War is synonymous with the destruction of human life and livelihood. But ecologists are just now beginning to understand how war also destroys animal lives.

In a letter published in Nature Wednesday, conservation biologists Joshua Daskin of Yale University and Rob Pringle of Princeton University found that 71 percent of protected wildlife habitats throughout Africa overlapped with areas where a sustained, armed conflict or battle resulted in the death of at least one person between 1946 and 2010. Further, the animal populations in those areas included in their study almost always declined after the conflict. Daskin and Pringle focused on 36 species of herbivore mammals across Africa—like elephants, antelopes, buffalo, and giraffes—since population data for large and conspicuous animals, compared to, say, small birds, tends to be more available and robust.

Geographic distribution and frequency of armed conflict in African protected areas from 1946 to 2010. Image: Nature

While it’s discouraging that war results in animal deaths, Daskin told me over the phone that local extinction in battle areas was rare—far rarer than he expected.

“We’d seen the level of devastation that can occur for wildlife populations [after conflict],” Daskin said. “There’s a fairly positive message here in that we saw as few [local] extinctions as we did.”

Daskin said that wildlife populations have an amazing ability to recover after a human conflict, even if they sustain significant losses due to poaching, hunting, habitat loss, or perhaps being caught in crossfire.

“We hope [the study] will inspire additional investment in post-war restoration,” Daskin said, “in wildlife and their habitats, but also in the socioeconomic conditions that are necessary for supporting wildlife conservation.”

Daskin and Pringle told me that they’ve witnessed wildlife restoration after a war firsthand. They worked together at Gorongosa National Park in Mozambique, which lost 95 percent of its biodiversity after a Civil War lasting almost two decades. With local agricultural assistance, conservation education for children, and collaborative ecological restoration on both sides of the conflict, the area has seen a massive resurgence in animal biodiversity, and even some alleviation in human poverty.

The study uses data from conflicts arising from struggles for independence, civil war, and genocide that broke out in the aftermath of violent European colonization, which destroyed countless human lives and livelihoods. One example is the Rwandan genocide of the 1990s, one of the most lethal genocides in human history, which occurred during the Rwandan civil war. Pringle also emphasized that not all animals are equally resilient to human conflict.

“Species differ in their capacity to recover depending on various factors, including the rate at which they reproduce and their vulnerability to human exploitation,” Pringle said.

In other words, you may expect that more deadly conflicts for humans were equally deadly for the animals in the area, but according to the study, this isn’t true. More frequent human battles were more deadly for animals; in other words, the more human battles that arise in one region, the more corresponding deaths among large herbivores such as elephants. This is largely because different animals have different experiences during times of war.

“The example that immediately comes to mind is the black rhinoceros, my favorite animal on the planet, which are inordinately vulnerable,” Pringle said.

Animals like the black rhinoceros have valuable ivory horns, which are often used to finance military activity. Other animals, such as elephants, can be hunted as food more often during times of war due to food insecurity. However, Pringle said that they don’t have enough data to know exactly which consequences of war affected which animals in their dataset the most.

“If we can support people to collect data, then I think we’d be able to learn a lot more about the details of the causal mechanisms,” Pringle said. “We send physicians into conflict zones, we send peacekeepers. I don’t think it’s unrealistic to imagine to send conservation biologists into conflict zones.”

Daskin told me that valuing animal's lives won't stop a human war from occurring, even if we know war hurts animals too. But in the wake of a war, animals have a remarkable ability to unite people.