboveground environments.

Movements, Home range and Social organization. No information.

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

Bibliography. D'Elia, Luna et al. (2006), Dunnum, Vargas & Patterson (2008), Luna (2015), Luna & Patterson (2003), Medina et al. (2017), Villalpando et al. (2006).