No abstract

Large continuous rainforests are the main hope for sustaining the population of large-bodied vertebrates that cannot cope with fragmentation or unsustainable hunting. The Brazilian Atlantic forest is considered a biodiversity hotspot and although highly fragmented, it still contains large forest patches that may be important for the conservation of mammals that require large areas. Here, we estimated species richness, density and biomass of medium- and large-sized mammals along the largest remnant of the Atlantic rainforest, Brazil (the Serra do Mar bioregion), an estimated area of 8000 km2. We recorded 44 species based on 4090 km of diurnal line transects and camera traps, animal tracks and interviews in 11 continental regions and two large land-bridge islands. We found high levels of similarity in mammalian composition between pairs of sites in the continental forest sites (0.84-1), but much lower similarity between pairs from the continental forest sites and the two large land-bridge islands (0.29-0.74) indicating potential local extinctions or poor dispersal of continental mammals to these islands. In addition, we found that the density and biomass varied 16- and 70-fold among sites, respectively. Mammalian biomass declined by up to 98% in intensively hunted sites and was 53-fold lower than in other Neotropical non-fragmented forests. Although this large forest remnant is able to maintain a high diversity of medium- and large-bodied mammal species, their low density and biomass may affect the long-term persistence of these populations and the ecosystem services they provide

Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data.

The continued degradation of forest habitats and isolation of fragmented populations means that the conservation of endemic marmosets in the Brazilian Atlantic forest depends on human interventions including legal protection. Population monitoring is required to ensure effective management and appropriate allocation of conservation resources; however, deriving estimates of population metrics such as density within heterogeneous environments is challenging. We aimed to quantify the population density and spatial distribution of buffy-tufted-ear marmosets (Callithrix aurita) in the northern region of Serra-do-Mar State Park. We incorporated habitat suitability as quantified by a niche modeling algorithm (MAXENT) to refine density estimates obtained via distance methods. We used 6 environmental predictors to model the distribution of Callithrix aurita and used the resulting MAXENT niche model to identify environmental conditions that represent suitable habitat for this species. We used 877.7 km of line transect surveys and distance methods to derive estimates of 2.19 groups or 7.55 individuals/km 2 from direct observations (n=40), providing an overall population estimate of 1892 (95% CI=1155-3068) individuals in 250.7 km 2 of Atlantic forest. Our refined density estimate, obtained by combining distance methods and a niche model, yielded a result of 1386 individuals. Suitable habitat was not uniformly distributed across the study area and was most strongly associated with altitude and the type of vegetation cover. We provide a review of previous surveys and find this is the largest known population of Callithrix aurita. Our refinement of density estimates provides a simple and informative addition to the primatologist's toolbox.

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal‐central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation‐related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data.