The primary sampling methods we use to study amphibian and reptile species in the Peruvian Amazon include line transects, intensive quadrat searches, opportunistic surveys of specific sometimes seasonal habitats, pitfall trap lines, and caiman surveys by boat. In a typical week, 5 to 6 nights are dedicated to line transect, quadrat or opportunistic sampling and 1 to 2 nights to caiman surveys in large rivers or streams. Once established, pitfall traps are actively functioning at active field sites on a daily basis. Line transect sampling is conducted within 1-hectare plots consisting of eleven evenly-spaced 100m long transect lines. Each research site contains 2-4 transect sampling plots. Quadrat sampling plots are conducted within separate 1-hectare plots, each divided into 10x10m quadrats or squares. Each research site contains 1-2 quadrat sampling plots. Opportunistic sampling sessions are conducted within seasonally available locations within a site, such as temporarily flooded forests, swamps, bamboo thickets, mixed agriculture-forest mosaics, and micro-habitats that require rapid biodiversity assessments. Specimen specific variables such as perpendicular distance to transect line, micro-habitat features and specimen height are recorded for each individual encountered. Pitfall trap lines consist of four pitfall traps (70-litre buckets) spaced 10m apart for a total distance of 30m per trap line. Temporary plastic barriers are placed above these traps to funnel terrestrial herpetofauna and occasionally small mammals into these bucket traps. Each research site has 2 to 4 pitfall trap lines. During pitfall-based surveys, specimens are captured and placed separately into appropriate bags for later processing (i.e. careful identification and collection of morphological data) back at camp, after which they are released near to the point of capture. Selected species considered to be too delicate are not taken back to camp, and instead are identified, processed, and released in the field. The morphometric data collected on each captured individual include age class, sex, snout to vent length (SVL), total body length (TBL) and weight. Caiman sampling on navigable rivers is conducted by boat and on streams by foot. River surveys are conducted along transects that are approximately 4 linear kilometres in length. At each site, there are between 2 to 4 of these river transects. Stream surveys are also conducted within transects, however the length varies greatly depending on the characteristics of each stream. The number of stream transects varies greatly between sites (mean 2, range 0-4). Caimans are captured when possible and processed at the point of capture, either within the boat or on the stream bank. Morphological data collected include age class, sex, SVL, TBL and weight. In addition, a Passive Integrated Transponder (PIT) tag is inserted in the tail area of each caiman to assist with mark/recapture studies. Caimans are released immediately following processing at the site of capture. In addition, data on habitat variables in the vicinity of transects, quadrats, pitfall trap lines and opportunistic sampling areas are collected using 0.05-ha Modified Gentry plots. All of the above data is used to assess diversity, relative abundance and population density of species using standard analytical protocols, as well as occupancy modelling to predict species distributions and habitat suitability. Data analysis and visualisation programs that we use include R, Distance, QGIS, SPSS, Mark, and Estimates.