Assessing conservation monitoring funds: comparison of camera trapping and active search to survey lizards in a xerophytic neotropical forest in Paraguay

Abstract

Background and Research Aims: Sampling squamate reptiles in challenging environments like the Dry Chaco requires efficient methods to overcome logistical and ecological barriers. This study compares the effectiveness of camera trapping (CT) and active search (AS) for surveying lizards in a xerophytic forest in Paraguay, assessing their cost-effectiveness and complementarity. Methods: Species richness was compared across a baseline literature dataset, AS, and CT. Detection efficiency (species per hour) and cost per species detected (CPSD) were calculated. Complementarity between methods was assessed using a Complementary Index (CI). Results: Literature indicated the presence of seven lizard species in the study area. AS detected three species, CT detected four, with two species detected by both methods. CT was more cost-effective (CPSD = $135) but less efficient in terms of effort (0.00062 spp/h) compared to AS (CPSD = $965; 0.0417 spp/h). CI = 0.43, indicating moderate complementarity. Conclusion: Both methods contribute uniquely to documenting lizard diversity, with CT excelling in cost-effectiveness and AS in detection efficiency. Implications for Conservation: Combining CT and AS enhances biodiversity inventories, supporting better conservation planning in remote and arid ecosystems like the Dry Chaco.