Climate change threatens older elephants most, jeopardizing their future

A collaborative team of researchers from the University of Massachusetts Amherst and the Wildlife Conservation Society (WCS), which runs the world’s largest field conservation program, has conducted first-of-its-kind research on how global climate change affects African elephants.

The work, recently published in Sustainability and transformation of PLOS, shows that older elephants will have significantly reduced chances of survival, which will not only significantly reduce the species’ overall ability to withstand climate change, but will also have ripple effects throughout the surrounding landscape. The team also modeled possible mitigation scenarios, which WCS is already implementing.

The Greater Virunga Landscape (GVL) of Africa is a 15,700 square kilometer area of ​​savannahs, mountains and lakes in Uganda, Rwanda and the Democratic Republic of Congo. It is home to Africa’s largest land animals, with seven national parks, three rainforest reserves and three wildlife reserves, three of which are World Heritage sites, covering 88% of the area. It is also home to a population of African elephants whose numbers have fallen so precipitously over the past century that they are now listed as critically endangered on the International Union for Conservation’s Red List.

Elephants play a key role in modifying and maintaining their landscapes by dispersing the seeds of the plants they feed on, felling trees and enriching soil fertility with their dung. They also play an important role in many African cultures.

To date, few studies have focused on environmental dynamics, climate change, elephant demographics, and how habitat changes influence elephants over long periods of time. To get a clearer idea of ​​what the future of elephants might look like and what we can do to best ensure their survival, lead author Simon Nampindo, who carried out this research as part of his Ph.D. in environmental conservation at UMass Amherst and now national director of WCS Uganda, and Timothy Randhir, professor of environmental conservation at UMass Amherst, built a dynamic systems model.

“This model,” explains Nampindo, “can look at all the different environmental and demographic dynamics within a system. For the first time, we are able to get a holistic view of what the future of African elephants. climate change.”

Nampindo and Randhir built their model using data on elephant numbers, historical landscape changes and different climate change scenarios representing warming of 1.6°, 2.8° and 4.3° Celsius over the of the next 80 years. Finally, they mapped the effect that each of the climate scenarios would have on five age groups of elephants: under 10 years, 11-30 years, 31-40 years, 41-50 years and over 50 years, because, as Randhir says, “any impact on one age group has a community effect on the entire population.”

“We found that older elephants will be massively affected by warming in all scenarios,” says Nampindo. “Elephants are matriarchal: their leaders are the eldest cows, and herds depend on their wisdom, long memories and ability to outwit prey. If they disappear due to climate change, that will also cause wreak havoc on younger, surviving herds. while altering genetic profiles and herd structures. There will also be ripple effects across the GVL landscape.

“But,” says Randhir, “this model not only tells us what the threats are, but we can also use it to tell us which policy options will be most effective in helping African elephants survive.”

In the case of a species like the elephant, which migrates widely across national borders, it is particularly important to also understand how different policies might affect future herds so that management agencies can coordinate their responses.

In particular, Nampindo and Randhir believe that a coordinated GVL management strategy at national, regional and local levels is necessary to address poaching threats. Well-funded anti-poaching efforts are essential, but they also highlight the importance of community programs and education in frontline towns and villages where human-elephant interaction is common. The GVL landscape must also be managed appropriately to reduce the impact of habitat fragmentation, fire and invasive species.

“These results are very important for WCS,” says Nampindo. “If we can do a good job protecting elephants, our efforts will trickle down to other species, like lions and mountain gorillas.”

“More broadly,” says Randhir, “the most interesting thing about this dynamic systems modeling is that it can be adapted to all migratory species that cross political borders, from fish to birds to lions. “