Pelvimetric characteristics in agoutis (Dasyprocta prymnolopha) bred under human care / Características pelvimétricas em cutias (Dasyprocta prymnolopha) criadas sob cuidados humanos

The aim of the study was to establish the pattern of the agouti pelvis by obtaining external and radiographic internal pelvimetric values. Forty-three agouti (Dasyprocta prymnolopha), females and males bred in under human care were used. The parameters measured were the external biiliac diameter; the external biischiatic diameter; right and left external ilioischiatic diameters and radiographic internal measurements (true conjugated, the diagonal conjugated; the vertical, the sacral, sagittal, coxal tuberosity, upper biiliac, lower biiliac, and biischiatic diameter. The inlet pelvic area and the outlet pelvic area were calculated, as well the height/width ratios of the entrance area of the pelvis and the pelvic outlet area were calculated. The mean values for each body measurement of females and males were: weight 1.91kg and 2.04kg, external biiliac diameter 6.32cm and 6.30cm, external biischiatic diameter 4.34cm and 4.28cm, right external ilioischiatic diameter 9.01cm and 9.33cm, left external ilioischiatic diameter 9.13cm and 9.30cm, true conjugated 3.90cm and 3.68cm, diagonal conjugated 7.13cm and 6.91cm, vertical diameter 2.59cm and 2.45cm, sacral diameter 2.63cm and 2.44cm, sagittal diameter 3.30cm and 3.09cm, coxal tuberosity diameter 2.52cm and 2.43cm, upper biiliac diameter 6.28cm and 6.24cm, lower biiliac diameter 2.98cm and 2.58cm, biischiatic diameter 2.60cm and 2.70cm, height/width ratio - vertical/ lower biiliac diameter 0.88cm and 0.95cm, sagital/coxal tuberosity diameter 1.32cm and 1.28cm, inlet pelvic area 82.38cm and 77.83cm and outlet pelvic area 24.76cm and 20.07cm. Agouti are dolichopelvic animals, demonstrating the existence of a discrete sexual dimorphism in adults and low intensity correlations between the external and internal measures studied.

O objetivo deste estudo foi estabelecer o padrão da pelve de cutia, masculina e feminina, por meio da obtenção dos valores médios da pelvimetria externa e interna radiográfica. Foram utilizadas 43 cutias (Dasyprocta prymnolopha), fêmeas e machos criadas sob cuidados humanos. Os parâmetros medidos foram o diâmetro biilíaco externo; o diâmetro biisquiático externo; diâmetros ilioisquiáticos externos direito e esquerdo e medidas internas radiográficas (diâmetros conjugado verdadeiro, diagonal conjugado, vertical, sacral, sagital, tuberosidade coxal, biilíaco superior, biilíaco inferior e diâmetro biisquiático). A área pélvica de entrada e a área pélvica de saída foram calculadas , assim como foram calculadas as razões altura/largura da área de entrada da pelve e da área de saída da pelve. Os valores médios para as medidas das fêmeas e dos machos foram, respectivamente: peso 1,91kg e 2,04kg, diâmetro biilíaco externo 6,32cm e 6,30 cm, diâmetro ilioisquiático externo 4,34cm e 4,28cm, diâmetro ilioisquiático externo direito 9,01cm e 9,33cm, diâmetro ilioisquiático externo esquerdo 9,13cm e 9,30cm, diâmetro conjugado verdadeiro 3,90cm e 3,68cm, diâmetro conjugado diagonal 7,13cm e 6,91cm, diâmetro vertical 2,59cm e 2,45cm, diâmetro sacral 2,63cm e 2,44cm, diâmetro sagital 3,30cm e 3,09cm, tuberosidade coxal diâmetro 2,52cm e 2,43cm, diâmetro biilíaco superior 6,28cm e 6,24cm, diâmetro biilíaco inferior 2,98cm e 2,58cm, diâmetro biisquiático 2,60cm e 2,70cm, relação altura/largura - vertical/diâmetro biilíaco inferior 0,88cm e 0,95cm, diâmetro sagital/coxal tuberosidade 1,32cm e 1,28cm, área pélvica de entrada 82,38cm e 77,83 cm e área pélvica de saída 24,76cm e 20,07cm. As cutias são animais dolicopélvicos, demonstrando a existência de um discreto dimorfismo sexual em adultos e correlações de baixa intensidade entre as medidas externas e internas estudadas.

AMAZONIA CAMTRAP: A data set of mammal, bird, and reptile species recorded with camera traps in the Amazon forest.

The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer-reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non-invasive method of surveying vertebrates, applicable to different scales of time and space. In this study, we organized and standardized camera trap records from different Amazon regions to compile the most extensive data set of inventories of mammal, bird, and reptile species ever assembled for the area. The complete data set comprises 154,123 records of 317 species (185 birds, 119 mammals, and 13 reptiles) gathered from surveys from the Amazonian portion of eight countries (Brazil, Bolivia, Colombia, Ecuador, French Guiana, Peru, Suriname, and Venezuela). The most frequently recorded species per taxa were: mammals: Cuniculus paca (11,907 records); birds: Pauxi tuberosa (3713 records); and reptiles: Tupinambis teguixin (716 records). The information detailed in this data paper opens up opportunities for new ecological studies at different spatial and temporal scales, allowing for a more accurate evaluation of the effects of habitat loss, fragmentation, climate change, and other human-mediated defaunation processes in one of the most important and threatened tropical environments in the world. The data set is not copyright restricted; please cite this data paper when using its data in publications and we also request that researchers and educators inform us of how they are using these data.

What has become of the refugia hypothesis to explain biological diversity in Amazonia?

The spatial distribution of biodiversity and related processes is the core of Biogeography. Amazonia is the world's most diverse rainforest and the primary source of diversity to several Neotropical regions. The origins of such diversity continue to be an unresolved question in evolutionary biology. Among many competing hypotheses to explain the evolution of the Amazonian biodiversity, one stands out as the most influential: the refugia hypothesis by Jürgen Haffer. Here, we provide a chronological overview on how the refugia hypothesis evolved over the decades and how the criticism from different fields affected its acceptance. We conclude that the refugia hypothesis alone cannot explain the diversification of the complex Amazonian diversity, and perhaps it was not the most important diversification mechanism. However, the debate provoked by refugia has produced a great amount of knowledge on Amazonian climatic, geological, and evolutionary processes, as well as on species distributions, movements, and history.

Spatial patterns of medium and large size mammal assemblages in várzea and terra firme forests, Central Amazonia, Brazil.

Várzea forests account for 17% of the Amazon basin and endure an annual inundation that can reach 14 m deep during 6-8 months. This flood pulse in combination with topography directly influences the várzea vegetation cover. Assemblages of several taxa differ significantly between unflooded terra firme and flooded várzea forests, but little is known about the distribution of medium and large sized terrestrial mammals in várzea habitats. Therefore, our goal was to understand how those habitats influence mammalian species distribution during the dry season. Specifically, we: (1) compared the species composition between a terra firme (Amanã Sustainable Development Reserve) and a várzea forest (Mamirauá Sustainable Development Reserve); and (2) tested the influence of the várzea habitat classes on the number of records, occurrence and species composition of mammalian assemblages. The sampling design in each reserve consisted of 50 baited camera trap stations, with an overall sampling effort of 5015 camera trap days. We used Non-Metric Multidimension Scaling (NMDS) to compare species composition between terra firme and várzea forests, and used Generalized Linear Models (GLM) to assess how habitat types and a habitat diversity index affect mammal distributions. We recorded 21 medium and large sized mammalian species, including 20 species in terra firme and only six in várzea (3443 records). Flood pulse and isolation in várzea forest drove the dissimilarity between these two forest types. In várzea forest, medium size mammals, in general, avoided habitats associated with long flooding periods, while jaguars (Panthera onca) appeared to prefer aquatic/terrestrial transition zones. Habitats that remain dry for longer periods showed more mammalian occurrence, suggesting that dispersion via soil is important even for semi-arboreal species. This is the first study to evaluate differential use of várzea habitats by terrestrial mammalian assemblages.

New-record of the bush dog speothos venaticus in a human-altered landscape in west Minas Gerais, Brazil / Novo registro do cachorro-vinagre speothos venaticus em uma paisagem antropizada no oeste de Minas Gerias, Brasil

The bush dog (Speothos venaticus) is a Neotropical canid with a wide geographic distribution. Although globally listed as Near Threatened, this species was listed as Vulnerable in a recent assessment by the Brazilian government. Few records of this mammal have been reported in the Brazilian Cerrado, and it is considered extinct in several localities as a result of human landscape fragmentation. The record presented here is the first evidence of bush dog presence in the West of Minas Gerais, Brazil, which augments the species distribution with expected occurrence for this region. The study site was a transitional area between the Cerrado and Atlantic Forest biomes, in the Triângulo Mineiro region, which is a highly fragmented landscape, dominated by cattle ranches with exotic pasture species and scattered natural patches. We recorded a single bush dog individual in our survey (4,036 camera trap/night), but our sampling success was expected compared with that of other previous mammal surveys using the camera trapping method, in part, because of the species' elusive behavior and low natural densities. This record enhances knowledge of the S. venaticus distribution. Potentially, we confirm the presence of the bug dog in a region that was regarded being environmentally suitable for this species occurrence, but where it has never been reported. Moreover, our result elucidates the potential of the natural remnants to harbor threatened species in highly human-influenced and non-protected landscapes, which is the dominant scenario found in West Minas Gerais, Brasil.

O cachorro-vinagre (Speothos venaticus) é um canídeo Neotropical com uma ampla distribuição geográfica. Embora seja listada globalmente como Quase Ameaçada, esta espécie foi classificada como Vulnerável em recente avaliação do governo brasileiro. Poucos registros para este mamífero foram reportados no Cerrado brasileiro, sendo considerado extinto em várias localidades como resultado da fragmentação da paisagem provocada pelo homem. O registro apresentado aqui é a primeira evidência de ocorrência do cachorro-vinagre no oeste de Minas Gerais, Brasil, o que confirma a distribuição da espécie com ocorrência esperada para esta região. O local de estudo é uma área transicional entre os biomas Cerrado e Mata Atlântica, na região do Triângulo Mineiro, sendo uma paisagem altamente fragmentada dominada por fazendas de criação de gado com pastagem exótica e fragmentos naturais dispersos. Nós registramos somente um único cachorro-vinagre na nossa amostragem (4.036 armadilhas fotográficas/noite), mas o nosso sucesso de amostragem foi esperado comparado com os resultados de outros levantamentos de mamíferos utilizando o método de armadilhamento fotográfico, em parte, devido ao comportamento alusivo e a baixa densidade natural da espécie. Este registro aumenta o conhecimento da distribuição de S. venaticus. Potencialmente, nós confirmamos a presença do cachorro-vinagre em uma região que foi considerada com adequabilidade ambiental para a ocorrência da espécie, mas onde ela não havia sido reportada até momento. Além disso, nosso resultado também reforça o potencial dos remanescentes naturais em abrigar espécies ameaçadas da fauna em paisagens altamente afetadas pelo homem e não protegidas, a qual representa o cenário dominante encontrado no oeste de Minas Gerais, Brasil.

Ocelot (Leopardus pardalis) Density in Central Amazonia.

Ocelots (Leopardus pardalis) are presumed to be the most abundant of the wild cats throughout their distribution range and to play an important role in the dynamics of sympatric small-felid populations. However, ocelot ecological information is limited, particularly for the Amazon. We conducted three camera-trap surveys during three consecutive dry seasons to estimate ocelot density in Amanã Reserve, Central Amazonia, Brazil. We implemented a spatial capture-recapture (SCR) model that shared detection parameters among surveys. A total effort of 7020 camera-trap days resulted in 93 independent ocelot records. The estimate of ocelot density in Amanã Reserve (24.84 ± SE 6.27 ocelots per 100 km2) was lower than at other sites in the Amazon and also lower than that expected from a correlation of density with latitude and rainfall. We also discuss the importance of using common parameters for survey scenarios with low recapture rates. This is the first density estimate for ocelots in the Brazilian Amazon, which is an important stronghold for the species.

Influence of pitfall designs and use of baits on the capture of small mammals in Southern Minas Gerais State, Brazil / Influência da disposição dos pitfalls e uso de isca na captura de pequenos mamíferos no Sul do estado de Minas Gerais, Brasil

Each kind of trap tends to be selective on species sampled, in a way that each one only reveals part of the abundance and species richness of the community sampled. In this way, in order to know the factors that affect the success of sampling methods is crucial for a better planning of experiments and data analysis. The aim of this study was to evaluate the factors that affect the success of pitfall traps in capturing small mammals, such as trap size, designs and use of bait. The study was carried out in two reserves inside the campus of the Universidade Federal de Lavras (UFLA), in South Minas Gerais State, Brazil. In total, 65 specimens belonging to 8 species were caught. Different types of trap design (Y-shaped and I-shaped) have not influenced the capture success of pitfalls. The same result was obtained for the different size of buckets, in exception for Oligoryzomys flavescens, in which larger buckets were more efficient. The use of baits was considered not necessary.

Cada tipo de armadilha exerce uma seleção quanto às espécies capturadas, de forma que cada uma revela uma fração da riqueza e abundância da comunidade amostrada. Conhecer os fatores que afetam no sucesso dos métodos de captura é de fundamental importância para o planejamento de experimentos e análise de dados. O objetivo deste estudo é avaliar fatores que podem afetar o sucesso de captura dos pitfalls (armadilhas de interceptação e queda), tais como forma da estação de captura, tamanho do balde e presença de isca. As coletas foram realizadas em duas Reservas Florestais localizados no campus da Universidade Federal de Lavras, UFLA, na cidade de Lavras, Estado de Minas Gerais. Ao todo foram capturados 65 indivíduos de oito espécies. A forma das estações (Y ou linha) não influenciou no sucesso de captura dos pitfalls. Os diferentes tamanhos de balde não apresentaram sucessos de captura diferentes significativamente, exceto para a espécie Oligoryzomys flavescens, em que os baldes maiores foram mais eficientes. O uso de isca se mostrou dispensável.