Infrastructure development poses a significant and escalating challenge to biodiversity conservation efforts. Dams and fences impede wildlife dispersal and migrations (Section 5.1.1), power distribution lines and high-rise buildings pose a collision hazard to birds and bats (Rushworth et al., 2014; Frick et al., 2017), and city expansions compete with biodiversity for space. Expanding road networks are particularly harmful because roads open new areas for deforestation, urban sprawl, agricultural expansion, and unsustainable hunting (Laurence et al., 2006; Benítez-López et al., 2017). A recent review found that 75% of Sub-Saharan Africa’s development corridors—large-scale infrastructure developments meant to stimulate economic growth—would cut through sparsely-populated and low-quality agricultural, range, and forest lands (Laurance et al., 2015; Sloan et al., 2016). These developments not only threaten the wildlife living within those areas (Benítez-López et al., 2017), but also the carbon-sequestering potential of large swathes of tropical forests (Laurance et al., 2015). Most alarming, the corridors’ planners have shown very little regard for existing biodiversity conservation efforts, given that the proposed transportation network cuts directly through 408 existing protected areas, which includes 69 national parks, biosphere reserves, World Heritage Sites, and Ramsar wetlands (Sloan et al., 2016). In contrast, only five of the 33 planned and active development corridors would cross areas of low conservation priority and with promising agricultural potential (Laurance et al., 2015).
Improving existing infrastructure in disturbed and populated areas makes more economic sense than creating new developments in wilderness areas.
Conservation versus development is not a zero-sum game. Rather, biodiversity conservation improves our own well-being by enabling us to obtain the necessary resources to support our livelihoods and our industries’ profit margins (Chapter 4). One way to maintain these benefits while also promoting economic development (Section 15.1) is to focus on improving existing infrastructure in disturbed and populated areas, rather than creating new developments that bisect marginal lands, protected areas, and wilderness areas. Developing marginal lands and wildernesses seldom makes sense, not only because these areas are sparsely populated, but also because many are low-nutrient environments that would never support sustainable agriculture (Balmford et al., 2001; Laurance et al., 2015).
When new developments are necessary, there are usually opportunities to balance diverging interests. For example, to offset the large land footprint of renewable energy, new wind farms and transmission cables could be directed to already degraded land. In many cases, the compromise might even contribute more to socio-economic developmental goals than the original plans. This was well illustrated in Tanzania, where a proposed road development would have disrupted the famous Mara-Serengeti migration route for large mammals, with potentially dire consequences to the area’s ecotourism industry (Dobson et al., 2010; Holdo et al., 2011). To avoid such an impact, scientists used computer models to identify an alternative route that would not only minimise disturbance, but also achieve greater socio-economic development (Hopcraft et al., 2015). Studies, such as these, have provided important foundations for similar work to mitigate the impact of fences on wildlife (Durant et al., 2015), and by making minor adjustments to shipping lanes to reduce collisions between whales and ocean-faring vessels (Silber et al., 2012).
There are also opportunities to make existing infrastructure more wildlife friendly. Of interest is the maintenance of connectivity despite the presences of potential barriers such as fences and roads. For example, strategically placed fence-gaps and exclusionary fences, as well as tunnels placed under fences can be used to facilitate continued dispersal of selected species in fenced areas (Dupuis-Desormeaux et al., 2018). Similarly, warning signs (Figure 14.5), overpasses (e.g. Ford et al., 2009) and underpasses (e.g. Dell’Amore 2012) along paved roads can keep motorists safe from collisions with large animals. One study from Canada found that strategically placed wildlife crossings could reduce vehicle collisions involving large mammals by 96% (Ford et al., 2009), also reducing the chance of human injuries and damage to vehicles (Huijser et al., 2009). While this field of research is still relatively new, much headway has been made in making wildlife crossings cost-effective (https://arc-solutions.org) and determining their optimal placement (Bastille-Rousseau et al. 2018).