From March 1987 to February 1988, Sotalia fluviatilis population size was estimated and behavioral patterns were observed in the Cananéia estuary region, in Southeast Brazil. Field observations were carried out from shore (40, with a mean observation period of 7.76 ± 2.05 hours a day, completing a total of 310.5 hours) and during line transect surveys by boat (55, 10 of them with a mean observation period of 4.44 ± 0.15 hours each and 45 with a mean observation time of 20 minutes, in the totality 64.3 hours). Dolphins occur in this region all year round, most commonly in small groups, with a greater number observed in January 1988, with no seasonal occurrence pattern. Pairs accounted for ca. 30% and calves were seen year round, always accompanied by one or more adults. Juveniles were slightly more common from July to February. More dolphins were seen from 9:00 a.m. to 10:00 a.m. (60.8%) until midday. From fourteen behavioral patterns identified, travelling (46.8%) and feeding (33.9%) were the most frequently observed. Group size and composition differed in each behavioral pattern. Diurnal migration was observed, related with hour and not to tide conditions. Dolphins were seen throughout the estuary. For the whole survey area, population density () was 3.38 ± 1.76 individuals/km², dolphin abundance was found to be 704.8± 367.7 along 10 line transect from April 1987 from, where 82 km were surveyed. In Trapandé Bay, the largest part of the studied area, equaled 12.4 ± 10.3 individuals/km² in the morning and 16.4 ± 13.8 individuals/km² in the afternoon.
De março de 1987 a fevereiro de 1988, foi estudada uma população de Sotalia fluviatilis da região estuarina lagunar de Cananéia, no litoral sudeste do Brasil. Padrões comportamentais foram observados e o tamanho populacional foi estimado. Foram realizadas 40 observações em pontos fixos (média de 7,76 ± 2,05 horas de observação cada, num total de 310,5) e através de 55 transectos lineares de barco (10 com 4,43 ± 0,15 horas de duração média cada e 45 com 20 minutos de duração média cada, totalizando 64,3 horas). Os golfinhos foram vistos nessa região ao longo de todo o ano, com um aumento no número de espécimens em janeiro de 1988, não mostrando um padrão sazonal. Usualmente, estiveram presentes em grupos pequenos, sendo os pares os mais freqüentes (ca. 30%). Filhotes também ocorreram ao longo de todo o ano, sempre acompanhados de um ou mais adultos. Jovens foram mais freqüentes entre julho e fevereiro. A maior quantidade de golfinhos foi vista entre 9 e 10 horas, completando 60,8% das observações até as 12 horas. Foram identificados 14 padrões comportamentais, sendo os padrões de deslocamento (46,8%) e de pesca (33,9%) os mais freqüentes. O tamanho do grupo e sua composição diferiram de acordo com cada padrão comportamental. Migrações diurnas foram observadas, com uma preferência horária e não relacionada às condições de mar...

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.

Karyotypic comparisons among five Akodon species showed that they shared a substantial proportion of their chromosome complements, indicated by distinct homologies between chromosomes, arms, or arm regions despite that this genus is karyotypically rearranged. A comparison with a related outgroup (Bolomys lasiurus) allowed for the recognition of ancestral and derived karyotypic traits as well as for inferring the direction of several chromosome rearrangements. This study indicated that species with lower diploid chromosome number are derived from species with higher diploid number, mainly by 11 fusions and 1 pericentric inversion while the direction of 5 other rearrangements could not be determined (fusions or fissions). UPGMA analyses of karyologic data indicated a topology like (Bolomys lasiurus (Akodon sp. (A. lindberghi (A. montensis (A. aff. cursor, A. cursor))))).

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.

Among the Oryzomyini (Sigmodontinae), Oecomys is the most speciose, with 17 species. This genus presents high karyotypic diversity (2n = 54 to 2n = 86) and many taxonomic issues at the species level because of the presence of cryptic species and the overlap of morphological characters. For these reasons the real number of species of Oecomys may be underestimated. With the aim of verifying if the taxon Oecomys catherinae is composed of more than one species, we made comparative studies on two populations from two regions of Brazil, one from the Amazon and another from the Atlantic Forest using both classical cytogenetics (G- and C-banding) and comparative genomic mapping with whole chromosome probes of Hylaeamys megacephalus (HME), molecular data (cytochrome b mitochondrial DNA) and morphology. Our results confirm that Oecomys catherinae occurs in the southeast Amazon, and reveal a new karyotype for the species (2n = 62, FNa = 62). The comparative genomic analysis with HME probes identified chromosomal homeologies between both populations and rearrangements that are responsible for the different karyotypes. We compared our results in Sigmodontinae genera with other studies that also used HME probes. These chromosomal differences together with the absence of consistent differentiation between the two populations on morphological and molecular analyses suggest that these populations may represent cryptic species.