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Rodents from southern Patagonian semi-arid steppes (Santa Cruz Province, Argentina)

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Abstract

The little-known mammalian fauna of southern Santa Cruz Province is studied by means of live-trapping and examination of owl pellets at 11 localities. Thirty-nine individuals of seven species were recorded in a total of 753 trap nights during the years of 2004 and 2005. Additionally, we identified 376 prey items from a total of 130 pellets cast by Barn owls (Tyto alba) and Magellanic horned owls (Bubo magellanicus). Abrothrix olivaceus [Waterhouse, 1839. The zoology of the Voyage of the Beagle. Part II: Mammalia., London.] and Eligmodontia sp. were the most abundant trapped species and the best represented in pellet samples. Other rodents identified were Ctenomys sp., Euneomys sp., Loxodontomys micropus, Microcavia australis, Mus musculus, Notiomys edwardsii, Oligoryzomys magallanicus, and Phyllotis xanthopygus. The mammal sampling effected by live-traps and owls was rarely coincident, with some species collected only by traps or by owls. New recording localities for N. edwardsii and O. magellanicus enlarge the known distribution of these species in Santa Cruz province by 270 km west and 70 km north, respectively.

Introduction

When Charles Darwin travelled along the Santa Cruz River (Santa Cruz Province, Argentina) during the months of April and May of 1834, he wrote in his diary: “Patagonia, poor as she is in some respects, can however boast of a greater stock of small rodents than perhaps any other country in the world. Several species of mice are externally characterised by large thin ears and a very fine fur. These little animals swarm amongst the thickets in the valleys, where they cannot for months together taste a drop of water excepting the dew” (Darwin, 1989 [1839]). As a result of the expedition between the mouth (Atlantic Ocean, 68°W) and the upper course of Santa Cruz River (near the Andean Cordillera; 71° W), Darwin collected the types of Mus micropus Waterhouse, 1837 (=Loxodontomys micropus), Mus xanthopygus Waterhouse, 1837 (=Phyllotis xanthopygus), Mus xanthorhinus Waterhouse, 1837 (=Abrothrix olivaceus), and Reithrodon cuniculoides Waterhouse, 1837 (=Reithrodon auritus). For the following 60 years, the knowledge of the small mammal communities from Santa Cruz Province has remained in a static situation. Between 1890 and 1920, another scientific expeditions reached the southern extreme of the Santa Cruz Province, exploring the western mountain ranges and the adjoining steppes or the Atlantic coast (e.g., Princeton Expedition to Patagonia [1896–1899]; J. Pemberton, for the Museo Argentino de Ciencias Naturales [1914–1915]; E. Budin for the British Museum of Natural History [1927–1928]). On the other hand, the widely extended semi-desert steppes along the course of the Santa Cruz River have remained virtually unexplored since the Darwin's voyage, near 170 years ago.

In this paper, we studied the mammalian fauna along the Santa Cruz and La Leona rivers and the areas of Lago Argentino and Lago Viedma (Santa Cruz province, Argentina), based on trapping data and analysis of owl pellets collected in several localities. Fieldwork was largely conducted during 2004 and 2005.

Section snippets

Study area and methods

The study area is mostly included in an ecotone between the dwarf shrub steppes of Nassauvia glomerulosa, Nassauvia ulicina and Chuquiraga aurea (locally known as eriales) and the shrubby steppes of Junellia tridens of the Central District of the Patagonian Phytogeoghapic Province (León et al., 1998) (Fig. 1). Towards the south and west, these formations are intermixed with the herbaceous steppes of the Subandean District of the same phytogeographic province. Climate is cold and semi-arid, with

Results and discussion

Thirty-nine individuals of seven species were recorded in a total of 753 trap nights (Table 1). A. olivaceus (Waterhouse, 1839) and Eligmodontia sp. were the most abundant trapped species. Other trapped taxa included L. micropus, Microcavia australis I. Geoffroy et d’Orbigny, 1833, Mus musculus Linnaeus, 1758, P. xanthopygus, and Oligoryzomys magellanicus (Bennett, 1835). Two species of the genus Eligmodontia are present in Patagonia (Sikes et al., 1997): E. typus Cuvier, 1837 and E. morgani J.

Acknowledgements

Silvana Peiretti and Karina Hodara greatly improved the writing of this paper. We would like to thank the editor and two anonymous reviewers for providing useful comments on a first version of the manuscript. Special thanks are extended to our field colleagues, Carlos Albrieu and Julio Monguillot. Financial support was provided by Unidad Académica Río Gallegos, Universidad de la Patagonia Austral (UNPA, Santa Cruz, Argentina).

References (25)

  • F.M. Jaksic et al.

    Small mammals of the Atacama Desert (Chile)

    Journal of Arid Environments

    (1999)
  • Bilenca, D.N., Busch, M., Gómez Villafañe, I.E., Miño, M.H., Pardiñas, U.F.J., Podestá, D.H., Súarez, O.V., in press....
  • Darwin, C., 1989 [1839]. The Voyage of the Beagle, Penguin Books....
  • H.F. del Valle et al.

    Status of desertification in the Patagonian Region: assessments and mapping from satellite imagery

    Arid Soil Research and Rehabilitation

    (1988)
  • M.H. Gallardo et al.

    Systematics of Oryzomys longicaudatus (Rodentia: Muridae) in Chile

    Journal of Mammalogy

    (1990)
  • P. Hershkovitz

    Evolution of Neotropical Cricetine Rodents (Muridae) with special reference to the Phyllotine group

    Fieldiana, Zoology, New Series

    (1962)
  • D.A. Kelt

    The natural history of small mammals from Aisen Region, southern Chile

    Revista Chilena de Historia Natural

    (1994)
  • K.M. Kramer et al.

    Phyllotis xanthopygus

    Mammalian Species

    (1999)
  • C. Lanzone et al.

    Citotaxonomía y distribución del género Eligmodontia (Rodentia, Cricetidae, Sigmodontinae)

    Mastozoología Neotropical

    (2005)
  • León, R.J.C., Bran, D., Collantes, M., M., P.J., Soriano, A., 1998. Grandes unidades de vegetación de la Patagonia...
  • Monjeau, A., 1989. Ecología y distribución geográfica de los pequeños mamíferos del Parque Nacional Nahuel Huapi y...
  • J.A. Monjeau et al.

    Plants, small mammals, and the hierarchical landscape classifications of Patagonia

    Landscape Ecology

    (1998)

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