Biodiversity loss in deforestation frontiers: linking occupancy modelling and physiological stress indicators to understand local extinctions

ASUNCIÓN SEMPER-PASCUAL; JULIETA DECARRE; MATTHIAS BAUMANN; JUAN MANUEL BUSSO; MICAELA CAMINO; BIBIANA GÓMEZ-VALENCIA; TOBIAS KUEMMERLE

BIOLOGICAL CONSERVATION

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2019 p. 281 - 288

0006-3207

Tropical deforestation is a main driver of the global biodiversity crisis. Impact assessments typically focus on species? presence, which means deforestation effects can only be detected when local extinctions have already occurred ? and thus when it is too late. Here, we pioneer the combined use of two approaches that can detect deforestation impacts earlier: (1) occupancy modelling, which can proxy abundance changes at the population level, and (2) stress hormonal indicators, which detect impacts within populations. We tested this approach for the collared peccary (Pecari tajacu) in the Argentine Chaco, a global deforestation hotspot. We used camera-trap data to model peccary occupancy in relation to woodland cover and loss, and measured fecal glucocorticoid metabolites in peccary feces to assess individuals? stress level in deforestation areas. We found that peccary occupancy was highest in areas with high woodland cover, but low in areas where deforestation occurred recently. Peccaries were typically absent from areas where deforestation was widespread in the recent past. Where peccaries were present, food limitation seemed to be the main factor causing stress, not ongoing deforestation. This, and the observation that peccaries disappear relatively quickly following deforestation in the landscape, suggests that peccaries do not adapt well to the new conditions in deforestation frontiers. In terms of conservation, our results highlight the importance of large, contiguous woodland blocks to maintain peccaries, and likely many other species in the Chaco landscape. More broadly, we show how combining stress hormonal indicators and occupancy modeling can provide deep insights into processes underlying local extinctions