Multi-evidence survey of medium and large-sized mammals in a Amazonian wetland from Los Achales Reserve, southern Ecuador

We assessed non-volant medium- and large-sized mammals in a Mauritia flexuosa-dominated wetland within the Los Achales Reserve (southern Ecuadorian Amazon) between January and July 2023. We applied a multi-evidence approach that combined direct observations, tracks and signs, camera trapping, and 37 semi-structured interviews with Shuar residents, yielding 242 field records and 77 hunting reports. Field surveys recorded nine species, while interviews added four additional taxa, for a total of 13 species documented in the study area. The most frequently detected species was Dicotyles tajacu (n = 72). Diversity was moderate (Shannon H′ = 1.812; Simpson 1 − D = 0.800), with assemblage structure dominated by a few disturbance-tolerant taxa. Our results highlight the complementarity of local ecological knowledge and conventional field methods in improving species detection, particularly for elusive taxa. The observed assemblage is consistent with patterns of habitat loss and hunting pressure reported in human-modified Amazonian landscapes. Agricultural expansion, urban encroachment, and sustained hunting likely represent the main drivers of mammal population declines in Los Achales. These findings underscore the need for targeted research and conservation actions, including participatory monitoring approaches, to support the persistence of mammal communities in this underrepresented Amazonian wetland system.