Daniel E. Udrizar Sauthier

Distribution and use of burrows and tunnels ofChaetophractus villosus (Mammalia, Xenarthra) in the eastern Argentinean pampas

Burrows and tunnels built byChaetophractus villosus (Desmarest, 1804) (hairy armadillo) were studied in a farming area located in the Argentinean pampas, Buenos Aires Province, Argentina. Fifty-six structures were selected and carefully excavated for this study. Data on diameter, form, and orientation of the entrance, angle, length, and depth of the galleries, and spatial distribution of the structures were recorded. The structures were separated into two types: simple and complex, both located in high terrain. Simple structures are shorter than complex ones and are built when animals are in search of food or as temporary shelters. Complex structures are built as home burrows. The orientation of the entrances of both kinds of burrows is related to the prevalent wind direction.

Dense-sampling reveals a complex distributional pattern between the southernmost marsupials Lestodelphys and Thylamys in Patagonia, Argentina

Abstract Lestodelphys halli and Thylamys pallidior are southernmost representatives of the Order Didelphimorphia. We analyzed their southern distribution compiling locality records south of 42°S (Chubut and Santa Cruz provinces). We found 87 locality records for L. halli and 105 for T. pallidior. The distribution of L. halli reaches the central plateaus of Santa Cruz province but avoids the northeastern corner of the Deseado Massif. We report the southernmost locality for this species. The eastern and southern distribution of T. pallidior follows the courses of major rivers and coastal areas and it was not found at altitudes >700 m. Its southern distribution is more reduced than in L. halli, not reaching latitudes south of 46°S. We have recorded 20 localities of sympatry between both taxa, all of them from owl pellet samples; however, we have not found conclusive evidence of syntopy by trapping at any site. Both marsupials have widespread distribution in south-central Patagonia with two different histories: one, that of L. halli, related to Patagonian steppes and the other one linked to arid and semiarid lowlands represented by T. pallidior.

New data on the endemic Patagonian long-clawed mouse Notiomys edwardsii (Rodentia: Cricetidae)

Abstract The monotypic Notiomys is the most poorly-known genus of Abrotrichini, a recently erected tribe of South American sigmodontine rodents. Based on a large sample, mostly recovered from owl pellets but including trapped individuals, we refine the known geographic distribution of this mouse (providing 20 new contemporary recording localities and four fossil occurrences), relate this to the principal Patagonian environmental units, add new data on the type locality of the species, and comment on its conservation status. In addition, we present a detailed external and craniodental description and provide data showing geographic variation of some skull features. Finally, we provide preliminary data on genetic variation (cytochrome b gene sequences) that demonstrate the existence of a low degree of observed differentiation (ca. 0.7%) between the populations analyzed.

Discovery of desert-adapted Tympanoctomys barrerae in Central Patagonia, Argentina

No abstract available

Mammalia, Didelphimorphia and Rodentia, southwest of the province of Mendoza, Argentina

We documented terrestrial micromammal assemblages at five localities of southwestern Mendoza province, Argentina. We added new localities for several of the most uncommon small mammal species of this region (e.g. Loxodontomys micropus and Tympanoctomys barrerae). Two main groups of terrestrial non-volant micromammals are represented in southwestern province of Mendoza: one group is related to the South American arid diagonal, and includes species typically adapted to the xeric environments of the Monte Desert; a second group includes Patagonian and High Andean species. Some Patagonian species reached in the study area their northernmost distributional records (e.g. Abrothrix longipilis, A. olivaceus, Chelemys macronyx, Loxodontomys micropus).

Mammalia, Rodentia, Sigmodontinae, Holochilus brasiliensis (Desmarest, 1819): distribution extention

We report the southernmost record for the marsh rats Holochilus brasiliensis 20 km S of Pedro Luro on Hwy 3, province of Buenos Aires, Argentina (39°41’31.13”S, 62°40’23.5”W) extending the range of the species ca. 110 km S. This represents the first contemporaneous record of H. brasiliensis in Patagonia, and also the only species of sigmodontine rodent with amphibious habits reported in Patagonia.

Observations on the captive behavior of the rare Patagonian opossum Lestodelphys halli (Thomas, 1921) (Marsupialia, Didelphimorphia, Didelphidae)

Abstract We describe the behavior in captivity of the rare Patagonian opossum (Lestodelphys halli) from five individuals captured at three localities, which were kept alive in glass terraria for different periods of time (between 2.5–3.5 months). During our observations we found that L. halli can climb and jump well, has a prehensile tail-tip which can hold the body suspended for several seconds, powerful grasping hind feet and the ability to dig. Feeding preferences of meat (mainly raw) and live animals (i.e., mice, lizards and beetles) over vegetables or fruit was observed. We document the first records of torpor/hibernation for the species, its locomotion and exploration patterns and feeding postures. Resting/sleeping in L. halli is done with the body curled along a vertical axis and its head placed against the chest and between the hind legs, a posture different from previously reported American marsupials. Stereotyped behavior patterns (e.g., grooming) were observed and compared with other studied species, providing comparative information for further studies on New World marsupials.

New Data on Armadillos (Xenarthra: Dasypodidae) for Central Patagonia, Argentina

Abstract Armadillos represent the most diverse family of xenarthrans. Although many studies have been done on these mammals, several topics, such as their local distribution, natural history, behavioral ecology and conservation, remain poorly known. Chaetophractus villosus and Zaedyus pichiy are the most common armadillos in extra-Andean Patagonia, a vast area in southern Argentina and Chile that encompasses different ecosystems and has been modified by human activities, mainly by sheep grazing. In this work we present new data on the distribution, natural history, conservation, and ecology of C. villosus and Z. pichiy from central Patagonia (Chubut and Río Negro provinces, Argentina). We registered 60 localities for C. villosus and 35 for Z. pichiy that confirm their presence in wide sectors of central Patagonia. Furthermore, we confirmed that these two armadillo species suffer high rates of mortality due to their use as a protein source, hunting by dogs, road traffic, and poisoning, among others. We conclude that their populations are at risk of overexploitation and local extinction. The basic knowledge provided here will be a first step towards the conservation of these characteristic Patagonian mammals.

Bats at the end of the world: new distributional data and fossil records from Patagonia, Argentina

Abstract We report new recent and fossil records in Patagonia for six and three bat species, respectively. These findings significantly increase the previously known number of localities for these mammals in this entire region, filling gaps between previous references for some species (e.g., Histiotus macrotus) and/or extending by 140–350 km the range of others (e.g., Myotis chiloensis, M. levis, Lasiurus varius). In addition, we report for the second time the vespertilionid bat Lasiurus blossevillii in Patagonia. Fossils are mostly restricted to the Late Holocene epoch, and the recorded assemblages are similar to the recent ones. A preliminary analysis of richness indicates that bat diversity south of the Colorado River (around 39°S) decreases from five to six species in the northwestern to one species in the southeastern, changing abruptly around 43°S–46°S. Compared with similar latitudes of the Northern Hemisphere, bat diversity in the Neotropics follows a similar pattern, with <20 taxa occurring south of 35°S.

Enlarging the knowledge on Graomys griseoflavus (Rodentia: Sigmodontinae) in Patagonia: distribution and environments

No abstract available