When parks work: Effect of anthropogenic disturbance on occupancy of tropical forest mammals

Abstract

Protected areas (PAs) in the tropics are vulnerable to human encroachment, and, despite formal protection, they do not fully mitigate anthropogenic threats to habitats and biodiversity. However, attempts to quantify the effectiveness of PAs and to understand the status and changes of wildlife populations in relation to protection efficiency remain limited. Here, we used camera‐trapping data collected over 8 consecutive years (2009–2016) to investigate the yearly occurrences of medium‐to‐large mammals within the Udzungwa Mountains National Park (Tanzania), an area of outstanding importance for biological endemism and conservation. Specifically, we evaluated the effects of habitat and proxies of human disturbance, namely illegal hunting with snares and firewood collection (a practice that was banned in 2011 in the park), on species' occurrence probabilities. Our results showed variability in species' responses to disturbance: The only species that showed a negative effect of the number of snares found on occurrence probability was the Harvey's duiker, a relatively widespread forest antelope. Similarly, we found a moderate positive effect of the firewood collection ban on only the suni, another common antelope, and a negative effect on a large opportunistic rodent, the giant‐pouched rat. Importantly, we found evidence of temporal stability in occurrence probability for all species over the 8‐year study period. Our findings suggest that well‐managed PAs can sustain mammal populations in tropical forests. However, variability among species in their responses to anthropogenic disturbance necessitates consideration in the design of conservation action plans for multiple taxa.

High abundance and large proportion of medium and large duikers in an intact and unhunted afrotropical protected area: Insights into monitoring methods

“…The large duiker population in NNNP is in line with the low illegal human activities in the national park. As seen in other protected areas (Oberosler et al, 2020), NNNP might be very important for the recruitment of duikers into the adjoining logging concessions and so no-take areas can act as a source habitat for duiker recruitment (Clark et al, 2009;Mockrin et al, 2011). Therefore, it is important to set aside untouched areas, such as national parks and no-offtake zones in logging concession to ensure protein supply of local and indigenous populations and for large predators (Henschel et al, 2011).…”

Why we went to the woods?: effects of human disturbance on species presence in a disturbed Myanmar forest ecosystem

“…We modeled occurrence probabilities as a function of the four environmental and human-related variables described before (PRES, EVER, ELEV, VILL). Following Oberosler et al (2020b), we built the model using an autologistic formulation where occupancy in year k is dependent on occupancy in the previous year, k − 1 (Zipkin, Grant & Fagan, 2012). This autologistic model is more efficiently implemented in a Bayesian framework.…”

“…A first step would be to identify the mechanisms of illegal timber trade and how the trade network is structured in order to support the enforcement agencies patrolling the area and empower local communities to protect the forest. Then, conservation actions should also include areas outside protected areas, creating buffer zones to control and regulate human pressure (Cavada et al, 2019;Gaffi et al, 2020;Oberosler et al, 2020b). To discourage hunting activities, the authors in collaboration with locals and NGOs, are working to promote community guardian groups involving members of the local communities trained to patrol and identify illegal activities across our study areas, especially for snares that we were not able to identify with camera traps.…”

Camera Trapping to Assess Status and Composition of Mammal Communities in a Biodiversity Hotspot in Myanmar

“…We then separately ran the multi-season model for each species, for all species with at least 10 detections in both areas. Each single species list was created so that all years contained the same number of camera traps location (rows) and sampling occasion (columns), with the sampling session defined as a five day interval (reasonable average for medium-large mammals [ 46 ]) and the year with less sampling occasions determining how many observations to be extracted from the other two years. We arranged single-species data as 3D arrays, Y i,j,t , where i represents site, j is the sampling occasion, and t is the year.…”