Differential impacts of forest-based livelihoods on mammalian occupancy in southeastern Nicaragua

Background/Question/Methods

Rapidly changing resource levels drive local users to shift their activities, often resulting in unintended consequences to wildlife and creating challenges for conservation initiatives. Remote communities on the southeastern coast of Nicaragua are shifting from predominantly fisheries-based natural resource usage to forest-based farming, hunting, and gathering. In a study of terrestrial mammals near small villages, we hypothesized that as hunting and farming pressure increased, occupancy would decrease due to increasing human pressures on the forest. We expected large-bodied mammals to experience the greatest decrease in occupancy, followed by meso-carnivores and, ultimately, generalist prey species. We used camera traps to capture images of terrestrial mammals at 80 unique sites in 2010, 2012 and 2014. We placed cameras in lowland rainforest adjacent to nine small villages in the Southern Caribbean Coast Autonomous Region. We analyzed detection/non-detection data using single-season occupancy models with distance, livelihood, and interaction covariates.

Results/Conclusions

Occupancy of low-sensitivity species (agouti, paca, armadillo, coati, and white-tailed deer) was affected by all three livelihood and all three interaction covariates in 2010, but none in 2012 or 2014. The most significant of these covariates was main effect of farming (β_farm = -1.44, 95% CI = -2.95 – -0.91). Moderate-sensitivity species (ocelot, margay, jaguarundi, tayra, and collared peccary) were affected by all three livelihood and two of three interaction covariates in 2010. The most interesting of these covariates was the main effect of hunting (β_hunt = 2.04, 95% CI = .41 – 4.34). For high-sensitivity species (jaguar, puma, tapir, white-lipped peccary, and red brocket deer), no covariate was significantly related to occupancy. While an increase in farming provides food and edge habitat for generalist herbivores, it is likely that farmers increased eradication effort in the immediate vicinity of their crops. The positive effect of hunting in 2010 can be explained by an increase in the common prey source between the moderate-sensitivity species and hunters. From 2012 to 2014, changes in livelihood activities did not drive significant decreases in occupancy in any of the high, moderate, or low sensitivity groups. These results indicate that the impact of community livelihoods can change significantly over time.