Trophy hunting has become a particularly burning issue since the emergence of its possible use as a conservation tool. For trophy hunting-based conservation programmes to be sustainable, there is a need to (1) understand how trophy hunting works economically and socially, and (2) assess any potential threats to the conservation of the species that are being exploited.
In Palazy et al. (2012), we showed that trophy hunters attribute a higher value to rare species. This valuation of rarity could lead to increased exploitation (driven by demand and the economic return to the communities), in turn leading to even further rarity, and so on. This process, called the anthropogenic Allee effect (AAE; Courchamp et al., 2006), represents a potential threat which should be taken into account when setting up trophy hunting management schemes.
While it is true that species' extinction due to trophy hunting has never been reported, as stated in Mysterud's (2012) commentary, there are documented cases of unsustainable trophy hunting. Among the most topical examples is the decline of the lion (Panthera leo) and cheetah (Acinonyx jubatus) populations because of trophy hunting (Whitman et al., 2004; Packer et al., 2009, 2011). It is also the case that we still lack clear evidence that populations of ungulates in particular are pushed towards extinction by trophy hunting; however, there are clear examples of unsustainable exploitation related to male hunting in eland Taurotragus oryx, sable antelope Hippotragus niger and reedbuck Redunca arundinum (Caro et al., 1998, 2009). That some species benefit from trophy hunting, such as the Markhor Capra falconeri pointed out by Festa-Bianchet (2012), is very encouraging; however, individual cases should not mask how uncommon such situations are, nor understate the threat that trophy hunting can represent when exemplary management is not achieved.
Our claim in Palazy et al. (2012) is not that trophy hunting cannot be sustainable, but rather that the irrational value put on rare species can jeopardize the good management of rare species for conservation. Other studies have provided evidence of the valuation of rarity in trophy hunting and the relationship between trophy prices and demand: for example, a recent study assessing the valuation of African species hunted for their trophies showed that rarity was an important factor (Johnson et al., 2010). Upgrading the International Union for Conservation of Nature status (increasingly threatened) of the trophy species has been linked to an increase in trophy prices related to a higher demand in African bovids (Prescott et al., 2011) and other taxonomic groups (Palazy et al., unpubl. data). Lastly, an unexpected positive correlation between protection status and hunting pressure has also been found in trophy-hunted felid species (Palazy et al., 2011); trophy hunting of lions, panthers (Panthera pardus), pumas (Puma concolor) and cheetahs increased despite worrying declines in their populations. Beyond this evidence, we totally agree with Festa-Bianchet (2012) that trophy hunting is not the only wildlife-based economic market that can trigger an AAE. In fact, we have already highlighted this process, for instance in luxury goods, ecotourism and animal collections (Gault, Meinard & Courchamp, 2008; Hall, Milner-Gulland & Courchamp, 2008).
We also agree with Mysterud (2012) that rarity may not be the sole characteristic motivating trophy hunters. Size does matter and always will, especially given the existence of record books for hunting trophies. Rarity cannot and should not be considered as the sole motivator for trophy hunters. However, when rarity per se is valued along with other species characteristics, then there is a risk of racing for the remaining trophy animals and any risk should be given proper, case-by-case, consideration. In Palazy et al. (2012), we showed that trophy hunters would pay high sums of money to hunt rare species, regardless of the trophy size. This is supported by the general absence of price variation according to trophy size for rare species as compared with a positive relationship in common species in the trophy price lists proposed on hunting tourist operator websites. In our analyses, the effect of species' rarity on the trophy price is obvious despite its lower effect as compared with body mass. With an R2 of more than 10%, the effect of rarity cannot be considered to be weak. When removing the Markhor from the model, which as suggested by Festa-Bianchet (2012) could have a strong influence on the pattern we reported, the effect of rarity retains an explanatory power more than 10% (R2 of 11.2 vs. 12.7, Edwards et al., 2008). In the database, six other ‘rare’ species (excluding rhino species) with a trophy size below the average are priced above US$10 000.
Lastly, as noted by Festa-Bianchet (2012), while it is true that increased fees will put the rare trophies out of reach of the vast majority of hunters, it is however unlikely to have a bearing on the AAE. The important question should be how many of the most wealthy hunters are willing to pay to hunt those rare individuals. When some species are reduced to a few hundred individuals, even small hunting pressure applied by a few wealthiest hunters might be sufficient to endanger them. In addition, although we generally agree with Festa-Bianchet's (2012) comments, we do not believe that the AAE we discussed in Palazy et al. (2012) is restricted to legal hunting. On the contrary, if rarity is disproportionately valued, and quotas of legal harvesting are lower than the demand, there is an increased risk of illegal hunting to meet the demand (Clayton et al., 2000; Bulte & Damania, 2005; Hall et al., 2008; Palazy et al., 2011). Illegal hunting generally escapes direct management policies of trophy hunting, thus we urge managers to include our AAE results when setting management plans for rare species.
The AAE is a feedback loop that precipitates the decline in the population sizes of rare species towards extinction. As such, the AAE is difficult to demonstrate in living species, as it relies on the availability of ecological and economical data on an exploited species that is often plummeting towards extinction or has already disappeared. When empirical data are not available, one need to be aware of the possibility of an AAE in an economic market based on wildlife trade and insure that it will be avoided. For this reason, we strongly agree with Festa-Bianchet (2012) that understanding the motivations of trophy hunters is key to circumvent AAEs and implement the most sustainable management. We are currently working on this topic and hope to provide yet another step towards a better understanding of the relationships between trophy hunting and conservation biology.