Lena Geise

Pattern of elevational distribution and richness of non volant mammals in Itatiaia National Park and its surroundings, in Southeastern Brazil

Itatiaia National Park (PNI) and its surroundings present a unique fauna due to different forest formations with well-defined climatic and vegetation bands. The Itatiaia massif has four vegetation types that follow an altitudinal gradient: lower montane forest, montane forest, upper montane forest, and Campos de Altitude. Hence, this region is ideal for studying geographical variation in biological diversity. The main objectives of this study were to report on nonvolant mammal species known to occur in Itatiaia National Park and its surroundings and to determine if their distributional pattern is related to elevation. A review of the literature and a complete survey of specimens deposited in museums, as well as small-mammal trapping were carried out in order to obtain a complete record of the species from the region. Precise locality data were obtained for all specimens recorded, allowing the inclusion of each collected or observed individual in an altitude and vegetational class. We made a direct ordination gradient of marsupial, primate, and rodent species abundance with the altitude. Sixty-nine mammal species were collected or reported for the Itatiaia massif, belonging to seven orders and 20 families. Of these, 33 species (47.8%) are included in the official list of threatened or believed-to-be threatened species in Rio de Janeiro State. The orders Rodentia, Carnivora, and Didelphimorphia had the highest species richness, with 25, 14, and 13 species respectively. When species were grouped according to the vegetation, 16 species occured in the lower montane, 56 in the montane forest, five in the upper montane, and 21 in the high-altitude fields (Campos de Altitude). The communities of marsupials, primates, and rodents have an ordination pattern related to the altitude. Species richness was higher between 500 m and 1,500 m above sea level in montane forest, which is in agreement with recent studies showing that species richness can reach its maximum at mid-elevations.

Diversification in the genus Akodon (Rodentia : Sigmodontinae) in southeastern south America : Mitochondrial dna sequence analysis

Abstract Phylogenetic relationships of 6 species of the genus Akodon have been determined by mtDNA sequence analysis of the cytochrome-b gene, with the majority of specimens also identified by karyotype. We used maximum parsimony and distance analyses of 54 sequences to assess phylogenetic relationships and minimum spanning trees to compare genetic and geographic relationships among populations. The genus Bolomys was used as the outgroup. Akodon cursor, A. aff. cursor, and A. montensis, 3 morphologically cryptic but karyotypically different species of the cursor complex, each formed reciprocally monophyletic lineages. Twenty-one haplotypes were present in 23 individuals of A. cursor, and each of the 16 specimens of A. montensis had a unique haplotype. Within species, populations of A. cursor (19 localities) showed high variation with little geographic pattern. Distant populations (∼750 km apart, differing by 12 nucleotides) exhibited similar levels of differentiation as did geographically close populations (∼150 km apart, differing by 17 nucleotides). In contrast, A. montensis (12 localities) was structured geographically and exhibited a pattern consistent with an isolation-by-distance model of differentiation. Among other species in southeastern Brazil, A. mystax was related most closely to the cursor species complex, A. lindberghi was somewhat more distant, and A. serrensis was quite distinct.

Mammals of Serra da Bocaina National Park, state of Rio de Janeiro, southeastern Brazil

Here we present a commented list of mammals registered in the Serra da Bocaina National Park. Three field trips (February, 2010, and May and July, 2011) were accomplished along the RJ-165 highway in the Municipality of Paraty, State of Rio de Janeiro, Brazil. Forty-eight species belonging to nine orders were recorded. The local mammal fauna could be considered diverse and rich, with some species regarded as biological indicators of habitat quality. Endangered and rare rodent species like Blarinomys breviceps , Juliomys rimofrons , and Thaptomys nigrita were captured. Road and hunting impacts on mammals are discussed.

Colonization Process of the Brazilian Common Vesper Mouse, Calomys expulsus (Cricetidae, Sigmodontinae): A Biogeographic Hypothesis

Riverine barriers have been associated to genetic diversification and speciation of several taxa. The Rio São Francisco is one of the largest rivers in South America, representing the third largest river basin in Brazil and operating as a geographic barrier to gene flow of different taxa. To evaluate the influence of the Rio São Francisco in the speciation of small rodents, we investigated the genetic structure of Calomys expulsus with phylogenetic and network analyses of cytochrome b DNA. Our results suggested that C. expulsus can be divided into 3 subpopulations, 2 on the left and another one on the right bank of this river. The time of divergence of these subpopulations, using a Bayesian framework, suggested colonization from the south to the north/northeast. Spatial analysis using a clustering method and the Monmoniers algorithm suggested that the Rio São Francisco is a biogeographic barrier to gene flow and indicated that this river may play a role in the incipient speciation process of these subpopulations.

Non-flying mammals of Chapada Diamantina (Bahia, Brazil)

Chapada Diamantina is located in central Bahia state, and has a large diversity of habitats, including important transitional areas, but has remained largely unstudied until now. In the present study we list the non-flying mammals of Chapada Diamantina National Park and surroundings. We captured only small non-volant mammals, medium and large mammals were assessed through indirect evidences (tracks and marks) and interviews. We recorded 58 species and 47 genera from seven Mammalian orders. Seven species are included in the list of endangered Brazilian species by IBAMA and IUCN; and other seven are classified as data-deficient. Species richness of small mammals was equivalent among sampled habitats, but species composition varied among habitats (10 in semi-deciduous forest, 9 in rocky savanna and 8 in cerrado sensu stricto), as some species are restricted by humidity to forest habitats. During four different samplings, eight species were collected only in open vegetation, four only in forests, and six in both habitats. Oligoryzomys rupestris and Gracilinanus microtarsus had its geographic range expanded. Faunal composition is similar to the one observed in the Atlantic Forest, including species from Cerrado and Caatinga. Besides, some species occupy different habitats from those previously ascribed to them.

Karyotype composition of some rodents and marsupials from Chapada Diamantina (Bahia, Brasil)

The Chapada Diamantina (CD) is located in Bahia State, between 11-14 degrees S and 41-43 degrees W, being part of the Serra do Espinhaço. The occurrence of different habitats and transition areas permits an interesting mammal fauna composition, with species from different biomes living in sympatry. Species of Didelphimorphia and Rodentia are important members of mammal communities in almost all different habitats, and morphological and cytogenetic characters are important for a correct identification of most of these species. In this work 258 specimens of small mammals from the orders Didelphimorphia (six genera and six species) and Rodentia (two families, five Sigmodontinae tribes, nine genera and 11 species) were collected during the whole field work (44 nights with traps). Chromosome preparations were obtained from 145 specimens from the species: Marmosops incanus, Gracilinanus microtarsus, Monodelphis domestica, Akodon aff. cursor, Necromys lasiurus, Cerradomys sp., Oligoryzomys fornesi, O. nigripes, O. rupestris, Calomys expulsus, Rhipidomys macrurus, Wiedomys pyrrhorhinus and Thrichomys inermis. Didelphis albiventris, Micoureus demerarae, Thylamys karymii and Nectomys sp. were identified by morphological characters. Most analyzed specimens do not show karyotype variation. However, numerical chromosomic variation was found in two individuals of Akodon aff. cursor (2n = 15) and in one individual of Cerradomys sp. (2n = 51). Structural variation in karyotype was observed in seven individuals of Cerradomys sp., showing one additional pair of metacentric chromosomes.

Phylogeographic Structure and Karyotypic Diversity of the Brazilian Shrew Mouse (Blarinomys breviceps, Sigmodontinae) in the Atlantic Forest

Blarinomys breviceps possesses cryptic and burrowing habits with poorly documented genetics and life history traits. Due to its rarity, only a few specimens and DNA sequences have been deposited in collections worldwide. Here, we present the most comprehensive cytogenetic and molecular characterization of this rare genus. Phylogenetic analyses based on partial cytochrome b sequences were performed, attempting to establish the relationships among individuals with distinct karyotypes along the geographic distribution of the genus in the Atlantic Forest. Classical and molecular cytogenetics, using banding patterns and FISH of telomeric and whole chromosome X-specific painting probes (obtained from the Akodontini Akodon cursor) were used to characterize and compare the chromosomal complements. Molecular phylogenetic analyses recovered 2 main geographically structured clades, northeastern and southeastern with pairwise sequence divergences among specimens varying between 4.9 and 8.4%. Eight distinct karyomorphs are described: (A) 2n = 52 (50A, XX), (B) 2n = 52 (48A, XY+2Bs), (C) 2n = 45 (42A, XY+1B), (D) 2n = 43 (37A, XX+4Bs), (E) 2n = 37 (34A, XY+1B), (F) 2n = 34 (32A, XX), (G) 2n = 31 (27A, XX+2Bs), (H) 2n = 28 (26A, XY), all with the same number of autosomal arms (FNA = 50). Variation of 0–4 supernumerary chromosomes (Bs) presenting heterogeneity in morphology and distribution of interstitial telomeric sequences (ITSs) is reported. ITSs are also found in some metacentric autosomes. The phylogeographic separation between 2 major lineages with high levels of genetic divergence, and the wide karyotypic diversity indicate that B. breviceps is a diverse group that warrants taxonomic re-evaluation.

Non-volant mammals, Parque Nacional do Catimbau, Vale do Catimbau, Buíque, state of Pernambuco, Brazil, with karyologic data

We report the results of a terrestrial small mammal survey at one National Park in the northeastern Brazil, in the state of Pernambuco. The Catimbau National Park is located within the Caatinga domain with the characteristic thorn scrub vegetation. Our sampling encompasses several different vegetation/habitat types within the park area. All specimens collected were prepared as vouchers to be deposited in the Museu de Zoologia da Universidade de Sao Paulo. Karyotypes were obtained for all representative purported species collected. We report here the results of this first survey – two species of marsupials and seven of rodents - and added new occurrence localities for several small mammal species of this region, provide karyotypic information and register an undescribed species of arboreal rat of the genus Rhipidomys . This survey illustrates the need for extensive and planned sampling of the Caatinga domain.

The phylogenetic position of the enigmatic Atlantic forest-endemic spiny mouse Abrawayaomys (Rodentia: Sigmodontinae)

BackgroundThe phylogenetic position of the sigmodontine genus Abrawayaomys, historically assigned to the tribe Thomasomyini or considered a sigmodontine incertae sedis, was assessed on the basis of nuclear and mitochondrial DNA sequences obtained from four individuals from different localities in the Atlantic forest of Brazil. Sequences of Abrawayaomys were analyzed in the context of broad taxonomic matrices by means of maximum-likelihood (ML) and Bayesian analyses (BA).ResultsThe phylogenetic position of Abrawayaomys differed depending on the gene analyzed and the analysis performed (interphotoreceptor retinoid-binding protein (IRBP) ML: sister to Thomasomyini; IRBP BA: sister to Akodontini; cytochrome (Cyt) b ML: sister to Neotomys; and Cyt b BA: sister to Reithrodontini). With the sole exception of the BA based on Cyt b sequences, where the Abrawayaomys-Reithrodon clade had strong support, all sister-group relationships involving Abrawayaomys lacked any significant support.ConclusionsAs such, Abrawayaomys constitutes the only representative so far known of one of the main lineages of the sigmodontine radiation, differing from all other Atlantic forest sigmodontine rodents by having a unique combination of morphological character states. Therefore, in formal classifications, it should be regarded as a Sigmodontinae incertae sedis.

Prediction of threatened tetrapods based on the species–area relationship in Atlantic Forest, Brazil

The species–area relationship was used to test the effects of habitat reduction on the proportion of tetrapod species that would be considered threatened with extinction, assuming the current estimate of 19% of remaining forest coverage in Rio de Janeiro State, Brazil. Here, species–area estimates from deforestation were compared with a Red List produced by experts. Analyses were performed with: (1) the total pool of species that occur in Rio de Janeiro State (159 amphibians, 115 reptiles, 635 birds and 157 mammals); (2) the pool of species endemic to the Atlantic forest (109 amphibians, 46 reptiles, 149 birds and 35 mammals). The sensitivity of the analyses to variations in the Z parameter of the species–area relationship was evaluated. In general, the species–area overestimated the total number of species threatened with extinction for all tetrapods, while the estimate of endemic mammals predicted to be extinct was close to the number of endemic species listed as threatened with extinction. Furthermore, changes in the Z-values did not affect those results. The species–area relationship accurately predicted the number of endemic birds assumed to be extinct since it used values of Z smaller than 0.25. The analyses with endemic species of reptiles and amphibians of Atlantic forest overestimated the number of species predicted to be extinct for both groups. In conclusion, at the considered scale, mammals and birds endemic to the Atlantic forest seem to be more affected by deforestation than reptiles and amphibians.