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

Abstract:The diet of some sympatric carnivore species in three Atlantic Forest remnants of Southern Brazil was studied in order to assess their food niche. We conducted monthly field trips between February 2003 and January 2004 to collect fecal samples that were subsequently examined together with others collected sporadically between November 1994 and January 2003. Of the 416 samples analysed, 198 had the "author" species identified through microscopic analysis guard hairs, which revealed the presence of 10 carnivores and some information about their diet. Puma yagouaroundi had the largest dietary niche breadth, whereas Leopardus tigrinus and Nasua nasua showed the lowest values. Extensive niche overlap was observed between L. tigrinus and N. nasua, L. tigrinus and L. wiedii, and between L. tigrinus and L. pardalis. Data presented here not only increases the understanding of carnivore feeding ecology, but also contributes towards their conservation in the study region and other fragmented landscapes in Brazil and neighboring countries.

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.

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