Populations of large, wild herbivores aren’t doing that great. Some 60 percent of large herbivore species are threatened with extinction thanks to overhunting, poaching, and the depletion suitable habitat. Now, researchers have zeroed in on another human-driven source of trouble for these animals: armed conflict. In Africa, wildlife populations living in regions frequently embroiled in war cope poorly, and suffer substantial population declines.
In recent years, the bulk of armed conflicts have taken place in Africa and Asia—continents that also host the most large mammal species on the edge of extinction. This alignment of war and wildlife certainly seems like it could have major impacts large herbivore populations, but the effects haven’t been well studied. That’s why conservation ecologists Joshua Daskin and Robert Pringle, from Yale and Princeton Universities, respectively, decided to look at at African protected areas and compare known, long-term population trajectories of big herbivores with the relative degree and frequency of armed conflict.
A continent-wide examination of Africa’s protected spaces was a natural choice for the research team. As lead study author Daskin told Earther, the scientists had previously conducted research in Mozambique’s Gorongosa National Park, which lost more than 90 percent of its large mammal species during the nation’s 1977-1992 civil war—and has since rebounded to within 80 percent of its former glory.
“We wondered if the impacts of war on wildlife in Gorongosa were emblematic of its effects elsewhere,” Daskin said
The research team first dug into databases that revealed armed conflict events in and around more than 3,500 protected areas in fifty-one African countries. By standardizing nearly seventy years of conflict occurrence data (from 1946 to 2010), the researchers found an average number of “conflict-years” for each protected area. Continent-wide, seven out of ten protected areas overlapped with a conflict zone during these decades.
To determine how herbivore populations were affected in these conflict zones, the researchers scoured the scientific literature for fine-scale data on the population densities of various species. In the end, the researchers had comparisons between conflict scenarios and population trends for over 250 populations of thirty-six species living in 126 protected areas. The species in question ranged from elephants to antelope to buffalo.
The team also tested the impact of other factors on herbivore populations, like the intensity of the violence, the proximity to urban areas, and the body mass of the species in question.
The results, published today in the journal Nature, show just how vulnerable Africa’s most beloved and charismatic wildlife are to repeated human conflict.
Conflict frequency was the most effective and important predictor of wildlife population trends among all factors. The more often there was armed conflict, the heavier the toll was on local wildlife, with the highest-frequency conflict zones almost invariably causing populations to plummet. Interestingly, conflict intensity didn’t seem to have much influence; rather, the presence of any armed conflict was sufficient to adversely impact animal populations.
To Daskin, this is important information for any future conservation work to take place in conflict zones.
“Our study is the first to provide an estimate of the effects of war on wildlife over long time periods and large (continent-wide) spatial scales,” Daskin said. “This is useful when prioritizing funding for conservation, because it can improve the assumptions that researchers and conservation managers make when planning where to invest in conservation efforts.”
The exact reasons why war appears to negatively affects these herbivores remain a bit murky. Research published in 2016 suggests that much of the ecological impact of war comes from indirect effects, rather than the physical, violent act of war itself. Rhinos and gazelles likely aren’t casualties of weapons and military activity, but victims of the chaos that war leaves behind. The poverty caused when livelihoods are upended, and the breakdown of law enforcement and environmental regulation, all make incidents of poaching and habitat disruption more likely.
Whatever is behind war’s disastrous impact on African wildlife, the good news is that in most cases, it seems as though populations can rebound from the brink. Very few populations were wiped out permanently in this study. Post-conflict, there may be great opportunities for restoration initiatives, said Daskin.
For how to effectively manage wildlife populations when peace comes to a conflict zone, Daskin suggests we look to Gorongosa and its remarkable recovery as an example. A huge part of its success may come from how the park was managed in synchrony with development aid for humans.
“The few remaining wildlife were allowed to reproduce under the watch of park rangers who conduct anti-poaching patrols, but also in conjunction with critical human development programs,” Daskin said. “Providing socio-economic assistance helps alleviate the need for people to hunt wildlife.”
By enacting rapid interventions during ceasefires, the researchers contend that some of the indirect effects of conflict on wildlife may be eased, hopefully ensuring that these iconic, ecologically and economically vital species regain their lost numbers.
Jake Buehler is a Seattle area science writer with an adoration for the Tree of Life’s weird, wild, and unsung—follow him on Twitter or at his blog.