The civil war also has implications for the animal world. According to a study on constant poaching, Elephants in Mozambique are at risk of never developing prey again.

A robust set of tusks is usually an advantage for elephants, allowing them to dig for water, strip the bark for food, and fight with other elephants. But during episodes of intense ivory poaching, those large incisors become a liability, the study reports.

Now, researchers have identified how years of civil war and poaching in Mozambique have led to a higher proportion of elephants that will never develop tusks.

During the conflict from 1977 to 1992, fighters on both sides slaughtered elephants to obtain ivory to finance the war effort.

 According to the authors of the study, in the region that is now Gorongosa National Park, about 90% of the elephants were killed.

The survivors probably shared one key characteristic: half of the females had no prey by nature. They simply never developed tusks while before the war, less than one fifth of the females had no tusks.

Like eye color in humans, genes are responsible for whether elephants inherit their parents' tusks. Although unreliability was once rare in African savanna elephants, it has become more common - like a rare eye color spreading.

After the war, these surviving females without fangs passed on their genes with expected, as well as surprising, results. About half of their daughters had no fangs. More disconcerting, two-thirds of their offspring were female.

The years of upheaval "changed the evolutionary trajectory of that population," said evolutionary biologist Shane Campbell-Staton of Princeton University who had his findings published in the journal Science.