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Habitat loss is widely recognized as the main driver of biodiversity loss around the globe, yet the effects of habitat fragmentation on biodiversity have been extensively debated in recent years. We used a robust dataset of medium and large-sized mammals to test (a) the Habitat Amount Hypothesis, which postulates that species richness can be mainly predicted by the total amount of habitat surrounding the sampling site, and (b) the effects of habitat fragmentation per se, which may be expected to be weak or mainly positive on species richness. We compiled information on the occurrence of mammal species in 166 forest fragments across the Atlantic Forest. For each forest fragment, we extracted information on patch size, percentage of forest cover (a proxy for habitat amount), and edge density and number of fragments (fragmentation metrics). We related these metrics to mammalian richness considering separately for all species, forest-dependent species, disturbance-tolerant species, and different trophic guilds. All richness measures strongly declined with decreasing forest cover, yet were unaffected by patch size, number of patches and edge density. The only exception occurred with herbivore richness, which was affected by number of patches. However, we found fragmentation per se effects only for herbivore richness. Our results show that mammal richness increased with habitat amount at the landscape, whereas habitat fragmentation per se had significant negative impacts on herbivores only. We therefore recommend maintaining highly forested landscapes and restoring severely deforested areas, being essential for ensuring high richness of mammals.

Large ground-dwelling Neotropical gamebirds are highly threatened by habitat loss and hunting, but conservationists rarely attempt to distinguish between these two threats in the management of populations. We used three different types of species records to determine the status (i.e. persistence level) of the Endangered red-billed curassow Crax blumenbachii in 14 forest remnants in north-east Brazil, as either persistent, precarious or extirpated. We related these persistence levels to variables measured in a 2-km buffer radius, including variables associated with habitat quality (proportion of forest cover, length of rivers, patch density, distance from rivers) and hunting pressure (proportion of cacao agroforests and farmlands, length of roads, total area occupied by settlements, distance from roads and from settlements). Curassows were more persistent in forest patches located (1) more distant from settlements, (2) in landscapes with few settlements, (3) in landscapes with a high incidence of roads, (4) in a mosaic with a high proportion of forest, shaded cacao agroforest and farmland, and (5) more distant from other forest patches. Hunting pressure potentially exerts more influence on persistence than habitat quality: (1) hunting pressure submodels had a higher explanatory power than habitat quality submodels, (2) final models comprised four hunting pressure variables but only two habitat quality variables, and (3) hunting pressure variables appeared in all models whereas habitat quality variables appeared in only one final model. If hunting pressure is driving declines in curassows, regions with low human presence and a high proportion of forest cover are recommended for establishing new reserves.

We present evidence of plasticity in habitat use and range extension of the striped hog-nosed skunk (Conepatus semistriatus) in Brazil. We first compiled literature records of C. semistriatus across its known distribution (N = 390), added new records from primary data (N = 10), and compared the main landscape composition (forest, savannah, grassland, agriculture) among these occurrence sites (N = 400). We unveil that landscape composition among occurrence sites varied widely within and among biomes in Brazil (Caatinga, Cerrado and Atlantic Forest), indicating C. semistriatus presence from dense forested habitats to grasslands and anthropogenic areas (especially agricultural landscapes). Almost 30% of the occurrence records of C. semistriatus are outside of the species known distribution, including records in ecotones between Cerrado-Amazonia biomes, extending its occurrence area in 449,118 km2. We conclude that habitat modification is a driver for the occurrence of C. semistriatus in dense forested habitats, facilitating its distribution expansion to previously unexpected areas.

RESUMO Avaliar os efeitos das mudanças no uso da terra sobre a biodiversidade se tornou uma questão-chave para conservação das espécies. Para isso, é necessário analisar a configuração e composição da paisagem em que determinada espécie ocorre. O objetivo foi traçar um perfil dos remanescentes florestais de Mata Atlântica localizados no sul da Bahia que apresentam registros atuais e históricos de Crax blumenbachii. Analisaram-se quatorze áreas utilizando diferentes escalas espaciais (escala de mancha, 500 m, 1 e 2 km) para calcular a quilometragem total e a distância mais próxima de estradas e rios até a borda da mancha, porcentagem de área ocupada por: floresta, floresta com cabrucas, pastagem e agricultura; densidade de fragmentos e a proximidade desses fragmentos até a borda de cada mancha, a área ocupada por casas e a distância dessas até a borda da mancha. Selecionou-se a escala de 2 km por melhor descrever a configuração e composição da paisagem. Há dois perfis de áreas com registros de mutum: (1) áreas com paisagens mais florestadas, com mais rios e estradas, pouca pastagem/agricultura e casas próximas, e (2) áreas distantes de casas, com estradas e fragmentos florestais próximos. Estas são caracteristicas de áreas com registros recentes ou históricos de mutum, e não necessariamente refletem qualidade de habitat para a espécie. ABSTRACT Assessing the effects of land use change on biodiversity has become a key issue for species conservation. Thus, it is necessary to analyze the configuration and composition of the landscape where a species occurs. The objective was to draw a profile of the forest remnants of the Atlantic Forest located in the south of Bahia state that present current and historical records of Crax blumenbachii. We analyzed fourteen areas using different spatial scales (patch scale, 500 m, 1 and 2 km) to calculate the total distance and distance from roads and rivers to the edge of the patch, percentage of area occupied by: forest, forest with cabrucas, cabrucas, pasture and agriculture; density of fragments and the proximity of these fragments to the edge of each patch, the area occupied by houses and their distance to the edge of the patch. We selected the 2 km scale to best describe the configuration and composition of the landscape. There are two profiles of areas with records of red-billed curassows: (1) areas with more forested landscapes, rivers and roads, low pasture/agriculture, and near human settlements, and (2) areas distant from houses, near roads and forest fragments. These features are related to areas with recent or historic records of red-billed curassows, and do not necessarily reflect habitat quality for the species.