Road development in Asia: Assessing the range-wide risks to tigers

Abstract

Roads are proliferating worldwide at an unprecedented rate, with potentially severe impacts on wildlife. We calculated the extent and potential impacts of road networks across the 1,160,000-km2, 13-country range of the globally endangered tiger (Panthera tigris)—a conservation umbrella species. We found that roads were pervasive, totaling 134,000 km across tiger conservation landscapes (TCLs), even in tiger priority sites and protected areas. Approximately 43% of the area where tiger breeding occurs and 57% of the area in TCLs fell within the road-effect zone. Consequently, current road networks may be decreasing tiger and prey abundances by more than 20%. Nearly 24,000 km of new roads will be built in TCLs by 2050, stimulated through major investment projects such as China’s Belt and Road Initiative. Given that roads will be a pervasive challenge to tiger recovery in the future, we urge decision-makers to make sustainable road development a top priority.

Evidence shortfalls in the recommendations and guidance underpinning ecological mitigation for infrastructure developments

“…The U.K. Government's commitment to rapid housing expansion (Prime Minister's Office, 2020), alongside promises to avert further wildlife declines, illustrates the urgent need for effective EMC to reconcile these goals. If measures fail to mitigate impacts of development on protected species, the impacts of ambitious construction programmes could greatly exacerbate population declines (Carter et al., 2020; Clarke et al., 2013; Torres et al., 2016). However, there was insufficient evidence for their ability of nearly half of EMC measures to compensate for impacts of developments.…”

Impending anthropogenic threats and protected area prioritization for the largest Neotropical apex predator in its Amazonian stronghold

“…The ubiquitous presence of road networks causes negative effects on mammal populations up to 5-km [75], strongly affecting apex predators across the tropics [e.g. 76]. In other Neotropical biomes, such as Atlantic Forest and the Cerrado, roadkills are an important contributor to jaguar mortality, further removing individuals from already depleted populations [22].…”

“…Although tigers are habitat generalists, most populations avoiding heavily disturbed areas and currently only survive in forest ecosystems, and core breeding populations are restricted to protected areas across much of their original range [77]. Accordingly, like in other wide-ranging large carnivores, a comprehensive network of effective protected areas throughout the Amazon is critical for the persistent of jaguar populations [e.g., 6, 76].…”

Five Steps to Inject Transformative Change into the Post-2020 Global Biodiversity Framework

“…This work could yield project-specific action plans that would factor in costs of environmental, social, and climate impacts over the lifetime of proposed developments. Countries for potential focus include Democratic Republic of Congo, New Guinea, Indonesia, Ecuador, Malaysia, Mexico, Peru (Laurance et al 2014 , Johnson et al 2020 ), and multiple nations engaged with China's Belt and Road Initiative (Hughes 2019 , Carter et al 2020 ). Then the secretariat could sponsor pilot projects with those countries that are ready to mitigate (or reduce) infrastructure projects, linking this work to countries’ extant NBSAPs.…”