Jonathan Pledger/Shutterstock

President Trump Was Right. Trophy Hunting Puts Species at Risk of Extinction

For once, the science is on the President's side.

SCIENCE AF STAFF
29 NOV 2017
 

There's been a lot of news recently about trophy hunting. Earlier this month, President Trump halted his administration's decision to allow the import of elephant trophies from Zimbabwe and Zambia until he was able to review "all the conservation facts."

 

According to The New York Times, Trump was not aware of the decision to lift the ban until learning it from the news media. A couple days later, he condemned the practice on Twitter:

Now, a new study from the Queen Mary University in London (QMUL) has shed some scientific light on the issue.

The study suggests when hunters target high quality male animals, they could be placing the species at greater risk of extinction.

In many animal species, the males are the ones with largest and most sought-after secondary sexual traits, like antelope horns, deer antlers, lions' manes, and yes, elephant tusks too. These beautiful appendages are often targeted by hunters for their pleasing aesthetic and high price tag.

But there is a hidden cost.

The largest and most impressive animal ornaments are often indicative of how evolutionarily fit that animal is. So when hunters prey on these animals, oftentimes they remove the best genes from the population.

 

"Because these high-quality males with large secondary sexual traits tend to father a high proportion of the offspring, their 'good genes' can spread rapidly, so populations of strongly sexually selected animals can adapt quickly to new environments," said lead author of the study Dr. Rob Knell.

"Removing these males reverses this effect and could have serious and unintended consequences."

Even at low hunting rates, targeting these animals can deplete their numbers to dangerous levels. In some circumstances – for instance when a population is faced with a changing environment - the researchers predict hunting as low as five percent of these high quality males can lead to extinction.

"This demonstration that trophy hunting can potentially push otherwise resilient populations to extinction when the environment changes is concerning," said Dr. Knell, from QMUL's School of Biological and Chemical Sciences.

Dr. Knell says selectively hunting these males – also known as "selective harvest" – would have little effect if the environment was relatively constant. But thanks to human activity that is not the case. 

"... environmental change is now a dangerous reality across the globe for considerable numbers of species," he said.

 

For a long time it was thought well-managed harvests had little effect on the overall population because hunters tend to target only males. But using a computer simulation model Dr. Knell and his team have predicted a different result.

Trophy hunting is a powerful industry in Sub-Saharan Africa. In fact, the area set aside for hunting in the region surpasses the land protected in national parks. So putting a stop to it altogether will be difficult. However, Dr. Knell and his team have some ideas about how hunting practices can be improved to protect animals from extinction.

To fix the problem, the researchers suggest removing only older males that have already had the chance to reproduce.

"Our results clearly show that age restrictions on harvest which allow males to breed before they are taken is effective at reducing the impact of selective harvest on adapting populations," said Dr. Knell.

"When properly regulated trophy hunting can be a powerful force for conservation which is why we're suggesting a different management approach as opposed to calling for a ban."

The study has important implications for the current debate surrounding elephant trophy hunting. That's because - in part - elephant tusks function as secondary sexual traits. Therefore, poachers who target elephants based on their tusk size could be placing species at greater risk than scientists originally thought.

For once, the science is on President Trump's side. Let's hope he doesn't change his mind.

The study was published in Proceedings of the Royal Society B: Biological Sciences.