Maria Rita Silvério Pires

The genus Abrawayaomys Cunha and Cruz, 1979 (Rodentia: Cricetidae: Sigmodontinae): geographic variation and species definition

Abrawayaomys is a genus endemic to the Atlantic Forest with unique craniodental attributes within the radiation of sigmodontine rodents. Recent data hypothesized the existence of 2 species of Abrawayaomys, namely A. ruschii (from the Brazilian states of Espírito Santo, Rio de Janeiro, and São Paulo) and A. chebezi (from the Argentinean province of Misiones and the Brazilian state of Paraná), as well as a possible undescribed species (from the Brazilian state of Minas Gerais). Herein, based on a large series of recently collected specimens, we assessed the congruence between morphologic and molecular characters to search for discontinuities on these features across geography to delimit species within the genus, testing the aforementioned hypothesis. Morphological analyses, both qualitative and quantitative, showed that all characters are polymorphic throughout the geographic range of the genus. Results from phylogenetic analyses of cytochrome b (Cytb) data showed the topology (Misiones (Minas Gerais (São Paulo, Rio de Janeiro))), which is better explained as geographic rather than taxonomic variation, based on low values of genetic divergence observed between all specimens. Therefore, we reject the hypothesis of a polytypic Abrawayaomys, synonymizing A. chebezi to A. ruschii, and do not recognize specimens from Minas Gerais state as representing a distinct species.

Effects of cornfields on small mammal communities: a test in the Atlantic Forest hotspot

Croplands have expanded dramatically during the last century, frequently leading to severe biodiversity losses within occupied areas. In addition to such direct influences, croplands may also have affected biodiversity within adjacent natural habitats, yet such potential indirect effects have rarely been quantified. Here, we test for effects of cornfields on small mammal communities inhabiting forest fragments in the Atlantic Forest biodiversity hotspot, Brazil. We test the hypotheses that cornfields increase the abundance and dominance of granivorous small mammals in adjacent forest fragments but reduce the abundance of nongranivorous species and community richness. To test these hypotheses, we used a replicated randomized block design, comparing communities located at forest interiors, forest-cornfield edges, and also forest-road edges. The abundance of granivorous small mammals was significantly higher at forest-cornfield edges compared to the other treatments, whereas insectivorous—omnivorous species had an apparently neutral response to the edges. Forest-cornfield edges harbored fewer small mammal species and tended to have a greater dominance of granivores. Forestcornfield and forest-road edges harbored species characteristic of both forested and nonforested habitats. Our findings suggest that cornfields alter the structure of native small mammal communities, mostly by providing complementary resources for granivores.

Lizard fauna (Squamata, Sauria) from Serra do Ouro Branco, southern Espinhaço Range, Minas Gerais, Brazil

The present study evaluated the lizard fauna in Serra do Ouro Branco, Minas Gerais, Brazil, a transition area between the Atlantic Forest and Cerrado. Data was collected using pitfall traps, active and occasional encounters, and through information from zoological collections and the literature. Field sampling was performed in two stages over a period of 36 months: from December 2006 to December 2008, and from January to December 2010. The study area is home to 15 species belonging to eight families: Anguidae, Gekkonidae, Gymnophthalmidae, Leiosauridae, Polychrotidae, Mabuyidae, Teiidae, and Tropiduridae. Lizard species evaluated in this study represent a relevant asset for this zoological group inhabiting the transitional areas between the Atlantic Forest and Cerrado. They include strictly forest species and endemic Atlantic Forest species such as Ecpleopus gaudichaudii , Enyalius perditus and Heterodactylus imbricatus in addition to typical Cerrado taxa common to both biomes.

Riqueza e densidade de aves que nidificam em cavidades em plantações abandonadas de eucalipto

Monoculturas de arvores, como as de especies de eucalipto, tem substituido florestas naturais, impactando a fauna pela perda de habitat e recursos. Diversas especies de aves necessitam de ocos em arvores para nidificar. A falta de recursos como cavidades formadas pela degradacao da arvore ou locais apropriados para serem criadas cavidades leva a diminuicao na abundância das populacoes destas especies. Este trabalho tem o objetivo de comparar a riqueza e a densidade de aves que nidificam em ocos em areas de plantacao de eucalipto abandonadas com areas de vegetacao nativa em duas unidades de conservacao em Minas Gerais. Em cada tipo de vegetacao de cada reserva foram estabelecidos 25 pontos, nas quais foi utilizado o metodo de contagem por remocao para o levantamento das especies de aves. A riqueza de especies de aves de cada area foi estimada por Jackniffe e a densidade foi estimada atraves do metodo de maxima verossimilhanca; modelos candidatos que poderiam influenciar a abundância das aves foram avaliados utilizando-se o Criterio de Informacao Akaike (AIC). Os resultados mostraram que a riqueza de especies foi maior nas areas de florestas nativas e que a densidade foi significantemente mais alta nas areas de florestas nativas, e que o tipo de vegetacao e a hora do dia influenciam na abundância e deteccao das aves. Esses resultados indicam que as plantacoes de eucaliptos influenciam negativamente a comunidade de aves que nidificam em ocos, provavelmente por causa da falta de cavidades ou de sub-bosque. Plantacoes de eucaliptos normalmente nao substituem as florestas nativas e seu uso deve ser controlado em areas de conservacao.

New distribution reports of Rhagomys rufescens (Rodentia: Sigmodontinae) Thomas, 1886

Rhagomys rufescens is a rare, arboreal sigmodontine rodent endemic to the Brazilian Atlantic Forest biome. This species is known from eight localities in Brazil. Here we present a new report based on four individuals of this species registered in Serra do Ouro Branco, municipality of Ouro Branco (Minas Gerais, Brazil). One juvenile male, one adult male and two juvenile females were captured in pitfall traps during the rainy season, in a study of small mammal ecology. This is the first record for the Espinhaco Mountain range and the northernmost report for the species in this state, 85 km northeast of the last registered location.