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Northern Andean Water Mouse

Chibchanomys trichotis

French: Ichthyomys chibchan / German: Nordliche Andenwassermaus / Spanish: Raton de agua septentrional

Other common names: Chibchan Ichthyomyine, Chibchan Water Mouse

Taxonomy. Ichthyomys trichotis Thomas, 1897, “W. Cundinamarca, in low country near to Magdalena R[iver, Colombia].”

Chibchanomys trichotis 1s the type species of the genus. Monotypic.

Distribution. E Andes Range in extreme SW Venezuela and NC Colombia.

Descriptive notes. Head-body 113-125 mm, tail 115-133 mm, ear 6-10 mm, hindfoot 30-33 mm; weight 35-50 g. Dorsum of the Northern Andean Water Mouse is dull gray or black, contrasting pale gray venter. Tail is longer than headbody length. There are no supraorbital vibrissae, and pinnae are hidden in fur of head. Manus has five separate plantar pads. Pes has well-developed fringe of stiff, silvery hair, and claw of pedalfifth digit extends beyond first interphalangeal joint of fourth digit.

Habitat. Small mountain streams bordered by cloud forest at of 2400-2900 m.

Food and Feeding. The Northern Andean Water Mouse eats aquatic insects, including larval beetles ( Scirtidae = Helodidae), larval crane flies ( Tipulidae), larval caddisflies ( Leptoceridae), and nymphs of mayflies ( Leptophlebiidae and Tricorythidae) and stoneflies ( Perlidae).

Breeding. An adult Northern Andean Water Mouse trapped in middle of dry season (January) had a single near-term embryo.

Activity patterns. The Northern Andean Water Mouse is semi-aquatic and probably nocturnal.

Movements, Home range and Social organization. No information.

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

Bibliography. Gbmez-Laverde et al. (2008), Jenkins & Barnett (1997), Thomas (1897b), Voss (1988, 2015b).