In recent years, new oil installations have caused significant disruption in the region where addax migrate. That, coupled with a spike in poaching by soldiers guarding those facilities, is said to be the primary factor which have led species' rapid decline.
"We are witnessing in real time the extinction of this iconic and once plentiful species - without immediate intervention, the addax will lose its battle for survival in the face of illegal, uncontrolled poaching and the loss of its habitat," Jean-Christophe Vié, Deputy Director of the IUCN's Global Species Programme, said in the release.
Though there is hope that more addax remain uncounted, their population in the wild is still likely too small to recover on its own. There are a few thousand of these animals held in captivity throughout the world, however, some of whom could be reintroduced to North Africa.
Ironically, as Scientific America points out, addax can still be found by the hundreds on private ranches in Texas - where they are still being raised to be killed for sport.