MATERIAL AND METHODS

Study Area

We worked in two landscapes of Colombia, South America, as part of an ongoing biodiversity conservation and monitoring initiative. The first one (MML) is located within the Middle Magdalena River valley, and has temperatures averaging between 23 °C to 29 °C and an average precipitation of 2,900 mm/year. It overlaps the municipalities of Yondó (Antioquia), Puerto Parra and Cimitarra (Santander), and extends over an area of 253,600 has, from which 57% correspond to agriculture land use. This landscape presented a total forest loss of 29, 631 ha between years 200 and 2014 according to data from Hansen et al., (2013). The second landscape (OL), is situated within the Bita River basin, in the municipality of Puerto Carreño (Vichada), in the Orinoquia region, and has average temperatures between 23 °C and 36 °C and an average precipitation range of 2,000 – 3,000 mm/year. It spans an area of 407,400 ha, from which 64% are natural savannas (grasslands), 15% natural forests and 2.3% wetlands; while only 1% are agriculture land uses, mainly pastures for livestock. This landscape lost around 74 ha of forest between 2000-2014 according to data from Hansen et al., (2013).

Sampling

We divided the landscape into a 1x1km grid, and located sampling stations within 11-27% of the cells, trying to cover as much habitat heterogeneity as possible while constrained by access and permits to enter private properties. Thus, the spatial sampling unit was a 1x1km cell, and each sampling station consisted of a camera trap with movement and infrared sensor (Reconix HC 500 Hiperfire) for detecting terrestrial birds and medium-size and large mammals. We installed 68 sampling stations in the MML between January-May of 2017 and 76 stations between January-April in the OL, both periods corresponding to the dry season in each landscape. Additionally, we conducted three independent 800 meter transects within sampled cells to look for signs and prints of ungulates and primates. Total sampling effort was 4,569 and 3,763 nights-camera in the MML and OL respectively. Cameras were active an average of 67 nights in the MML and 49 nights in the OL.

Covariables

One of our hypotheses is that factors that determine occupancy can vary across landscapes. We assessed this by evaluating the effect of multiple covariates on occupancy of studied species in each landscape. We included covariates from two categories, those corresponding to natural factors and those related directly or indirectly to anthropic factors. The first category included the area of total forest, the area of each type of forest according to a Corine Landcover classification (riparian forest and high-ground forest in MML and flooded forest in OL), area of natural grasslands (savanna), area of wetlands, and distance to water bodies. These areas were estimated for each 1 x1 Km cell and in a surrounding 1km buffer to explore different spatial scales of the effect. The second group of covariates included distance to closest human settlement, distance to roads, area of pastures (artificial land cover), and the area of open pastures and secondary vegetation. We also used land cover types to evaluate covariates affecting the probability of detection for each species. All variables were estimated using ArcGIS (ESRI 10.2.1).