744.

Bonarian Leaf-eared Mouse

Phyllotis bonariensis

French: Phyllotis de Buenos Aires / German: Buenos-Aires-Blattohrmaus / Spanish: Ratén orejudo de Buenos Aires

Other common names: Buenos Aires Leaf-eared Mouse

Taxonomy. Phyllotis darwini [sic] bonartensis Crespo, 1964, Abra de la Ventana, 500 m, Parque Provincial Ernesto Tornquist, Buenos Aires, Argentina.

Taxonomy of P. bonariensis is uncertain and needs additional research. Monotypic.

Distribution. Known only from Sierra de la Ventana, SW Buenos Aires Province, EC Argentina .

Descriptive notes. Head-body 127-151 mm, tail 110-147 mm, ear 23-25 mm, hindfoot 25-28 mm; weight 62-110 g (ranges from type series of 15 adults in nonbreeding season, and hindfoot probably measured without claw). Males are slightly larger than females. The Bonarian Leaf-eared Mouse is large. Ears and hindlegs are relatively small, vibrissae are well-developed, dorsum is light, venter is gray white, and flanks and belly are very well-defined. Tail is bicolored with scarce hairs, paler than body, almost withoutapical tuft, and slightly shorter than head-body length. Pectoral band is buffy and very slightly marked.

Habitat. Hilly environments, including rocky expositions surrounded by natural or modified grasslands and shrublands, at elevations of 500-1200 m.

Food and Feeding. Several stomachs of Bonarian Leaf-eared Mice contained finely homogenous green material.

Breeding. Bonarian Leaf-eared Mice with reproductive signals are recorded in spring (October-November) and early summer (December—January). A pregnant female captured in December gave birth to three young, and all females in the type series from late October had embryos. Seventeen individuals caught in May were females with imperforate vaginas and males with abdominaltestes.

Activity patterns. The Bonarian Leaf-eared Mouseis terrestrial and nocturnal.

Movements, Home range and Social organization. Bonarian Leaf-eared Mice were caught in crevices and sheltered locations in rocky exposures.

Status and Conservation. Classified as Near Threatened in The IUCN Red List. Although the Bonarian Leaf-eared Mouse is considered common,it occurs in less than 5000 km?, and extent and quality of its habitat are declining, perhaps making it close to qualifying as Vulnerable. Nevertheless, it is widespread along the Sierra de la Ventana system (c.50 km), and sampled populations appear healthy regardless of the extensive human modification of natural landscapes. In this context, the Bonarian Leaf-eared Mouse might be best classified as Least Concern.

Bibliography. Crespo (1964), Pardinas & Jayat (2008), Steppan & Ramirez (2015).