THE Kruger National Park's oldest elephant, Duke, 55, has been fitted with a tracking device to monitor the animal as an endangered species in the park. Scientists have declared the ageing beast vulnerable to poachers.

Duke has already had close shaves with poachers in the park. The conservation authority said it had fitted a tracking collar to the animal to track its whereabouts in case it dies.

South African National Parks spokesperson Reynold Thakhuli said Duke was approaching his twilight years in the bush.

He said they would like to preserve his skull at the Elephant Hall Museum in the Letaba Camp inside the park.

He said Duke's remains would be used for research and showcasing the park's ability to protect its fauna.

"Duke has already lost both his tusks and he is also on his last set of teeth, which makes digestion difficult," Thakhuli said. He said the lost tusks, which weigh 30kg apiece, were fortunately found and would be placed in the museum.

An elephant's age is estimated by using measurements of shoulder height, tooth wear and hind footprint length, as well as dung bolus size.