519.

Atlantic Forest Burrowing Mouse

Blarinomys breviceps

French: Akodon musaraigne / German: Brasilianische Spitzmausratte / Spanish: Raton cavador de bosque atlantico

Other common names: Blarinine Akodont, Brazilian Shrew Mouse

Taxonomy. Oxymycterus breviceps Winge, 1887, Pleistocene cave deposits (Lapa do Capao Seco) near Lagoa Santa, Minas Gerais, Brazil.

Holotype of Blarinomys breviceps is a fossil recovered in a cave assemblage of undetermined Quaternary age. Blarinomys breviceps is the type species of the genus. Important morphological, chromosomal (including up to date eight distinct karyomorphs), and mtDNA cytochrome-b sequence variations (with intraspecific divergences c¢.8%) are displayed in recent populations. Monotypic.

Distribution. E & SE Brazil and NE Argentina (Misiones Province).

Descriptive notes. Head-body 91-121 mm, tail 30-59 mm, ear 7-10 mm, hindfoot 16-21 mm; weight 12-5-49 g. Females are slightly larger than males. The Atlantic Forest Burrowing Mouse is a small akodontlike sigmodontine, characterized by overall resemblance to species of Talpidae . Body is fusiform, with short and conical head, extremely reduced eyes hidden in fur, very small and well-haired pinnae, and short, unicolored, and sparsely haired tail (usually less than 50% of head-body length). Pelage 1s short, crisp, velvety, and more or less uniformly dark slate-gray throughout, with reddish or brownish hair tips. Dorsum is slightly iridescent, with ruby tinge. Underparts are gray-brown, scarcely differentiated from dorsum. Tip of muzzle and chin are whitish. Manus has long pointed claws and strongly reduced fifth digit. Pes has short and curved claws. Hands and feet are brown above. Palms and soles of feet are naked, except for heel.

Habitat. Primary and secondary Atlantic Forests, moderately disturbed habitats such as forest fragments in agricultural areas, and grasslands near tops of hilly areas (“campos de altitude”). The Atlantic Forest Burrowing Mouse is primarily an Atlantic Forest dweller, but a few records are from transitions between it and Cerrado biome.

Food and Feeding. Some Atlantic Forest Burrowing Mice were captured with snap traps baited with corn and placed in leaflitter, but most specimens have been obtained in pitfall buckets or recovered from owl pellets. Diet consists primarily of invertebrates, with stomachs containing arthropods from six different orders, mostly insects, but also arachnids. Captive individuals were docile and accepted a wide variety of insects, mainly orthopterans, roaches, and lepidopteran pupae and larvae, but they refused fruit and seeds, except from oranges. Insects were caught using hands and manipulated for easy ingestion. Stable isotope values in Atlantic Forest Burrowing Mice had relatively high 615N levels, suggesting animal prey and fungi as important food sources.

Breeding. Male Atlantic Forest Burrowing Mice with scrotal testes were collected in January-February; pregnant females were trapped in September and January—February, suggesting in spring-summer breeding season. Litters had 1-2 young.

Activity patterns. Body plan of the Atlantic Forest Burrowing Mouse has been considered a suitable example of a fossorial cricetid specialized to a morphotype convergent with soricines or talpines. They use galleries under leaf litter at depths up to 25 cm and captive individuals excavated shallow burrows. Diurnal activity was reported for a hand-caught individual in a sunny day when it was moving from a thicket of bamboo.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Nevertheless, the Atlantic Forest Burrowing Mouse seems to be part of the wet-forest community that is no longer found in the region of Lagoa Santa, suggesting recent extirpation.

Bibliography. Abravaya & Matson (1975), de Avila-Pires (1960a), de Avila-Pires & Gouvéa (1977), Davis, D.E. (1944), Dias (2016), Didrio et al. (2011), Fagundes & Costa (2009), Fagundes et al. (2009), Galetti et al. (2016), Geise, Bergallo et al. (2008), Geise, Pereira et al. (2004), Goeldi (1902), Granzinolli & Motta-Junior (2006), Gudinho & lack-Ximenes (2010), Hershkovitz (1966a), Machado et al. (2016), Matson & Abravaya (1977), Oehimeyer et al. (2010), Paglia, De Marco et al. (1995), Paglia, Perini et al. (2005), Pardinas, Patterson et al. (2016b), Pardini (2004), Pereira et al. (2010), dos Reis et al. (1996), Silva et al. (2003), Teta & Pardinas (2015c), Thomas (1896b), Ventura et al. (2012), Winge (1887).