495.

Large Fernandina Galapagos Mouse

Nesoryzomys narboroughi

French: Oryzomys de Narborough / German: Grof 3e Fernandina-Galapagosratte / Spanish: Ratén de Galapagos de Fernandina grande

Other common names: Large Fernandina Nesoryzomys

Taxonomy. Nesoryzomys narboroughi Heller, 1904, Mangrove Point, Fernandina [= Narborough] Island, Galapagos Islands, Ecuador.

Nesoryzomys narboroughi is the type species of the genus. It is considered here a distinct species, different from N. indefessus. Monotypic.

Distribution. Restricted to Fernandina I, Galapagos Is.

Descriptive notes. Head-body 110-172 mm, tail 100-152 mm, ear 13-23 mm, hindfoot 29-33 mm; weight 77-136 g. The Large Fernandina Galapagos Mouse is a large species of Nesoryzomys . Pelage long and dense. Dorsum is dark brown to black. Back hairs are bicolored or tricolored, always with gray bases. Venter is paler than dorsum. Ears are large and obvious, naked in appearance but covered with fine hair. Tail is bicolored. White feet are distinguishing characteristics of the Large Fernandina Galapagos Mouse and are apparent on adults and subadults.

Habitat. All habitats of Fernandina, including coastal sites with saltbush ( Cryptocarpus pyriformis, Nyctaginaceae) and mangrove up to high elevations where Scalesia microcephala, Darwiniothamnus tenuifolius, both Asteraceae, and mixed grasses dominate.

Food and Feeding. The Large Fernandina Galapagos Mouse eats vegetation and insects. There are also records of crabs (Grapsus grapsus) in stomach contents.

Breeding. Reproduction is apparently limited to the rainy season (January-April).

Activity patterns. Large Fernandina Galapagos Mice are terrestrial and nocturnal. They take refuge in cavities or cracks in the ground between rocks or vegetation.

Movements, Home range and Social organization. Population at Cape Douglas was estimated at 100 ind/ha and was restricted to small patches of forest.

Status and Conservation. Classified as Vulnerable on The IUCN Red List.

Bibliography. Dowler (2015), Dowler & Carroll (1996), Dowler et al. (2000), Heller (1904), Johnson (2009), Key & Munoz (1994), Musser & Carleton (2005), Patton & Hafner (1983), Tirira (2017), Tirira, Dowler et al. (2008c¢).