The conservation of tropical forest carbon stocks offers the opportunity to curb climate change by reducing greenhouse gas emissions from deforestation and simultaneously conserve biodiversity. However, there has been considerable debate about the extent to which carbon stock conservation will provide benefits to biodiversity in part because whether forests that contain high carbon density in their aboveground biomass also contain high animal diversity is unknown. Here, we empirically examined medium to large bodied ground-dwelling mammal and bird (hereafter "wildlife") diversity and carbon stock levels within the tropics using camera trap and vegetation data from a pantropical network of sites. Specifically, we tested whether tropical forests that stored more carbon contained higher wildlife species richness, taxonomic diversity, and trait diversity. We found that carbon stocks were not a significant predictor for any of these three measures of diversity, which suggests that benefits for wildlife diversity will not be maximized unless wildlife diversity is explicitly taken into account; prioritizing carbon stocks alone will not necessarily meet biodiversity conservation goals. We recommend conservation planning that considers both objectives because there is the potential for more wildlife diversity and carbon stock conservation to be achieved for the same total budget if both objectives are pursued in tandem rather than independently. Tropical forests with low elevation variability and low tree density supported significantly higher wildlife diversity. These tropical forest characteristics may provide more affordable proxies of wildlife diversity for future multi-objective conservation planning when fine scale data on wildlife are lacking.

Objectives of tradable permit programs are often broader than internalizing an externality and improving economic efficiency. Many programs are designed to accommodate community, cultural, and other non-efficiency goals through restrictions on trading. However, restrictions can decrease economic efficiency gains. We use a policy experiment from the Alaska halibut and sablefish tradable permit program, which includes both restricted and unrestricted permits, to develop one of the few empirical measurements of the costs of meeting non-efficiency goals. We estimate that restrictions are reducing resource rent in the halibut and sablefish fisheries by 25% and 9%, respectively.

Recent estimates reaffirm that conservation funds are insufficient to meet biodiversity conservation goals. Organisations focused on biodiversity conservation therefore need to capitalise on investments that societies make in environmental protection that provide ancillary benefits to biodiversity. Here, we undertake the first assessment of the potential ancillary benefits from the ballot box in the United States, where citizens vote on referenda to conserve lands for reasons that may not include biodiversity directly but that indirectly might enhance biodiversity conservation. Our results suggest that referenda occur in counties with significantly greater biodiversity than counties chosen at random. We also demonstrate that large potential gains for conservation are possible if the past and likely future outcomes of these ballot box measures are directly incorporated into national-scale conservation planning efforts. The possible synergies between ballot box measures and other biodiversity conservation efforts offer an under-utilised resource for supporting conservation.

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