The economic geography of ex situ conservation

We thank Bowkett (2014) and Fa et al. (2014) for their measured reflections on our new comparative study showing that mammals and birds kept in zoos are actually less threatened than even close relatives not held in zoos (Martin et al., 2014). We quickly re-emphasize that the focus of our study is on ex situ conservation attention between close relatives, rather than the broader taxonomic bias mentioned by Fa et al. This unique approach gives our results much of their novelty and robustness. We agree with the main theme of the commentaries, that ex situ conservation is both necessary and necessarily complex. We also offer some further comments. Both Bowkett and Fa et al. highlight that zoos and zoo networks are increasingly important players in global conservation efforts, especially as the predicted biodiversity crisis worsens (c.f. Conde et al., 2011, 2013, Pritchard et al., 2011), and that there are many ways to measure this contribution. These are important facts. It is also true that ex situ programmes can only aspire to support a small fraction of global biodiversity (Rahbek, 1993). That said, the increasingly clear pattern indicating that threatened species and species endemic to high-risk ecosystems are underrepresented within this protected small fraction (Conde et al., 2011, 2013; Fa, Funk & O’Connell, 2011; Martin et al., 2014) should have a strong bearing on the future conservation potential of zoos. As Bowkett (2014) mentions, there are practical reasons why the assemblage of species kept in zoos today takes the form it does (see also Frynta et al. 2013). There is room for more interesting work here – for example testing for the historical influence of colonialism on modern ex situ species assemblages. However, the predicted 21st century biodiversity crisis is likely to require a response of corresponding scale and urgency, and this may involve a shift in the principal roles zoos play (Bowkett, 2009) towards increased ex situ breeding of threatened species. To be clear, while in situ conservation is generally considered preferable to ex situ conservation (Balmford, Leader-Williams & Green, 1996; Snyder et al., 1996), predictions of extreme population declines and extinction rates (e.g. Thomas et al., 2004; Butchart et al., 2010) may put us in a situation where an ever greater number of species either persist in ex situ breeding programmes, or not at all. It also seems reasonable to extrapolate that species considered threatened today are also those most likely to face the greatest immediate risk of extirpation in the future. Bowkett (2014) reminds us that threat status can swiftly change, and that many species not currently considered threatened could rapidly become urgent conservation priorities. This is true; we note that species endemic to high-risk ecosystems – that is those perhaps among the most likely to be prone to fast changes in conservation status – are also under-represented in zoos compared with their wider-ranging close relatives (Martin et al., 2014). If we have as a goal ‘zero extinctions’ (AZE, 2014) under dire predictions for biodiversity threat, prudence would dictate establishing ex situ safety nets for more species that are currently threatened or are likely to become threatened, and sooner, rather than later. Of course, simply arguing this will not make it so, and as Bowkett (2014) points out, there are major obstacles restricting the establishment of new captive breeding programmes. Many species are simply not suited to ex situ conservation, or at least not suited for breeding programmes outside their natural range (Snyder et al., 1996; Bowkett, 2014). Constraints of a financial, ethical, spatial and logistical nature are all important, as are the ‘chimeric’ roles of zoos and the draw towards ‘charismatics’ (Fa et al., 2014). Also of critical importance, as Bowkett (2014) discusses, are the wildlife export, veterinary and other sociopolitical regulations that severely restrict the movement of animals between countries, which can make the establishment of new captive populations very difficult. Even after setting all these aside, we must still deal with maintaining biologically sustainable population sizes and eventual re-introduction once a species is actually in an ex situ conservation programme (Snyder et al., 1996). So, the challenges involved in protecting more threatened species with an ex situ breeding programme are daunting, and the failures of previous conservation planning efforts outlined in Bowkett (2014) underline the great difficulties bs_bs_banner