Systematic Review of Genus Cerradomys Weksler, Percequillo and Voss, 2006 (Rodentia: Cricetidae: Sigmodontinae: Oryzomyini), with Description of Two New Species from Eastern Brazil

Species limits and recent diversification of Cerradomys (Sigmodontinae: Oryzomyini) during the Pleistocene

Cerradomys is a genus of the tribe Oryzomyini with eight species currently recognized, and a controversial taxonomy. These species are mainly distributed in the South America dry diagonal, but some species extend into Atlantic Forest, reaching the coastal sandy plains known as Restingas. This study aimed to address species limits and patterns of diversification of Cerradomys species. For this purpose, we performed cytogenetic and molecular analyses (phylogeny, coalescent species delimitation, barcoding, and divergence times estimation) using multiple mitochondrial and nuclear markers on a comprehensive sampling, representing all nominal taxa reported so far. Chromosomal information was a robust marker recognizing eight Cerradomys species. Reciprocal monophyly was recovered for all the species, except for C. subflavus. These results together with coalescent analyses recovered eight species as the most congruent species delimitation scenario for the genus (mean C _tax : 0.72). Divergence time estimates revealed that Cerradomys' diversification occurred about 1.32 million years ago (Mya) during the Pleistocene. Although our results conservatively support the eight Cerradomys species described so far, different lines of evidence suggest that C. langguthi and C. subflavus could potentially be species-complexes. We discussed this scenario in the light of multiple evolutionary processes within and between species and populations, since Cerradomys comprises a species group with recent diversification affected by Pleistocene climatic changes and by the complex biogeographic history of South America dry diagonal. This work supports that the diversity of Cerradomys is underestimated and reiterates that interdisciplinary approaches are mandatory to identify small rodent species properly, and to unhide cryptic species.

Habitat Heterogeneity and Geographic Location as Major Drivers of Cerrado Small Mammal Diversity Across Multiple Spatial Scales

The Cerrado biome is one of the global hotspots of biodiversity, and non-volant small mammals represent a significant portion of Cerrado species richness (45%) and endemism (86%). Nevertheless, we still lack a comprehensive picture of small mammal diversity patterns and drivers throughout the Cerrado. Here we surveyed small mammals across 45 sites to address species richness, abundance, and composition patterns and their drivers within and across sites, habitats, and localities at the world’s most diverse tropical savanna. As hypothesized, we found: (1) rich assemblages (12–21 species) characterized by few abundant and several intermediate-level and rare species; dominated by oryzomyine and akodontine cricetid rodents, and thylamyine and marmosine within marsupials, each tribe showing distinct habitat requirements; (2) strong habitat selectivity, with assemblages composed of forest dwellers, savanna specialists, and grassland inhabitants; and (3) similar species richness (α-diversity) but high species turnover (β-diversity) across sites, habitats, and localities, suggesting that horizontal stratification (within localities) and geographic location (across the Cerrado) are key drivers of small mammal diversity in tropical savannas. Thus, habitat heterogeneity and geographic location can be inferred as the main factors shaping species richness, abundance, and composition across the analyzed multiple spatial scales. Moreover, we found that geographical distance as well as the distance to neighbor biomes better explained species turnover, indicating landscape history and phylogenetic constraints as the major determinants of Cerrado small mammal diversity, as also evidenced for plants and other animal groups. These data highlight the need to preserve the mosaic of habitats across the different regions of the biome to conserve most of the Cerrado biodiversity.

Areas of endemism of small mammals are underprotected in the Atlantic Forest

Atlantic Forest (AF) is amongst the most threatened forests in the world. To decide where conservation efforts should be focused to preserve species, assessment of ecological and biogeographic processes nowadays are crucial. Patterns of the distribution of organisms can provide an important source of information underlying the biogeographical history of a biota. Here, our main objective was to identify Areas of Endemism (AoE) for non-volant small mammals in the AF and to investigate if those AoE are covered by protected areas. We performed quantitative and qualitative approaches to delimit AoE and calculated the area overlaid by Conservation Units (CU) within each AoE. Our results supported the recognition of seven AoE for small mammals in the AF, which largely are congruent with previous studies undertaken on other organisms, thereby highlighting the importance of those regions as hotspots of endemism. Most of the AoE recovered in the present study have less than 12% of their territory covered by forest remnants, and less than 11% of their entire range is under legal protection. These findings bring to light an important discussion on how information pertaining to the representativeness of CU within regions of high endemicity could help to identify areas in need of urgent protection within a threatened biodiversity hotspot.

A new species of South America marsh rat (Holochilus, Cricetidae) from northeastern Brazil

Marsh rats of the genus Holochilus are broadly distributed and inhabit several distinct environments throughout South America. As an enigmatic group with a somewhat uncertain taxonomy, the composition and names of taxa have shifted throughout history, including the boundaries of Holochilus sciureus, a species formerly distributed in the lowlands of the Guianas, Peru, Bolivia, and northern, central, and northeastern of Brazil. Based on a combination of morphological and morphometric traits, and genomic sequences, we redefined species boundaries and split this wide concept of H. sciureus into three separated species, including a redefined H. sciureus, the newly erected from synonymy H. nanus, and an unnamed taxon. We describe this unnamed species, and provide emended diagnoses for the two redefined species. The newly named taxon inhabits the northeastern part of Brazil and differs from the other congeners by a unique combination of phenotypic and genomic characters.

A new species of Akodon Meyen, 1833 (Rodentia: Cricetidae: Sigmodontinae) endemic from the Brazilian Cerrado

Akodon is the second most diverse genus of sigmodontine rodents, comprising 40 extant species. Widely distributed through different environments of South America, the genus ranges from forested to open-vegetation areas, from semiarid to mesic regions, and from Andean altitudes to the lowlands of eastern Brazil. In Brazil, most species are from the Atlantic Forest, inhabiting lowland and montane habitats, with a few taxa also present in areas transitional with the Cerrado and Pantanal. Based on an integrative approach of genetics (cytogenetic and molecular data) and morphology (qualitative and quantitative external and craniodental data), we present in this contribution the hypothesis of a new species of Akodon based on specimens collected in the southwestern limit of the Cerrado domain, in the seasonally dry forests of the Serra da Bodoquena, Mato Grosso do Sul, Brazil. The new species was recovered as a distinct lineage sister to Akodon philipmyersi, a poorly known species from the Northern Campos grasslands of Misiones Province, Argentina, and can be distinguished from its congeners by its karyotype (2n = 40, FN = 40), morphology (morphometric, pelage, and skull characters), as well as by its degree of genetic divergence (above 7.5% in Cytb sequences). This new species is endemic to the Cerrado, one of the world’s biodiversity hotspots, and to Serra da Bodoquena, one of the top priority areas for conservation in Brazil. Moreover, the new species increases the number of lineages of Akodon in Brazil, emphasizing the richness and endemism currently found in the Cerrado domain, and the importance of the open formations to the diversification of Neotropical taxa.

Tempo and mode of evolution of oryzomyine rodents (Rodentia, Cricetidae, Sigmodontinae): A phylogenomic approach

The tribe Oryzomyini is an impressive group of rodents, comprising 30 extant genera and an estimated 147 species. Recent remarkable advances in the understanding of the diversity, taxonomy and systematics of the tribe have mostly derived from analyses of single or few genetic markers. However, the evolutionary history and biogeography of Oryzomyini, its origin and diversification across the Neotropics, remain unrevealed. Here we use a multi-locus dataset (over 400 loci) obtained through anchored phylogenomics to provide a genome-wide phylogenetic hypothesis for Oryzomyini and to investigate the tempo and mode of its evolution. Species tree and supermatrix analyses produced topologies with strong support for most branches, with all genera confirmed as monophyletic, a result that previous studies failed to obtain. Our analyses also corroborated the monophyly and phylogenetic relationship of three main clades of Oryzomyini (B, C and D). The origin of the tribe is estimated to be in the Miocene (8.93-5.38 million years ago). The cladogenetic events leading to the four main clades occurred during the late Miocene and early Pliocene and most speciation events in the Pleistocene. Geographic range estimates suggested an east of Andes origin for the ancestor of oryzomyines, most likely in the Boreal Brazilian region, which includes the north bank of Rio Amazonas and the Guiana Shield. Oryzomyini rodents are an autochthonous South America radiation, that colonized areas and dominions of this continent mainly by dispersal events. The evolutionary history of the tribe is deeply associated with the Andean cordillera and the landscape history of Amazon basin.

Extensive genomic reshuffling involved in the karyotype evolution of genus Cerradomys (Rodentia: Sigmodontinae: Oryzomyini)

Rodents of the genus Cerradomys belong to the tribe Oryzomyini and present high chromosome variability with diploid numbers ranging from 2n=46 to 60. Classical cytogenetics and fluorescence in situ hybridization (FISH) with telomeric and whole chromosome-specific probes of another Oryzomyini, Oligoryzomys moojeni (OMO), were used to assess the karyotype evolution of the genus. Results were integrated into a molecular phylogeny to infer the hypothetical direction of chromosome changes. The telomeric FISH showed signals in telomeres in species that diverged early in the phylogeny, plus interstitial telomeric signals (ITS) in some species from the most derived clades (C. langguthi,C. vivoi, C. goytaca, and C. subflavus). Chromosome painting revealed homology from 23 segments of C. maracajuensis and C. marinhus to 32 of C. vivoi. Extensive chromosome reorganization was responsible for karyotypic differences in closely related species. Major drivers for genomic reshuffling were in tandem and centric fusion, fission, paracentric and pericentric inversions or centromere repositioning. Chromosome evolution was associated with an increase and decrease in diploid number in different lineages and ITS indicate remnants of ancient telomeres. Cytogenetics results corroborates that C. goytaca is not a junior synonym of C. subflavus since the karyotypic differences found may lead to reproductive isolation.

Tyto furcata (Tytonidae: Strigiformes) pellets: tools to access the richness of small mammals of a poorly known Caatinga area in northeast Brazil

Owls are efficient predators and are widely distributed around the globe. Remains of undigested prey is regurgitated by these birds in the form of pellets, and these are a valuable source of information about prey communities and the diet of owls. In this study, the composition of mammals present in the diet of owls that inhabit different caves was evaluated through the analysis of their pellets. We found 373 pellets from seven caves, and small mammals composed at least 80% of the diet of these birds in all caves. The mammal composition found in the pellets showed a richness of 26 distinct taxa including 12 rodents, three marsupials and 11 bats. In this work, we highlight the richness of small mammals in a poorly known Caatinga area. We also highlight the importance of morphology and taxonomy in supporting this kind of research, which relies upon vertebrate parts as its source of information for identification. Finally, we reiterate the efficiency of the study of owl pellets as a rapid approach for assessing local mammal richness and as a complementary method in studies of diversity and conservation.

Reproduction and growth in a Neotropical arboreal mouse: Oecomys rutilus (Sigmodontinae: Cricetidae) in French Guiana

Abstract: Postnatal growth and development of the small Neotropical mouse Oecomys rutilus (Sigmodontinae: Cricetidae) were investigated from birth to day 143, in the laboratory. Morphometric measurements at age of 3 days, of both sexes combined, revealed body weight to be 3.4 ± 0.3 g, mean tail length as 27.4 ± 1.1 mm, and mean hind foot length as 9.3 ± 0.7 mm. Body weight was found to increase steadily until at least 69 days, whereas the instantaneous growth rates of other measurements declined earlier: the daily growth of hind foot length declined to a minimum at age of 24 days, and the growth of tail and of ear declined by the age of 33 days. Average litter size for 12 captive births was 2.5, ranging from 2 to 3. The preserved eye crystalline lens was weighted in 23 captive-born animals of known age, allowing a rough estimate of the age of reproduction in wild-caught animals. Based on the inferred relation between eye-lens weight and age, the youngest reproductive (pregnant) wild-caught females had an estimated age of 90 and 95 days.

Karyotypes of Brazilian non-volant small mammals (Didelphidae and Rodentia): An online tool for accessing the chromosomal diversity

We have created a database system named CIPEMAB (CItogenética dos PEquenos MAmíferos Brasileiros) to assemble images of the chromosomes of Brazilian small mammals (Rodents and Marsupials). It includes karyotype information, such as diploid number, karyotype features, idiograms, and sexual chromosomes characteristics. CIPEMAB facilitates quick sharing of information on chromosome research among cytogeneticists as well as researchers in other fields. The database contains more than 300 microscopic images, including karyotypic images obtained from 182 species of small mammals from the literature. Researchers can browse the contents of the database online (http://www.citogenetica.ufes.br). The system enables users to locate images of interest by taxa, and to display the document with detailed information on species names, authors, year of the species publication, and karyotypes pictures in different colorations. CIPEMAB has a wide range of applications, such as comparing various karyotypes of Brazilian species and identifying manuscripts of interest.

Description of a new species Physaloptera goytaca n. sp. (Nematoda, Physalopteridae) from Cerradomys goytaca Tavares, Pessôa & Gonçalves, 2011 (Rodentia, Cricetidae) from Brazil

Nematodes of the genus Physaloptera are common in rodents, including in species of the Family Cricetidae. There is no report of nematodes parasitizing Cerradomys goytaca, so this is the first one. For this study, 16 rodents were captured in the city of Quissamã, in the northern of Rio de Janeiro State. The rodents were necropsied, and the digestive tracts were analyzed under a stereomicroscope for the presence of parasites. The nematodes were fixed in hot AFA, clarified in Amann's lactophenol, mounted on slides with coverslip, and observed under an optical microscope. Part of the nematodes was fixed in Karnovisk solution for scanning electron microscopy. Nematodes presented evident sexual dimorphism. Oral openings had two semicircular pseudolabia, with an external lateral tooth and an internal lateral tripartite tooth on each pseudolabium. Males had a ventral spiral curved posterior ends with the presence of a caudal alae with 21 papillae with four pairs of pedunculated papillae arranged laterally, three pre-cloacal sessile papillae arranged rectilinearly and five pairs of post-cloacal sessile papillae. There was also a pair of phasmids located between the fourth and fifth pairs of post-cloacal papillae as well as two spicules that were sub-equal in size but of distinct shapes. The females have five uterine branches. The morphological and morphometrical analyses of the nematodes collected from C. goytaca were compared with other species, and the results indicated that this is a new species of the genus Physaloptera, Physaloptera goytaca n. sp.

Advances in cytogenetics of Brazilian rodents: cytotaxonomy, chromosome evolution and new karyotypic data

Rodents constitute one of the most diversified mammalian orders. Due to the morphological similarity in many of the groups, their taxonomy is controversial. Karyotype information proved to be an important tool for distinguishing some species because some of them are species-specific. Additionally, rodents can be an excellent model for chromosome evolution studies since many rearrangements have been described in this group.This work brings a review of cytogenetic data of Brazilian rodents, with information about diploid and fundamental numbers, polymorphisms, and geographical distribution. We point out that, even with the recent efforts on cytogenetic studies in this group, many species lack karyotypic data. Moreover, we describe for the first time the karyotype of Carterodon sulcidens (Lund, 1838) (Family Echimyidae), a new fundamental number for an undescribed species of Neacomys Thomas, 1900 (Family Cricetidae, Subfamily Sigmodontinae), and illustrate the karyotype of a Brazilian specimen of Mus musculus Linnaeus, 1758 (Family Muridae). This review compiles the cytogenetic data on Brazilian rodents reported in the last three decades, after the last revision published in 1984, including synonyms, chromosomal variations, and geographic distribution. Additionally, it also reinforces that Brazilian biodiversity is still poorly known, considering the new data reported here.

Contrasting the realized and fundamental niche of the arboreal walking performance of neotropical rodents

Evaluation of the fundamental niche under controlled conditions can provide relevant information about physiological, evolutionary, and ecological aspects of an organism, without the influence of external factors. We investigated how allometric, phylogenetic, and adaptive components contribute to arboreal walking performance by 7 sigmodontine rodents of the Brazilian savanna (Cerrado). We captured the rodents in the field and evaluated their performances by measuring stride length, stride frequency, and velocity on 5 horizontal supports: flat board and cylindrical plastic tubes with diameters of 5.0, 3.5, 2.5, and 2.0cm. Arboreal rodents exhibited higher velocities than terrestrial species by increasing stride frequency and decreasing stride length on supports with smaller diameters. However, terrestrial species decreased both stride frequency and stride length or tended to maintain stride length and vary stride frequency. Our results reveal a strong association between realized arboreal walking performances (as inferred by proportion of arboreal captures) and stride length and frequency. However, performance metrics were weakly related to body mass and exhibited no phylogenetic effects. Our results are consistent with the hypothesis that dynamically stable arboreal walking is facilitated by increased velocity. Arboreal walking performance is likely related to ecological factors rather than phylogenetic constraints.

A avaliação do nicho fundamental por meio de condições controladas pode fornecer informações relevantes sobre aspectos fisiológicos, evolutivos e ecológicos de diferentes organismos, excluindo a influência de fatores externos. Considerando tal abordagem, nós investigamos como componentes alométricos, filogenéticos e adaptativos podem contribuir para a habilidade de locomoção arborícola em sete espécies de roedores sigmodontíneos do Cerrado. Os roedores foram capturados no campo e tiveram suas performances avaliadas por meio de medidas de tamanho de passos, frequência de passos e velocidade em cinco suportes horizontais distintos: tábua, e tubos cilíndricos de plástico com diâmetros de 5,0, 3,5, 2,5 e 2,0cm. Nossos resultados revelaram que roedores arborícolas apresentaram maiores velocidades em comparação com roedores mais terrestres. Adicionalmente, as espécies arborícolas mantiveram ou aumentaram a velocidade em suportes com menores diâmetros, enquanto que os roedores terrestres tenderam a reduzir a velocidade. Para as espécies arborícolas, tais velocidades foram obtidas por meio do aumento da frequência de passos e diminuição do tamanho dos passos. Entretanto, espécies primariamente terrestres diminuíram tanto a frequência quanto o tamanho dos passos, ou tenderam a manter a o tamanho de passos e variar a frequência de passos. Nossos resultados revelaram uma forte associação entre capturas acima do solo e o tamanho e frequência de passos. Contudo, tais aspectos da habilidade de locomoção tiveram fraca relação com a massa corporal e não tiveram relação com a filogenia das espécies analisadas. Nossos resultados corroboram a hipótese de que roedores necessitam aumentar velocidade como forma de manter a locomoção arborícola dinamicamente estável. Entretanto, a habilidade de locomoção é provavelmente mais relacionada com fatores ecológicos do que com restrições filogenéticas.

Hantavirus reservoirs: current status with an emphasis on data from Brazil

Since the recognition of hantavirus as the agent responsible for haemorrhagic fever in Eurasia in the 1970s and, 20 years later, the descovery of hantavirus pulmonary syndrome in the Americas, the genus Hantavirus has been continually described throughout the World in a variety of wild animals. The diversity of wild animals infected with hantaviruses has only recently come into focus as a result of expanded wildlife studies. The known reservoirs are more than 80, belonging to 51 species of rodents, 7 bats (order Chiroptera) and 20 shrews and moles (order Soricomorpha). More than 80genetically related viruses have been classified within Hantavirus genus; 25 recognized as human pathogens responsible for a large spectrum of diseases in the Old and New World. In Brazil, where the diversity of mammals and especially rodents is considered one of the largest in the world, 9 hantavirus genotypes have been identified in 12 rodent species belonging to the genus Akodon, Calomys, Holochilus, Oligoryzomys, Oxymycterus, Necromys and Rattus. Considering the increasing number of animals that have been implicated as reservoirs of different hantaviruses, the understanding of this diversity is important for evaluating the risk of distinct hantavirus species as human pathogens.

DNA barcoding of sigmodontine rodents: identifying wildlife reservoirs of zoonoses

Species identification through DNA barcoding is a tool to be added to taxonomic procedures, once it has been validated. Applying barcoding techniques in public health would aid in the identification and correct delimitation of the distribution of rodents from the subfamily Sigmodontinae. These rodents are reservoirs of etiological agents of zoonoses including arenaviruses, hantaviruses, Chagas disease and leishmaniasis. In this study we compared distance-based and probabilistic phylogenetic inference methods to evaluate the performance of cytochrome c oxidase subunit I (COI) in sigmodontine identification. A total of 130 sequences from 21 field-trapped species (13 genera), mainly from southern Brazil, were generated and analyzed, together with 58 GenBank sequences (24 species; 10 genera). Preliminary analysis revealed a 9.5% rate of misidentifications in the field, mainly of juveniles, which were reclassified after examination of external morphological characters and chromosome numbers. Distance and model-based methods of tree reconstruction retrieved similar topologies and monophyly for most species. Kernel density estimation of the distance distribution showed a clear barcoding gap with overlapping of intraspecific and interspecific densities < 1% and 21 species with mean intraspecific distance < 2%. Five species that are reservoirs of hantaviruses could be identified through DNA barcodes. Additionally, we provide information for the description of a putative new species, as well as the first COI sequence of the recently described genus Drymoreomys. The data also indicated an expansion of the distribution of Calomys tener. We emphasize that DNA barcoding should be used in combination with other taxonomic and systematic procedures in an integrative framework and based on properly identified museum collections, to improve identification procedures, especially in epidemiological surveillance and ecological assessments.

FISH with whole chromosome and telomeric probes demonstrates huge karyotypic reorganization with ITS between two species of Oryzomyini (Sigmodontinae, Rodentia): Hylaeamys megacephalus probes on Cerradomys langguthi karyotype

Rodentia comprises 42 % of living mammalian species. The taxonomic identification can be difficult, the number of species currently known probably being underestimated, since many species show only slight morphological variations. Few studies surveyed the biodiversity of species, especially in the Amazon region. Cytogenetic studies show great chromosomal variability in rodents, with diploid numbers ranging from 10 to 102, making it difficult to find chromosomal homologies by comparative G banding. Chromosome painting is useful, but only a few species of rodents have been studied by this technique. In this study, we sorted whole chromosome probes by fluorescence-activated cell sorting from two Hylaeamys megacephalus individuals, an adult female (2n = 54) and a fetus (2n = 50). We made reciprocal chromosome painting between these karyotypes and cross-species hybridization on Cerradomys langguthi (2n = 46). Both species belong to the tribe Oryzomyini (Sigmodontinae), which is restricted to South America and were collected in the Amazon region. Twenty-four chromosome-specific probes from the female and 25 from the fetus were sorted. Reciprocal chromosome painting shows that the karyotype of the fetus does not represent a new cytotype, but an unbalanced karyotype with multiple rearrangements. Cross-species hybridization of H. megacephalus probes on metaphases of C. langguthi shows that 11 chromosomes of H. megacephalus revealed conserved synteny, 10 H. megacephalus probes hybridized to two chromosomal regions and three hybridized to three regions. Associations were observed on chromosomes pairs 1-4 and 11. Fluorescence in situ hybridization with a telomeric probe revealed interstitial regions in three pairs (1, 3, and 4) of C. langguthi chromosomes. We discuss the genomic reorganization of the C. langguthi karyotype.

Morphometric variations of laelapine mite (Acari: Mesostigmata) populations infesting small mammals (Mammalia) in Brazil

The goal of this study was to evaluate the morphometric variation of laelapine populations (Acari, Mesostigmata) associated with neotropical oryzomyine rodents at different geographic localities in Brazil. Three nominal mite species were selected for study, all infesting the pelage of small mammals at different localities in Rio de Janeiro, Espírito Santo, Bahia, and the Federal District, Brazil. To analyse morphometric characteristics, thirty-seven morphological characters distributed across the whole body of each specimen were measured. We use the Analysis of Principal Components, extracting the three first axes and projecting each mite in these axes. Major species level changes in the taxonomy of the host mammals allows an independent examination of morphometric variation of mites infesting a set of distinctly different host species at different geographic localities. Gigantolaelaps vitzthumi and Laelaps differens are associated with oryzomyine rodents of the genus Cerradomys, and consistently showed a tendency to cluster by host phylogeny. Laelaps manguinhosi associated with Nectomys rattus in central Brazil is morphometrically distinct from mites infesting N. squamipes in the coastal restingas of Rio de Janeiro and Espírito Santo. The results obtained here indicate that laelapine mite populations can vary among geographic areas and among phylogenetically related host species. Clearly, the study of these mites at the population level can be an important tool for clarifying the taxonomy of both mites and hosts.

Checklist dos mamíferos do Estado de São Paulo, Brasil

A fauna de mamíferos do estado de São Paulo consta de 231 táxons, sendo este número uma estimativa da real diversidade presente na região, dado a falta de amostragem em grandes extensões do estado, e também de revisões taxonômicas para determinados grupos. Ainda assim, nosso conhecimento aumentou em 20% desde a última estimativa em 1998, principalmente em relação aos quirópteros e roedores. Estes dados são provenientes de inventários faunísticos, e também do estudo de espécimes depositados em coleções científicas oriundos de revisões taxonômicas. Também temos um maior volume de dados a respeito da distribuição dos mamíferos em relação às diferentes paisagens presentes no estado, o que nos permite dividir a mastofauna em três componentes distintos: o mais importante desses é o das espécies generalistas, que ocorrem em todas as principais paisagens do estado; o segundo grupo concentra espécies das formações abertas, e o terceiro grupo inclui as espécies essencialmente florestais. Além disso, o número de estudos que tem se preocupado com o efeito da fragmentação de hábitats sobre as comunidades de mamíferos, bem como a respeito da permeabilidade das espécies em áreas alteradas, também aumentaram. Dados a respeito da ocorrência, abundância e vulnerabilidade das espécies foram essenciais para traçar estratégias em relação à escolha de áreas e à indicação de ações prioritárias para a conservação dos mamíferos no estado, assim como classificar as espécies nas diferentes categorias de ameaças propostas, culminando na Lista das Espécies Ameaçadas do Estado de São Paulo. Entretanto, ainda existem inúmeras lacunas de conhecimento, que vão desde o número limitado de amostras zoológicas, até a falta de informações acerca da ecologia e história natural de várias espécies. É imprescindível que aumentemos as amostras de mamíferos em coleções zoológicas, principalmente em áreas de Floresta Ombrófila Densa, nos fragmentos de Cerrado, bem como em áreas do centro e oeste do Estado, que permanecem ainda pouco estudadas, com o objetivo de produzir um maior número de revisões taxonômicas em diversos grupos de mamíferos, e de estudos com abordagens filogeográficas e de genética de populações, para diagnosticarmos de forma efetiva a riqueza de mamíferos no estado, bem como os mecanismos evolutivos responsáveis por esta diversificação. Aliados a esses estudos serão necessárias abordagens ecológicas para gerarmos conhecimento, que em conjunto, nos permitirá avaliarmos o estado de conservação dos mamíferos de São Paulo e tomarmos decisões sobre as melhores estratégias para manejarmos e preservarmos estas espécies.

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.