Resumo A densidade de populações é um parâmetro chave em conservação e ecologia, mas é uma métrica difícil de se obter para espécies raras e de hábitos crípticos. Nós desenhamos uma matriz de armadilhas fotográficas para capturar o elusivo tatu canastra (Priodontes maximus), estimamos sua densidade usando modelos de captura e recaptura espacialmente explícitos, e comparamos essa estimativa com àquela obtida em um estudo anterior de oito anos de telemetria realizado na mesma área. A densidade obtida através do levantamento por armadilhas fotográficas com duração de seis meses (7.69 indivíduos/100km2) é praticamente idêntica àquela obtida no estudo intensivo de telemetria (7.65 ind./100 km2). Nós recomendamos o uso de matrizes sistematizadas de armadilhas fotográficas, que possuem um menor custo financeiro e em termos de mão de obra, ao longo da região Neotropical para obter conhecimento sobre o status populacional de espécies elusivas e informar medidas de conservação.

Abstract Population density is a key parameter in conservation, but remains a challenging metric to obtain for rare and cryptic species. We designed a camera trap array targeting the elusive giant armadillo (Priodontes maximus), estimated densities using spatially explicit capture-recapture models, and compared these with estimates from a previous eight-year telemetry study in the area. Density from the six-month camera trap survey (7.69 individuals/100km2) is nearly identical to that from the intensive telemetry study (7.65 ind./100 km2). We recommend the use of systematic camera trap arrays, which are much less expensive and time consuming, to obtain insights on the population status of elusive species across the Neotropics and inform conservation.

ABSTRACT It is believed that the two species of Tolypeutes Illiger, 1811are the only armadillos that do not dig their own burrows, and that these species simply re-use burrows dug by other species. Here, we show that Tolypeutes matacus (Desmarest, 1804) and Tolypeutes tricinctus (Linnaeus, 1758) dig their own burrows. We describe the burrows and three other types of shelters used by them, and provide measurements and frequency of use of the different types of shelter. We have studied free-ranging individuals of T. matacus in two locations in Central Brazil and individuals of T. tricinctus in semi-captivity in the Northeast of Brazil. Individuals of T. matacus were found primarily in small burrows (76%), straw nests (13%), shallow depressions covered with leaf-litter (7%) or in straw nests made on shallow depressions (4%). Adult males and females of T. matacus did not differ in frequency of use of different types of shelter. Sub-adults T. matacus used shallow depressions and nests more often (40%) than adults (22%) and nurslings (10%). Nurslings of T. matacus reused the shelters more frequently (66%), than sub-adults (46%) and adults (35%). Adult females reused burrows and other types of shelter more frequently than adult males. Tolypeutes tricinctus rested mainly in burrows and under leaf-litter, but did not dig depressions or build nests. Tolypeutes tricinctus occasionally used burrows dug by Euphractus sexcinctus (Linnaeus, 1758), but T. matacus never used burrows dug by other species. Nursling T. matacus always shared shelter with an adult female therefore, both used shelters with similar frequency. Adult females and nurslings of T. matacus reused shelters in higher frequency. That can be explained by the fact that adult females with offspring tend to remain for consecutive nights in the same burrow when cubs are recently born. Due to their smaller body size, sub-adult T. matacus used shelter strategies that require less energetic effort more frequently than adults and nurslings. The habit of covering the burrow entrance with foliage and the burrow's reduced depth, indicates that Tolypeutes use of burrows is more likely to be related to parental care behavior and thermoregulation strategies than to defense mechanisms. We are confident that the burrows used for resting were indeed dug by Tolypeutes because, besides the direct observation of armadillos digging burrows, the measures of the burrows are very distinctive from those presented as characteristic for the co-occurring burrowing species and are congruent with Tolypeutes size and carapace shape. The newly acquired knowledge that species of Tolypeutes dig burrows can be used to increase the well-being of individuals kept in captivity by adapting enclosures to enable their digging behavior. In addition, this information contributes not only to the study of the ecology and natural history of the species, but can shed new light on the study of the anatomy of specialized diggers. Tolypeutes spp. can comprise the least fossorial of all living armadillo species, but they can no longer be classified as non-diggers.

The spiny rats of the genus Trinomys Thomas, 1921 have a broad distribution in the Atlantic Forests of southeastern Brazil. However, some species are known only from their type locality and adjacent areas. In our study, nine areas in the state of Rio de Janeiro were surveyed and three species of the genus were captured - Trinomys dimidiatus (Günther, 1877), T. setosus (Desmarest, 1817) and T. gratiosus bonafidei (MOOJEN, 1948). We extended the distribution of T. gratiosus bonafidei in 100 km, in a straight line to the northwest, and into an area of Semidecidual Seasonal Forest. We captured T. setosus, which had not been previously recorded in the state, in the municipality of Cambuci, extending its distribution 150 km, in a straight line to the east of its closest record, in Juiz de Fora, state of Minas Gerais. The state of Rio de Janeiro has now six recognized species of Trinomys, however none of them were collected above 1300 m of altitude. We used occurrence points provided by our inventories data and from the literature to model the potential distribution of Trinomys species. We used climatic, topographic and phytogeographic variables to prepare the potential distribution maps. The algorithm used for modeling was provided by the software Maxent, version 3.2.1. Although species boundaries within Trinomys in Rio de Janeiro State are not yet clear, their distributions seem to be parapatric, except for T. iheringi and T. dimidiatus.

Mesmo após a devastação de grande parte das suas matas, o Estado do Rio de Janeiro ainda abriga uma grande riqueza de mamíferos terrestres. Contudo, informações sobre abundância e distribuição da mastofauna do Estado ainda são escassas. Este estudo tem como objetivo inventariar os mamíferos do Parque Estadual do Desengano, localizado na região norte do Estado do Rio de Janeiro, uma das regiões menos amostradas e mais alteradas do Estado. O inventário foi realizado utilizando armadilhas do tipo Sherman e Tomahawk, e armadilhas de queda para os pequenos mamíferos não-voadores, redes de neblina para os morcegos, armadilhas fotográficas, avistamentos e relatos de moradores e funcionários do Parque para os mamíferos de maior porte. Nós registramos 56 espécies de mamíferos, das quais 15 constam na lista da fauna ameaçada de extinção do Estado do Rio de Janeiro e 10 na lista da fauna brasileira ameaçada de extinção, incluindo Brachyteles arachnoides. As espécies mais abundantes foram o morcego Sturnira lilium e o roedor Akodon serrensis. Além disso, Thaptomys nigrita, roedor normalmente pouco capturado no Estado, foi relativamente abundante no Parque Estadual do Desengano. Nossos resultados indicam que o Parque abriga 33,7% das espécies de mamíferos com ocorrência conhecida para o Estado, destacando a importância da área para a conservação da fauna do Rio de Janeiro.

Even after the devastation of large part of its forests, Rio de Janeiro State still harbors a rich terrestrial mammal fauna. However, information on the distribution and abundance of mammal species in the State is still scarce. This study aims to survey the mammals of the Desengano State Park, located on the northern part of Rio de Janeiro, one of the least studied and most altered regions of the State. The inventory was conducted using Sherman, Tomahawk, and pitfall traps for non-volant small mammals, mist nets for bats, camera traps, sightings and reports of residents and officials of the Park for large mammals. We recorded 56 species of mammals, of which 15 are on the list of threatened fauna of Rio de Janeiro State and 10 on the list of Brazilian threatened fauna, including Brachyteles arachnoides. The most abundant species were the bat Sturnira lilium and the rodent Akodon serrensis. Moreover, Thaptomys nigrita, a rodent not commonly captured in the State, was relatively abundant in the Desengano State Park. Results indicate that the park harbors 33.7% of the species of mammals known to occur in the State, highlighting the importance of the area for the conservation of Rio de Janeiro fauna.