What determines the scale of landscape effect on tropical arboreal mammals?

Influence of landscape structure on previous exposure to Leptospira spp. and Brucella abortus in free‐living neotropical primates from southern Brazil

“…The scale of the effect (1400 m) observed for this predictor in terms of exposure to the agent also reveals that landscape fragmentation can affect important ecological processes at a large scale. This perception has been corroborated by other researchers, who point to a tendency for the scale of the edge density effect to be greater in relation to forest cover, matrix permeability, and fragment density in arboreal mammals (Cudney-Valenzuela et al, 2022;Galán-Acedo et al, 2018). In this sense, we suggest that this metric of landscape configuration can operate by regulating large-scale processes, such as dispersion and metapopulation dynamics in larger territorial extensions in arboreal mammals (Cudney-Valenzuela et al, 2022;Ewers & Didham, 2006;Galán-Acedo et al, 2018).…”

“…Hence, it is possible to consider that the increase in edge density affects larger mammals, such as howler monkeys at larger spatial scales, since they can often rely on larger home ranges (Cudney‑Valenzuela et al, 2022; Fahrig et al, 2019; Galán‐Acedo et al, 2018; Tucker et al, 2014). Thus, in addition to the lower host mobility being an important limiting factor in the transmission and exposure to the pathogen in the habitat, the magnitude of the scale of the effect might be associated with the increase in the effects of the density of edges in the home range used by primates throughout the landscape.…”

Tropical forest loss impoverishes arboreal mammal assemblages by increasing tree canopy openness

“…Mammal surveys are detailed elsewhere (Cudney‐Valenzuela et al, 2021 ; Cudney‐Valenzuela, Arroyo‐Rodríguez, Andresen, et al, 2022 ), but a brief overview is given here. As suggested by Fahrig ( 2013 ), sampling effort was not proportional to patch size, but standardized across landscapes with different proportions of forest cover to avoid potential confounding effects related to the so‐called “sample‐area effect.” Within the same vegetation plots, we selected five focal trees with suitable climbing conditions (branches ≥20 cm wide, preferably hardwood species) and whose architecture allowed installing a camera trap facing other main branches.…”

“…As we did not know a priori which was the best scale to assess direct and indirect forest cover effects, we followed the protocol suggested by Jackson and Fahrig ( 2015 ) to identify the scale of effect of forest cover. The analyses for calculating the scale of effect are detailed elsewhere (Cudney‐Valenzuela, Arroyo‐Rodríguez, Andresen, et al, 2022 ), but a brief overview is given here. First, we adopted a site‐landscape approach (sensu Brennan et al, 2002 ), in which response variables were measured in same‐sized sample sites (i.e., five focal trees at the center of each forest patch), and forest cover (in percentage; i.e., area covered by old‐growth forest divided by landscape size × 100) was measured within 11 circular concentric radii (300‐m to 1300‐m radius, at 100 m intervals) from the geographical center of each forest patch (Figure 1 ).…”