343.

Orces’s Andean Water Mouse

Chibchanomys orcesi

French: Ichthyomys d'Orces / German: Orces-Andenwassermaus / Spanish: Raton de agua de Orces

Other common names: Las Cajas Ichthyomyine, Las Cajas Water Mouse

Taxonomy. Chibchanomys orcesi Jenkins & Barnett, 1997, Lake Luspa, Las Cajas, Provincia Azuay, Ecuador.

This species is monotypic.

Distribution. S Ecuador to C Peru.

Descriptive notes. Head-body 103-107 mm, tail 108-122 mm, ear 9-14 mm, hindfoot 19-24 mm; weight 35-50 g. Orces’s Andean Water Mouse is relatively small. Dorsum is gray-black, contrasting silvery or pale-gray venter. Supraorbital vibrissae are absent, and pinnae are small and hidden by fur of head. Manus has five separate plantar pads. Pes has peripheral rigid silvery hairs, and claw of pedal fifth digit extends beyond first interphalangeal joint of fourth digit. Tail is longer than headbody length.

Habitat. Mountain streams in grassy paramo at elevations of 2400-3700 m.

Food and Feeding. Diet mainly consists of aquatic insects and smallfish.

Breeding. No information.

Activity patterns. Orces’s Andean Water Mouse is nocturnal and semi-aquatic.

Movements, Home range and Social organization. Orces’s Andean Water Mouse is solitary. It is a rare species, and has a low population density and restricted range.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. This classification 1s due to lack of information on extent of occurrence, threats, status, and ecological requirements of Orces’s Andean Water Mouse.

Bibliography. Barnett (1997 1999), Jenkins & Barnett (1997), Voss (2015b).