Mon, Aug 02, 2021:On Demand
Background/Question/Methods
The application of indigenous and local knowledge (ILK) has recently emerged as a means of increasing understanding of elusive wildlife species. However, few studies have examined methods of incorporating data derived from ILK with conventional scientific data. Moreover, most studies of ILK are based on interviews rather than participatory surveys conducted by the knowledge holders. Here, participatory ILK surveys are incorporated with conventional surveys to improve occupancy estimates of ocelots (Leopardus pardalis) in the northwestern Bolivian Amazon. Conventional surveys consisted of 151 camera trap stations installed in 1 km2 quadrants across three study sites for 48 days each. For the ILK surveys, experienced Tsimane-Mostene and Tacana indigenous guides paired with scientists to conduct three 600-m transect surveys for ocelot tracks in 140 of the quadrants. The observations from both methods were combined into a single-season occupancy model that also included environmental and detection variables. In addition, separate single-season occupancy models were generated from each individual survey type to determine method-specific sources of variation in detection probability.
Results/Conclusions The two methods resulted in spatially complementary, rather than duplicate, detections of ocelots in 56% of surveyed quadrants. This is further illustrated in the combined-method occupancy model, which found a higher average probability of ocelot occupancy across the landscape (Ψ = 0.98, SE = 0.05) than either the camera-only (Ψ = 0.80, SE = 0.09) or ILK-based track-only (Ψ = 0.68, SE = 0.11) models. Because the ILK-based transects surveyed a wider spatial area of each quadrant during a single point in time, they encountered different detections than the camera stations, which monitored a single point over a season. The probability of detection was not significantly different between camera traps and the ILK-based track methods. Furthermore, the ILK-based track surveys cost about 85% less than the conventional surveys due to the expense of camera traps and extra months of labor. Thus, ILK-based track surveys can provide complementary understanding of ocelot occupancy and are well-suited for rapid assessments or to improve camera trap placement and minimize the number of cameras needed. Ultimately, I recommend both methods be implemented with ILK holder participation to maintain adequate understanding of carnivore populations, reduce monitoring costs, and benefit communities.
Results/Conclusions The two methods resulted in spatially complementary, rather than duplicate, detections of ocelots in 56% of surveyed quadrants. This is further illustrated in the combined-method occupancy model, which found a higher average probability of ocelot occupancy across the landscape (Ψ = 0.98, SE = 0.05) than either the camera-only (Ψ = 0.80, SE = 0.09) or ILK-based track-only (Ψ = 0.68, SE = 0.11) models. Because the ILK-based transects surveyed a wider spatial area of each quadrant during a single point in time, they encountered different detections than the camera stations, which monitored a single point over a season. The probability of detection was not significantly different between camera traps and the ILK-based track methods. Furthermore, the ILK-based track surveys cost about 85% less than the conventional surveys due to the expense of camera traps and extra months of labor. Thus, ILK-based track surveys can provide complementary understanding of ocelot occupancy and are well-suited for rapid assessments or to improve camera trap placement and minimize the number of cameras needed. Ultimately, I recommend both methods be implemented with ILK holder participation to maintain adequate understanding of carnivore populations, reduce monitoring costs, and benefit communities.