Poor management in protected areas is associated with lowered tropical mammal diversity

Abstract

Numerous protected areas (PAs) have been created worldwide to safeguard wildlife and other natural resources from anthropogenic threats such as habitat destruction and bushmeat hunting. However, conservation efforts in many tropical PAs are still inadequate, revealing deficiencies in management effectiveness. It is therefore important to quantify how different protection regimes impact wildlife within PAs. We investigated the differences between forest mammal communities in two ecologically comparable PAs in the Udzungwa Mountains (Tanzania) with contrasting management regimes. One is a well‐protected national park with efficient law enforcement; the other has suffered decades of inadequate protection, mainly resulting in high levels of illegal hunting. Using camera‐trapping data, we assessed the target communities in terms of species richness, functional composition (i.e. proportions of trophic guilds) and species‐specific occurrences, all while accounting for imperfect detection. We found striking differences between the two mammal communities: lower species richness, alteration in the trophic structure and reduced occurrence probabilities for most species in the forest with high disturbance. The difference in occurrence probability between the two PAs tended to be highest for larger‐bodied species. Our results show that strictly enforced legal protection is required to maintain diverse mammal communities in tropical forests under ever‐increasing anthropogenic threats. While PAs are the cornerstone of efforts to conserve tropical biodiversity, the future of biodiversity within them is closely tied to the effectiveness of enforcement.

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

“…There is a need to understand the priority area for conservation and key species on which to concentrate efforts. Documenting the status of two mammal communities in a poorly studied country like Myanmar, we found patterns that were comparable with other studies in tropical forest communities in terms of the number of species [ 13 , 32 , 47 ]. Surprisingly, we found two similar communities in terms of shared species (22), despite the distance between the two study areas, with only a few differences depending on different geographical ranges.…”

“…Using a hierarchical modeling framework with a Bayesian formulation [ 28 , 29 ], we focused on the estimation (while accounting for imperfect detections [ 28 ]) of the following parameters: (1) estimated species richness for the whole community used as a proxy of species diversity and representing the most direct measurement of biodiversity [ 30 ] and (2) estimated species richness and proportion within the community of two important functional traits such as trophic niches and body mass. These two traits were largely used in these models to evaluate the general community functional composition [ 13 , 31 , 32 ]. Finally, we also focused on (3) multi-season occupancy estimates since this parameter is widely used as a proxy for population density that often is difficult, if not impossible, to measure [ 33 ].…”

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

“…That forest antelopes in the UMNP seem stable and relatively widespread as compared to other African parks is confirmed by another recent study (O'Brien et al, ). Significant declines have been previously documented for Philantomba monticola and Cephalophus spadix across some forest reserves in Udzungwa (Nielsen, ), whose protection has been recorded as less effective (Jones et al, ; Oberosler et al, ). Yet, small levels of illegal hunting and human disturbance seem to have no direct effect on duikers' occupancy patterns over time in the target national park.…”

“…This is also consistent with results from a previous study over the same study area (Rovero et al, ), which reported that estimated group abundance of arboreal primate species appeared stable over an 11‐year period (2002–2012). In contrast, most species declined severely in a nearby nature reserve, due to high levels of uncontrolled illegal hunting (Hegerl et al, ; Oberosler et al, ; Rovero et al, ). These authors report a marked difference between this nature reserve and MW in terms of PA management indicators, that is, the annual budget allocated for forest management (USD c. 1,000 vs. 400,000, respectively) and the number of permanent staff units (1 vs. 78, respectively, with the latter number, related to the whole national park, including 60 rangers that are regularly involved in patrols).…”

Responses of carnivore assemblages to decentralized conservation approaches in a South African landscape

“…Proactive management practices have been shown to positively influence carnivore communities (Farr, Green, Holekamp, Roloff, & Zipkin, 2019; Oberosler, Tenan, Zipkin, & Rovero, 2019), yet this is unlikely to be the explanation for observed differences in carnivore occupancy between the protected area and private reserve (Figures 2–4) since anti‐poaching efforts and management capacity are similar. Spatial variation in lion encounter risk also did not influence carnivore occupancy as we might have expected based on evidence of top‐down suppression of sympatric carnivores by lions (Vanak et al., 2013).…”