The number of Africa's critically endangered black rhinos has risen by nearly 800 over a six-year period, according to a new report by the International Union for Conservation of Nature (IUCN).

Key points: The rhino population grew 2.5 per cent a year between 2012 and 2018

The rhino population grew 2.5 per cent a year between 2012 and 2018 Poachers are the biggest threat to black rhinos

Poachers are the biggest threat to black rhinos But lack of habitat also poses increasing challenges

Conservationists have been trying to save the species, which has been driven to near extinction by poaching.

According to the IUCN, the black rhino population saw an annual growth rate of 2.5 per cent between 2012 and 2018, with numbers in the wild going from 4,845 to 5,630.

But the organisation also said it was a slow recovery and the species remained critically endangered.

The IUCN said it expected the growth to continue over the next five years.

Black rhino populations have increased over the past years due to conservation efforts.

Attempts to save the endangered species included relocating some individual animals from established groups to new areas to increase the species range.

Some rhinos have been moved out of their home ranges to avoid interbreeding.

In June 2018, a group of 11 black rhinos where moved to Kenya's newly created Tsavo East National Park, from Nairobi.

All 11 died, most from drinking saltier water than they were used to. One died after being attacked by a lion.

But Paula Kahumbu, the CEO of wildlife charity Wildlife Direct, said the main threat to the animals remained poachers, who targeted them for their horns.

"There are major challenges still facing rhinos today. The first is the demand for rhino horn in Asia. So long as that demand remains, the price will stay high and the incentive for poaching will continue across Africa," she said.

"The prevention of poaching requires very good intelligence, extremely good anti-poaching efforts, and that is expensive. It means that we have to have almost a military-style approach to protecting these animals."

The IUCN said overall poaching had decreased, with 892 rhinos poached in 2018, down from a peak of 1,349 in 2015.

However, one of Ms Kahumbu's main concerns is lack of space, as increasing human development encroaches on wildlife habitat.

"While numbers might be increasing, where will we put these animals?" she said.

"They need large and interconnected landscapes. At the moment, we have rhinos in small pockets.

"We have some protected areas, but we haven't got a strategy in Africa at this moment in time to secure continuous protected areas."

ABC/AP

