In this photo taken Tuesday, March 20, 2018, a small herd of elephants are seen from an airplane in Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

In this photo taken Wednesday, March 21, 2018, a team of wildlife veterinarians use a 4x4 vehicle and a rope to turn over a tranquilized elephant in order to attach a GPS tracking collar and remove the tranquilizer dart, in Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

In this photo taken Tuesday, March 20, 2018, two young elephants play in Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

In this photo taken Friday, March 23, 2018, wildlife veterinarian Ernest Mjingo, center, runs as an elephant starts to charge toward him after being darted with a tranquilizer during an operation to attach GPS tracking collars, near Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

In this photo taken Friday, March 23, 2018, wildlife veterinarian Justin Shamancha prepares to shoot a tranquilizer dart at an elephant during an operation to attach GPS tracking collars to them, in Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

In this photo taken Wednesday, March 21, 2018, a tranquilized elephant lies on the ground during an operation to attach GPS tracking collars in Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

In this photo taken Wednesday, March 21, 2018, a team of wildlife veterinarians prepare darts containing the elephant tranquilizer etorphine hydrochloride during an operation to attach GPS tracking collars to elephants in Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

In this photo taken Friday, March 23, 2018, a wildlife veterinarian stands over the trunk of a tranquilized elephant during an operation to attach GPS tracking collars in Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

FILE - In this Thursday, March 22, 2018 file photo, a Maasai herder drives his cattle across a pond as he returns from grazing them, near Mikumi National Park in Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

FILE - In this Thursday, March 22, 2018 file photo, Maasai youth herder Adam Rajeta, 18, carries one of his sheep back across a rickety wooden bridge as he returns from grazing them, near Mikumi National Park in Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

In this photo taken Wednesday, March 21, 2018, a herd of elephants form a protective circle against a perceived threat, just after one was shot with a tranquilizer dart during an operation to attach GPS tracking collars in Mikumi National Park, Tanzania. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)

FILE - In this Friday, March 23, 2018 file photo, young Maasai men relax and play a game of pool at a bar by the side of the road in the late afternoon at Mkata junction, near Mikumi National Park in Tanzania Friday, March 23, 2018. The battle to save Africa’s elephants appears to be gaining momentum in Mikumi, where killings are declining and some populations are starting to grow again. (AP Photo/Ben Curtis)