Species-rich but defaunated: the case of medium and large-bodied mammals in a sustainable use protected area in the Amazon

Abstract

Neotropical medium and large-bodied mammals are key elements in forest ecosystems, and protected areas are essential for their conservation. In Brazil, sustainable use protected areas (SU-PAs) allow both the conservation of biodiversity and the sustainable use of natural resources, especially in the Amazon region. However, SU-PAs usually suffer both internal and external pressures, and may be subject to variable degrees of defaunation. We sampled mammals using camera traps in two areas with different forest management and human occupation history in the Tapajós National Forest (TNF), in the western Amazon. Overall, we recorded a rich assemblage of medium and large-sized mammals, though both areas differed in species composition. The area with older and more intense human occupation and forest exploitation had more independent records of generalist species, while large species such as Tapirus terrestris and Panthera onca were recorded exclusively in the area with lower human occupation and no forest management. A comparison of our results with similar studies in other Amazonian sites suggests a reduction in the population size of large-bodied mammals, such as Tapirus terrestris and Tayassu pecari, likely in response to increased human activities. Local differences in human occupation within and between protected areas are common in the Amazon, demanding area-specific actions from public authorities to minimize impacts on wildlife caused by human activities. Specifically in TNF, we recommend long-term monitoring of the responses of mammals to human activities, to better subsidize conservation and management actions.

Composition of terrestrial mammal assemblages and their habitat use in unflooded and flooded blackwater forests in the Central Amazon

“…When the data were extrapolated to the same effort/coverage, the overall richness of assemblages was similar in both forest types since, in our study area, both environments are supplied by the same regional species pool, although the terra firme forest has a more stratified forest structure ( Wittmann, Schöngart & Junk, 2010 ; Zapata-Ríos et al, 2021 ). Nevertheless, the total number of species recorded in the Cuieiras River basin were unexpectedly similar to those described in other camera-trap-based studies carried out in the richer productivity habitats of várzea and terra firme forests in the Amazon ( Haugaasen & Peres, 2005a ; Tobler et al, 2008 ; Alvarenga et al, 2018 ; Costa, Peres & Abrahams, 2018 ; Rosa et al, 2021 ). This further indicated that the sampling effort was sufficient.…”

“…Photographs or videos of the same species at the same point taken >60 min apart were defined as independent detection events ( Meek et al, 2014 ). The relative biomass was calculated by multiplying the camera-trapping rate by the mean body mass and mean group size for gregarious species ( Rosa et al, 2021 ). Mean body mass data were obtained from the EltonTraits1.0 database ( Wilman et al, 2014 ).…”

Hotspots and hotmoments of wildlife roadkills along a main highway in a high biodiversity area in Brazilian Amazonia

“…We surveyed wildlife roadkills along 100 km of the BR-163 highway in the state of Pará, in the eastern Brazilian Amazon. In most of the studied section, the road separates the protected area of the Tapajós National Forest, with a high diversity of vertebrates (Henriques et al 2003;Sampaio et al 2010;Rosa et al 2021), from an area with intense changes in the landscape due to agricultural expansion. We aimed to identify points of concentration of wildlife roadkills (hotspots) and to understand the relationship between collisions and seasonality in precipitation and temperature to identify possible temporal aggregations (hotmoments) in roadkills.…”