They are slaughtered for the ivory and sport hunting trades, or captured for zoos and circuses. Generations of orphaned herds have become broken, so unlike themselves -- now aggressive and depressed. Bradshaw and her fellow researchers have made a diagnosis that was once thought to be uniquely human: Post Traumatic Stress Disorder.
"To diagnose an elephant with PTSD is novel, but that's because we have denied elephants the capacity of having a mind, having emotions. All the neuroscience says, yes, it's there, and the behavior confirms it," Bradshaw said.
Bradshaw and her colleagues published these startling findings in the journal Nature.
"How an elephant can be traumatized is seeing, for example, their mother killed with a gun. It's a huge shock," Bradshaw said. "Being taken away from their family, taken away from the herd and put into captivity."
For many elephant orphans, surviving capture is only the beginning of their journey out of Africa, and into a new heart of darkness.
"The trauma stays with the elephant when they're in captivity. They adapt to the life. That's a survival mechanism. Just like human prisoners. Some people can survive, some people cannot," Bradshaw said.
Sheldrick said she has seen how the elephants change.
"When you look at a miserable captive in a zoo, you're not seeing an elephant. You're seeing a tragedy," Sheldrick said.
A tragedy for what elephants have experienced, such as dominance training sessions in some facilities, and what they have not: the space to roam without boundaries.
"One hundred miles is a little stroll to an elephant. You can never give an elephant enough space in a zoo. It's like putting a human being in a matchbox for life," Sheldrick said.
For the last 30 years Sheldrick has been rescuing baby elephants orphaned and traumatized by the bloodshed of poachers.
"When they come in, newly orphaned, they have nightmares at night. They wake up screaming," said Sheldrick, who has become a surrogate mother at The David Sheldrick Wildlife Trust in Nairobi, Kenya, her orphanage for elephants. "The elephants have been the greatest challenge that I've had to face. Because at any age an elephant duplicates a human. When you take on an elephant, it's actually a lifetime's job."
Sheldrick and her devoted team nurture the babies back to physical health by feeding them milk every three hours, and back to emotional health by teaching them how to play and bond with new friends.
The keepers even sleep with the orphans at night, becoming a surrogate human family so that one day the elephants will be strong in spirit, and ready to join wild herds again.
"They have to be psychologically sound, because the wild elephants don't want a problem," said Sheldrick.
But there are some babies Sheldrick can't save. Elsewhere in the world, nursing elephants are separated from their mothers, their spirits broken in secret training camps so they can be taught to give tourists rides.
For decades, animals in the entertainment industry have been made to perform behaviors never seen in the wild, and the weight of captivity is bearing down on even the mightiest of animals.
"They're essentially very gentle animals. So for an elephant to become aggressive and kill a human, you have to understand how badly he's been treated by humans to be able to pluck up the courage to do that," Sheldrick said.