Activists have begun hauling bales of hay into Zimbabwe's struggling national parks in response to a drought that has already seen dozens of elephants starve to death.

Vets for Animal Welfare Zimbabwe, an NGO, had trucked 9,000 bales of hay to Mana Pools, a national park in the north of the country, Radio France International reported.

"Because of the drought, the pools are drying up and elephants get stuck in the deep mud. We try everything we can to get them out of it, but even after digging and pulling them out, they are often too weak to stand up," said Carole Deschuymere, a wildlife photographer working closely with VAWZ.

"A lot of baby elephants are being born prematurely, and the mothers don’t have enough milk to feed them. The zebra foals also are being born now. Without the hay they would all just die," she said.

Up to 20 elephants in the national park are believed to have starved to death in Mana Pools in the past month. Earlier the Zimbabwe National Parks Authority said at least 55 elephants had died in the Hwange National Park, 300 miles to the southwest.