FILE PHOTO: A pair of hippos swim in the waters of St Lucia estuary, South Africa, April 12, 2006. REUTERS/Mike Hutchings/File Photo

LUSAKA (Reuters) - Zambia will begin a planned cull of around 2,000 hippos in May, a senior government official said on Friday, reviving a measure put on hold two years earlier amid protests from animal rights activists.

Zambia says its population of 12,200 hippos is too large for the water levels in the Luangwa river, where most of them live. The authorities say the river can only support around 5,000 of the animals and that relocating them would be too costly.

“The hippo culling will be done once the hunting season opens in May,” Tourism Permanent Secretary Howard Sikwela told Reuters by phone.

A contract for the cull was signed in 2015 but was put on hold for further discussion until the cabinet decided last October to revive it, Sikwela said.

British wildlife charity Born Free, which led the campaign against the cull in 2016, says Zambia’s hippo population was far smaller than estimated.

“The return of the cull is devastating news. Wild hippo numbers across Africa are under growing pressure.” Born Free said in a statement posted on its website last week.

According to the charity, there are at most 130,000 wild hippos across the continent.