Photographs of 80 young elephants being held in the national park show the elephants under "extreme duress," according to National Geographic. The elephants are only about 4 years old.

Joyce Poole, an elephant behavioral expert, told National Geographic that the elephants in the photographs appear to be afraid and stressed. "She is clearly frightened by what she sees, smells, hears on the other side of the bars," Poole wrote in an email, referring to a photo of a female calf.

"The calf with the flop ear appears to be a female and has a pinched face and lackluster skin," Poole told National Geographic. "She looks to be in mid-motion as if about to toss her trunk at something or to sniff the air."

As wildlife conservationists attempt to curb poaching, the export of young elephants could fuel demand for ivory in countries like China, but Zimbabwe's plan is legal under CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora.

According to Zimbabwe's The Herald, there are more than 80,000 elephants on its game lands and the 40,000 "excess" elephants are sapping resources like water that could be used for the country's people. Elephants could fetch an estimated price of $60,000 each. The Herald called the practice "better than culling."

Program Manager for Elephants Without Borders Kelly Landen wrote an email to National Geographic that said considering "present global efforts, campaigns and support to combat poaching, illegal wildlife trafficking and animal welfare, the world has remained largely silent about this, an issue that must be the most notorious case of wildlife abuse in recent history."

Saviour Kasukuwere, Zimbabwe's minister of Environment, Water and Climate, said last week that the money raised by the export of elephants would deter wildlife rangers from poaching because they would receive a salary, according to National Geographic.

Biologist and founder of Elephants Without Borders Mike Chase told National Geographic, "Capturing wild elephant calves is counter-intuitive to raising funds for conservation. It is a gross violation of animal welfare and might repel would-be visitors to a national park that has an exemplary ecotourism reputation."