Unfortunately, many big species now face extinction due to their value in the illegal wildlife trade, vulnerability to habitat degradation and because they often come into conflict with humans.
The African tropics host many of these remaining megafauna or large animals like gorillas, elephants and hippos, but they are now losing ground.
African forest elephants, for instance, have a population just 10% of their potential size, occupying 25% of their potential range.
Knowing how much influence these large animals have on the functioning of our world – and how vulnerable they are to extinction – it’s more important than ever to monitor and restore the health of their remaining populations and the safe havens that support them.
We wanted to know how elephants are faring in Lopé National Park, a 5000 km² protected area in the heart of Gabon. Researchers at the site have observed some of the highest densities of forest elephants ever recorded.
Lopé National Park has a rich diversity of wildlife, including forest elephants, chimpanzees, gorillas and mandrills. Many of these wildlife species rely on wild forest fruits for food.
In our recently published paper we analysed 32 years of valuable data about tree behaviour and found that – between 1986 and 2018 – there was a massive collapse in fruiting events.
This has resulted in a fruit famine and, based on a body condition score applied to archived photographs, an 11% decline in the physical condition of the elephants at our study area since 2008.
The implications of this finding are that even where forest elephants and other megafauna are relatively well protected from external threats such as hunting, global human pressures – such as the climate crisis – could affect their survival.
A collapse in fruiting also means that the forests themselves may be undergoing significant change, with some trees species possibly reproducing slower than required to support a healthy population.