Local and landscape influences on the habitat occupancy of the endangered maned sloth Bradypus torquatus within fragmented landscapes

Abstract

The transformation of natural landscapes in extensive anthropogenic areas has significantly affected ecological processes, and studies that evaluate such changes are essential for the definition of conservation strategies. In this study, we sought to identify the variables influencing the occupancy of Atlantic forest fragments by the endemic and endangered maned sloth. We selected 33 sampling stations, distributed at least 500 m apart throughout the municipality of Santa Maria de Jetibá-ES, Brazil. We sampled each station five times to verify the presence or absence of the species and to collect local variables. Using GIS tools, we defined a buffer of 200 m around each fragment and calculated the landscape metrics. After analysis of collinearity, we selected six variables-three local variables, two at patch level and one at landscape level-to assess their effect on the occupancy and detection probabilities. We selected models using AICc and calculated the weight of evidence and ratio of the models as well as the cumulative weight of each predictor variable. We detected the sloth in 48% of the stations. Its occupation was positively correlated to two variables on the local scale: Important Feeding Trees and Canopy height. Our results show that the maned sloth respond to fine local scale variables, but not to landscape structure. This is probably associated with the relatively high proportion of forest cover in the study area, but it also indicates the maned sloth flexibility to occupy fragmented landscape. Based on our results, we reinforce the unquestionable importance of local variables for species occupancy within fragmented landscapes, such as those related with the forest structure, and it is particularly important for strictly arboreal species.

Multi-Scale Landscape Influences on Genetic Diversity and Adaptive Traits in a Neotropical Savanna Tree

“…Changes in landscape structure, such as habitat amount, edge effect and heterogeneity, can affect essential ecological processes such as dispersal (Corlett, 2017;Bovo et al, 2018), seed predation (Mendes et al, 2016), and pollination (Hadley and Betts, 2011;Duarte et al, 2018), and consequently compromise population persistence (Santos et al, 2016;Regolin et al, 2017). Landscape changes may also affect population connectivity and genetic diversity in different taxa (e.g., Dixo et al, 2009;Carvalho et al, 2015;Jackson and Fahrig, 2016;Moraes et al, 2018;González-Fernández et al, 2019).…”

The demography of a resource specialist in the tropics: Cecropia trees and the fitness of three-toed sloths

“…However, the proportion of regenerating forest in the core area of individuals was not associated with any vital rate. Research is increasingly finding that three-toed sloths are capable of using and persisting in modified habitats [38,39,67], especially shade-grown agricultural systems due to the canopy cover, connectivity, and food resources that they possess [67,68]. Nevertheless, late-stage regenerating forests are critical in specific stages of the life history of sloths; Garcés-Restrepo et al [39] found that during the natal dispersal, juvenile three-toed sloths were strongly tied to riparian forests, which was critical for their dispersal and overall population viability.…”

Estrutura e Composição de Fragmentos de Mata Atlântica Habitados por Callicebus coimbrai no Nordeste do Brasil: Subsídios para Estratégias de Manejo da Paisagem

“…Consequently, the forest composition and structure may suffer essential changes, with a decrease of large trees and an overall simplification of forest structure due to habitat isolation and subsequently edge effects (Rocha-Santos et al, 2016). This shifting in the habitat may have severe consequences on arboreal animal species, which depend almost exclusively on arboreal trees (Santos et al, 2016(Santos et al, , 2019. Considering forest-dwelling species, such as Neotropical primates, the combination of those factors may be crucial to their diversity (Gouveia et al, 2014) and maintenance (Terborgh, 1983;Kinzey, 1997).…”