Starvation Island in northern Zimbabwe is living up to its name for the first time in 50 years as rising lake waters have submerged grazing land for hundreds of animals, conservationists say.

Rescuers in Zimbabwe?are holding exhausted impalas by their horns just to keep their heads above water after the hungry, exhausted animals desperately tried to escape the flooded island.

Starvation Island was once a staging post for rescued animals, named after many perished from hunger there during the building of the massive Kariba hydroelectric dam.

Now Starvation Island has shrunk to about one-third of its original size after record seasonal rains from central Africa drained into the Kariba lake.

The five-square-kilometer island has become four dots of land in the lake, stranding hundreds of animals without enough to eat. At least 200 animals are in immediate danger of starvation.

"There is zero grazing and animals are starting to die," he said. Eight impalas, common medium-size antelopes, were stuck on the smallest dot surrounded by encroaching water, said wildlife guide Richard Vickery. Two impalas managed to swim to larger rocks nearby as their tiny refuge shrank. But "on Tuesday, more than 20 animals plunged into the water and seven of them drowned," Vickery said.

Some of the exhausted survivors swam to safety and others were assisted by a boat of rescuers holding them by the horns to keep their heads above water for the last stretch of their escape.

Elephants and some other animals have routinely swum to and from the island, but smaller species of antelope, kudu, buck, warthogs and monkeys either won't dare swim more than a few meters or are too weak reach the main lake shore about three kilometers away.

Funds are being raised by conservationists, including the SAVE Foundation of Australia, to take hay bales and food blocks to the animals that remain on the island.