“Scientific adaptive management and monitoring can theoretically remedy the negative ecological effects of trophy hunting, including artificial selection and demographic and social disruption.”

Once a model such as ours has been parameterized for a species it may be readily adapted for conservation decision making, as are classic matrix models (30, 31), but with the advantage of being able to explore both demographic and evolutionary outcomes of alternate strategies. … In the absence of data or models it is probably advisable that regulatory rules mimic natural mortality schedules in males, because this should minimize the risk of undesirable consequences of demographic change, as well as evolutionary change were it sufficient to leave a population-level signature.

We used an individual-based model to explore whether selective compensatory culling of 'low quality' individuals at an early life stage can facilitate sustainability, as suggested by information from managed game populations in eastern and central Europe. … Simulations showed that targeted culling of low-quality yearlings could counter the selective effects of trophy hunting on the distribution of the affected trait (e.g. antler or horn size) in prime-aged individuals.

Therefore, there is a clear need for trophy hunting management to be underpinned by a strong scientific basis for determining sustainability of legal hunting offtakes. … Early models demonstrated the importance of incorporating social behavior and territoriality into population simulations for lions and were used as the basis to simulate population control regimes (including culling and contraception) in southern African protected areas19–21. … That study proposed that trophy hunting is sustainable if only male lions aged a minimum of 6 years old are hunted. This recommendation has been widely adopted by resource managers in range states where lion trophy hunting occurs22.

Trophy hunting is often cited as a tool to conserve large mammal populations but may also have negative impacts if not well managed. … We confirm the results of previous studies that show that lion trophy hunting can be sustainable if only older male lions are hunted, but demonstrate that hunting becomes unsustainable when populations are exposed to additional anthropogenic mortality, as is the case for most free ranging populations. … Finally, errors in aging of hunted lions by professional trophy hunters may undermine the sustainability of the age-based quota setting strategies that are now widely used to manage lion trophy hunting.

Selective hunting avoiding negative selection pressure on populations (e.g., species-specific age limits, preference for animals near or at post-breeding age, no pressure on genetically dominant and healthy animals, clear quotas)

Our theoretical work showed that, within the bounds of a series of empirically well-supported assumptions, compensatory culling of poor-quality individuals at an early life stage had the potential to at least partially compensate for the trait-altering effects of trophy hunting in the short and intermediate term (up to 100 years).

Based on dynamics of the Serengeti lion population, the restriction of trophy harvests to males of six-years or older effectively ensures sustainability of harvest in the absence of reliable population estimates [34], [35]. … Reforms are arguably preferable to trade bans because they would provide scope for the retention of financial and economic incentives for the retention of land for wildlife and for tolerance of lions, while reducing the negative impacts on lion populations.

We strongly encourage those responsible for managing harvested wild populations to take into account possible selective effects of harvest management and to implement monitoring programs to detect exploitation-induced selection before it seriously impacts viability.

One of the tools being applied to ensure the sustainable offtake of past prime male lions with minimal disruption of pride coalitions is an age-based quota system that involves monitoring and evaluating the lion trophies taken each year.

Trophy hunting may not necessarily lead to irreversible trophy size over time but requires systematic monitoring and sound management interventions for sustainability [101].

Trophy hunting impacts large predator populations. Hunting quotas need to be limited, well managed and monitored to reduce negative effects.

Around the world, many conservation and natural resource agencies advocate using adaptive management when deciding how to conserve wildlife and ecosystems in the face of uncertainty. … A foundational principle of adaptive management is ongoing monitoring of systems as regulations change to generate valuable insight into system functioning that can feedback into future policy formation [46].

Although the empirical basis for advice is currently weak, managers aiming to avoid artificial selection should also maintain a ‘natural’ population structure and target a high proportion of individuals that have not reached the age of maturity.

The criteria stipulate that only specific individuals (notably old males) can be hunted where their removal will further demographic and/or genetic conservation of breeding populations.

By providing a reproductive advantage to males with smaller horns and reducing the availability of desirable trophies, however, excessive harvest may have the undesirable long-term consequences of reducing both the harvest and the horn size of rams. These consequences can be avoided by limiting offtake.

We investigated the effectiveness of the rule for adaptive harvesting under different levels of monitoring uncertainty and poaching uncertainty.

Although more experimental than observational studies reported demographic side effects, we argue that this may reflect the quite subtle mechanisms involved, which are unlikely to be detected in observational studies without rigorous monitoring regimes.

The comparison of harvesting strategies showed that the adaptive approach outperformed proportional harvesting by reducing variation in the quota when poaching occurred at an unknown level.

Human actions have the potential to generate artificial selection and evolution in wild populations (Hendry et al., 2017; Stockwell et al., 2003), and one of the most important agents of anthropogenic selection can be harvest (Fugère & Hendry, 2018).

A clear understanding of the importance of evolutionary change due to selective harvesting is of critical importance to those responsible for managing harvested wild populations (Allendorf and Hard 2009) . … Given the substantial economic importance of trophy hunting (Foote and Wenzel 2009) and its potential role in conservation (Leader-Williams et al. 2001) , it is critical to assess what levels of selective harvest can drive evolution in game species.

Drawing on insights from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Sustainable Use Assessment (SUA) (IPBES, 2022) and informed by new CITES guidance on non-detriment findings (NDFs), these new guidelines are in accordance with the IUCN policy statement on sustainable use (IUCN, 2000) and complement existing guidance related to harvesting, including on the use of trophy hunting as a conservation tool (IUCN SSC, 2012) and the use of IUCN Red List data in harvest decisions (IUCN, 2022).

Selective removal of individuals through culling or trophy hunting can affect not only the demographic but also the socio-spatial parameters of the targeted population (Macdonald et al., 2006).

When rigorously managed, trophy hunting areas may be relevant conservation areas for large herbivores, particularly under the current global decline of wildlife abundance across Africa.

Although our analysis does not establish that evolution of smaller horns caused the observed decline in both horn size and harvest of trophy rams, we suggest that intensive trophy hunting may have artificially selected for a decrease in horn growth rate.

We find that body size is weakly inherited and that subsequently demographic change, and not evolutionary change, as previously thought, is the principle driver of trait shifts in hunted bighorn sheep.

Declines in mean breeding values for weight and horn size therefore occurred in response to unrestricted trophy hunting, resulting in the production of smaller-horned, lighter rams, and fewer trophies.

Although more experimental than observational studies reported demographic side effects, we argue that this may reflect the quite subtle mechanisms involved, which are unlikely to be detected in observational studies without rigorous monitoring regimes.

The potential evolutionary effects of selective hunting of mammals are debated due to insufficient evidence and significant socioeconomic implications (Festa-Bianchet, 2017).

Our simulations suggest that the effects of size‐selective harvest on male horn length in hunted populations can be dampened or avoided if harvest pressure is low, migration rate is substantial, and migrants leaving protected areas have a low risk of being shot.

Some studies have called for dramatic changes in harvest management to alleviate the negative effects of selective harvest on ungulates without actually demonstrating any evolutionarily relevant artificial selection (Bischof et al. 2008, Fenberg and Roy 2008, Mysterud and Bischof 2010, Mysterud 2011, Pelletier et al. 2014).

Our goal here is neither to oppose hunting nor to promote it. Rather, we hope to demonstrate how hunting might impact elephant populations and to suggest practices for mitigating any harms to the population and Botswana’s wildlife-based economy.

Adaptive management A decision process that promotes flexible decision making that can be adjusted in the face of uncertainties as outcomes from management actions and other events become better understood. Careful monitoring of these outcomes advances understanding and helps adjust policies or operations as part of an iterative learning process.