Use of non-invasive methods to examine species distribution relative to a highway in the Calakmul Region, Mexico.

摘要

In 2007, the Mexican government started to widen Highway 186 that traverses the Calakmul region from two to four lanes. This study uses wildlife occurrence data obtained from systematic sampling and citizen science to examine 1) focal species and functional guild distribution in the road-effect zone of Highway 186; 2) wildlife crossing hotspots using citizen science data; and 3) the use of quantitative and qualitative methods to describe road effects on wildlife. Wildlife was detected using four non-invasive methods: 1) tracks collected on 10 secondary roads perpendicular to the highway, 2) remotely triggered cameras placed along each road at 50m, 750m and 2000m from the highway, 3) community maps placed in four villages along the highway on which residents and non residents indicated where, when and what species they encountered, and 4) interviews with local residents. Differences in species relative activity along sampled roads were compared using Kruskal-Wallis and Mann-Whitney U tests for camera and track data. Wildlife sightings reported in community mapping and interviews were digitized into a GIS and crossing hotspots were identified. Participant comments also were examined qualitatively to explore community perceptions of wildlife. Finally, species accumulation curves, latency to first detection and relative efficiency were compared for each detection method, and a data transformation model of the triangle design was used to corroborate qualitative and quantitative methods to describe overall effects of Highway 186 on wildlife. Cameras and tracking indicated species were more active farther from the highway, but activity differed between species. Crossing hotspots along the highway identified by community mapping and interview data changed between years; overall, four mortality hotspots were identified. Cameras and tracks were more effective at detecting species than community mapping and interviews, but the latter two methods detected some species earlier due to the qualitative nature of the data. Although the quality and information provided by data from each collection method varied, together they provide a more comprehensive view of road effects on wildlife in the region.