“…For example, shelters for reptiles are positioned to replace disappearing stone walls and hedges (Grillet et al, 2010), bat boxes to compensate for felled cavity trees or restored buildings (Flaquer, Torre & Ruiz-Jarillo, 2006), and nest-boxes to provide additional breeding places for birds and mammals (Goldingay & Stevens, 2009). Yet despite their extensive use in conservation and offsetting programmes, robust evaluations of the benefit of artificial devices in terms of the population viability of the target species are rare (Wesołowski, 2011, but see Bourgeois, Dromzée, & Vidal, 2015). The success of artificial devices is generally evaluated using single indicators, for example, colonization by the target species, (Aleman & Laurens, 2013; Avilés & Sanchez, 2000; Chapman & Blockley, 2009) or, in the best cases, their impact on some selected demographic parameters, such as breeding success or survival (see e.g.…”