Conservation successes at micro-, meso- and macroscales Navjot S. Sodhi 1 , Rhett Butler 2 , William F. Laurance 3 and Luke Gibson 1 1 Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Republic of Singapore 2 Mongabay.com, PO Box 0291, Menlo Park, CA 94026, USA 3 Centre for Tropical Environmental and Sustainability Science (TESS) and School of Marine and Tropical Biology, James Cook University, Cairns, QLD 4870, Australia Although large-scale biodiversity declines are ongoing, certain conservation actions have made a positive dif- ference. Rates of extinction and endangerment of verte- brate species, for instance, have probably been reduced via conservation interventions. Such conservation actions operate at different spatial scales. Habitat pres- ervation and endangered species recovery are examples of conservation successes at microscales. Mesoscale conservation includes regional cooperation among neighboring countries that has arrested population declines of endangered species, such as mountain gor- illas. At macroscales, public pressure on multinational corporations has sometimes resulted in their abandon- ing environmentally damaging practices or suppliers with poor environmental records. Overall, conservation projects such as these need more long-term funding and greater political and popular support, and must also include provisions to evaluate and document their out- comes. As we discuss here, a focus on conservation successes achieved at different scales can help to pro- mote these aims and guide future conservation victories. The scales of conservation intervention Human actions have been directly or indirectly responsible for biodiversity endangerment on a large scale [1,2]. A recent review suggests that conservation actions have largely failed to arrest the ongoing global collapse in biodiversity [3]; as a consequence, widespread pessimism prevails in the conservation community. What successes have been won are rarely highlighted or fail to attract wide attention [4,5]. Furthermore, conservation projects rarely have clear provi- sions to evaluate their outcomes [6,7]. However, many conservation efforts have been beneficial for biodiversity. For instance, rates of extinction and endangerment of ver- tebrates have probably been reduced because of conserva- tion interventions [8]. There is a clear need to synthesize such information to guide future projects and provide much- needed hope for the conservation community. An important factor that might be crucial to guiding future conservation actions is the scale at which such actions should occur. Here, we highlight successful conser- vation initiatives at micro-, meso- and macroscales, which we define to include both the geographic extent and type of conservation action (Figure 1). Microscale conservation encompasses direct efforts to protect species or habitats, including the creation of protected areas (PAs) and the control of illegal hunting. A regional focus defines meso- scale conservation, which includes transboundary agree- ments and the regulation of international wildlife trade. Macroscale conservation is targeted at global phenomena, and includes changing consumer demands and passing legislation to limit the impact of unsustainable business practices. Conservation actions at these scales might differ or overlap; in fact, some conservation efforts must be advanced simultaneously at multiple scales. We focus here on conservation successes that we feel are inadequately highlighted and merit further attention. Our definition of ‘success’ is admittedly loose and based on any evidence of positive conservation outcomes, such as popula- tion increases of endangered species following targeted interventions. We are aware that some conservation efforts, such as ‘paper parks’ that suffer severe encroachment [9– 12], have failed dismally. Furthermore, some conservation successes are exaggerated [13] and many of those we high- light are imperiled by future threats. As such, it is crucial not to interpret this article as portraying all conservation mea- sures as success stories; we paint here only part of the picture, and arguably a smaller part compared with the grim portrayals in myriad scientific and news articles sug- gesting widespread conservation failures. Yet, to highlight successes that do exist and thereby provide a more balanced view, we provide a broad-brush assessment of conservation achievements spanning more than three decades. Microscale conservation Habitat and species preservation epitomize microscale conservation projects (Figure 1). PAs are key local conser- vation initiatives that are considered essential for preserv- ing remnant habitats and endangered species [14], and several studies from wide geographic locations show that protection confers tangible benefits to biodiversity [15] (but note the limited effectiveness of some PAs, especially in the tropics [9–12]). Thanks to PAs, some megafauna species are flourishing in the Indian subcontinent [16]. Following the establishment of Bardia National Park in Nepal, for example, the density of wild ungulates increased fourfold in just 22 years [17]. This spike in prey base triggered increases in both endangered tiger (Panthera tigris) and Review Corresponding author: Gibson, L. (lggibson@nus.edu.sg). 0169-5347/$ – see front matter ß 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.tree.2011.07.002 Trends in Ecology and Evolution, November 2011, Vol. 26, No. 11 585