Two or more dead elephants in one place means one thing: poaching by professional killers. Another tip-off is the lack of a face, as poachers hack off the tusks to be sold for ivory. That ivory is then made into valuable trinkets in Asia or even parts of violin bows in Europe and North America. The proceeds often fund terrorism and other criminal enterprises. And such poaching is causing populations of African elephants to decline by at least 2 percent per year since 2010, according to a new paper published in Proceedings of the National Academy of Sciences. At least 100,000 elephants have died in just the last three years. If this rate continues, African elephants could go extinct in a few decades.

Poaching has been on the rise since 2008; and in 2011 alone as many as 40,000 elephants died for their tusks. The new field census of carcasses provides the first assessment of just how bad such poaching has become in recent years. In Kenya, at least, the rate of elephant kills matched up almost perfectly with black market ivory prices, suggesting that as ivory gets more expensive, more elephants will be killed for their ivory.

Central Africa's forest elephants have been hardest hit. The known population is down more than 60 percent since 2002. And, in recent years, populations of their savannah elephant cousins have begun to decline as well. Poachers are killing off an intelligent fellow mammal species that mourns its dead, can recognize itself in a mirror and stands as the largest remaining land animal on the planet.

Since 2011, at least in Kenya, the killing seems to have slowed, perhaps because that's the year China began restricting ivory auctions. One solution might be to close all ivory markets entirely, at least in the short term. In the long term, the only answer is to slow the demand for ivory in favor of a demand for living elephants. Otherwise, this generation could be the last to see proboscideans walk the wild.