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Morgan’s Gerbil Mouse

Eligmodontia morgani

French: Eligmodonte de Morgan / German: Morgan-Hochlandwiistenmaus / Spanish: Raton colilargo de Morgan

Other common names: Western Patagonian Laucha

Taxonomy. Eligmodontia morgan: J. A. Allen, 1901, “Arroya Else, Patagonia.” Restricted by M. I. Christie and U. F. J. Pardinas in 2016 to Ecker River, c.10 km SSW its junction with Pinturas River, Santa Cruz, Argentina.

Eligmodontia morgani was mostly resurrected based on karyological evidence, which was later supported with molecular data; morphological characterization of morgani is needed. Monotypic.

Distribution. WC & S continental Argentina and Chile.

Descriptive notes. Head-body 83-95 mm, tail 70-89 mm, ear 15-16-5, hindfoot 20-23 mm; weight 12-24 g (values for males and females from north-western Santa Cruz Province, Argentina). See general characters of the genus under the Hairy-footed Gerbil Mouse ( E. hirtipes) account. Morgan’s Gerbil Mouse is one of largest species of Eligmodontia, with tail typically shorter than head—body length, bicolored with narrow dark dorsalstripe, and ending in short apical tuft. Dorsum is dark to grayish brown, with yellowish mottled; intensity of yellow increases laterally and caudally, but most specimens are darkerrelative to those of other species. Dorsum separated from whitish venter by narrow ocherous lateral line; venter has gray to black bases of hairs visible, and tips are white. Ears are dark brown and noticeably short (¢.20% of head-body length). Length and general condition offur are more long and soft in southern populations and more close and short in northern populations. Dorsal surfaces of forefeet and hindfeet are covered with short, white hair. Chromosomal complement is 2n = 32— 34, FN = 32.

Habitat. Desert and subhumid southern habitats from high Andean steppes, Monte Desert shrublands, basaltic tablelands, rocky expositions, grassy ecotonal steppes near Nothofagus (Nothofagaceae) forests, coastal deserts, and wastelands from sea level to elevations of ¢.3500 m.

Food and Feeding. No information.

Breeding. Morgan's Gerbil Mouse breeds in October—April. Litters average 5-9 young. Individuals reached sexual maturity at 1-5 months old, and life span was c.9 months (one captive individual lived 27 months).

Activity patterns. Morgan’s Gerbil Mouse is terrestrial and nocturnal.

Movements, Home range and Social organization. In north-western Patagonia, density was highest in autumn (3-5 ind/ha) and lowest in spring (0-4 ind/ha). Home ranges were larger for females (656-7 m?) than males (439-6 m®).

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

Bibliography. Allen (1901¢, 1905), Chebez et al. (2014), Christie & Pardinas (2016), Coyner & Braun (2014), Da Silva (2011), Hershkovitz (1962), Hillyard et al. (1997), Kelt (1994), Kelt et al. (1991), Lanzone et al. (2015), Lessa et al. (2010), Lozada et al. (2001), Mann (1978), Monjeau (1989), Monjeau etal. (1997), Monteverde et al. (2011), Ojeda & Pardinas (2016), Ortells et al. (1989), Osgood (1943a), Pardinas, Teta, Cirignoli & Podesta (2003), Pardinas, Teta, D'Elia & Lessa (2011), Pearson (1995), Pearson et al. (1987), Sikes et al. (1997), Tiranti (1997), Zambelli et al. (1992).