I gave a presentation on trophy hunting recently, and in preparation was struck by how few data are available for hunted populations across Africa. Why? Trophy hunting generates income for many African countries and provides ‘economic incentives for conservation over vast areas, including areas which may be unsuitable for alternative wildlife-based land uses such as photographic ecotourism’ , and following the advent of the Zimbabwean CAMPFIRE programme, ‘the rate of habitat loss slowed down and in some specific instances was even reversed’ . Despite all this, the lack of scientific contribution to the debate around trophy hunting in Africa appears glaring. But is it?
As a quick analysis, I carried out a review of the primary literature, restricting my search-terms to Africa, trophy hunting and large herbivores only. Here’s what I found:
There are no long-term individual based datasets – for trophy-hunted herbivore populations – where both demographic parameters and targeted traits have been collated (note individual based, not aerial or ground based survey data). So the lack of these data precludes interpretation through use of say integral projection models [as per 3]. A number of papers (n=4) had analysed long-term trends in horn length and tusk weight from trophy records, although these data do not account for trait distribution within/across populations, and assume inheritance. A few (n=3) studies have analysed population density data of hunted populations, and a few papers developed Leslie matrices or individual based models to simulate sustainable offtake (parameterised from survey data). Two papers documented changes to population age-sex structure, and four studies documented shifts in habitat use and behaviour of targeted populations. A few (n=3) articles noted positive outcomes for biodiversity on areas managed for hunting, and five papers linked an increase in demand for trophies to species rarity. The majority of papers (n=14) broadly interpreted the economic costs and benefits of trophy hunting. I could only find one genetic-based study, but I may have missed a few as it is not my field.
So in summary, there is some very clever use of problematic data by scientists working on trophy hunting, but there are very few robust datasets available, despite the importance of trophy hunting to local economies. This may be through lack of funds, logistical constraints and red-tape. It seems to me that setting up long-term individual based studies now may just be too hard, and genetic approaches may provide an alternative, although these are time-consuming It is sad that relatively so little is done to understand the demographic-genetic effects of trophy hunting on African large herbivore populations.
References cited 1. Lindsey PA, Roulet PA, Romanach SS (2007) Economic and conservation significance of the trophy hunting industry in sub-Saharan Africa. Biological Conservation 134: 455-469. 2. Taylor R (2009) Community based natural resource management in Zimbabwe: the experience of CAMPFIRE. Biodiversity and Conservation 18: 2563-2583. 3. Traill LW, Schindler S, Coulson T (2014) Demography, not inheritance, drives phenotypic change in hunted bighorn sheep. Proceedings of the National Academy of Sciences of the United States of America 111: 13223-13228.