Following the relocation of six adult male elephants in September 2008, from Kruger National Park, Gorongosa National Park introduced five hippos from Isimangaliso Wetland Park in the South African province of KwaZulu-Natal on October 7, 2008.
The transfer of the five hippos – one adult male, two adult females, one adolescent female, and one young male – represents the first shipment of a group of 30 hippos offered to GNP by Isimangaliso along the Eastern Coast of South Africa.
According to the Director of the Department of Conservation, Dr. Carlos Lopes Pereira, the remaining hippos will only be introduced after a study shows that these first five hippos can cohabitate peacefully with the Park’s native population of hippos. This waiting period is necessary to ensure that the new hippos do not clash with the native population, as problems among the animals could lead to fatalities.
Hippos play a very important role in the rehabilitation and restoration of the entire Gorongosa ecosystem. In 1972 more than 3,000 hippos were recorded in the Park and in 2007 only 160 were found. Their low numbers are affecting the ecosystem because they keep grasses short and palatable for other herbivores that do not or cannot feed on very long grasses.
Historically the hippo population fed heavily on the grasses of the Urema floodplain. This helps to expand the area that gets flooded during the rainy season, promotes the retention of grassland, and fends off encroaching woodland. Despite spending much time in the water, hippos feed on land. They have muscular lips up to half a meter wide that enable them to graze a broad swath and harvest short grasses. They quickly consume 40 kilograms of grass at night with little noise. Hippos play an important role in the ecosystem, as they create important pathways to water sources for other, smaller animals.
Relocating wild animals, especially hippos, is a delicate operation that is logistically challenging. Because of this, every care was taken in order to ensure the survival of the animals in their new habitat.
The process of capture, transport and unloading of the animals generally went smoothly. However, one adult male hippo arrived at the Park with a slight injury. “When we let the animals go along the bank of the Sungué River, in the heart of the Park, we confirmed that one of the hippos had swelling in the left rear hoof. It got off the truck limping and went to submerge in the water, but it’s a minor injury. In fact, two days after unloading, the sick animal was still to be found somewhere near the place it had been unloaded, with progressive improvement of the swollen foot,” Dr. Carlos Lopes Pereira, Director of Conservation Services said.
The four other hippos were all healthy when unloaded and upon leaving the convoy they immediately moved calmly towards their preferred habitat. They drank water and immersed themselves for some minutes before leaving the water to feed on vegetation growing on the other bank of the river. Two days later, the relocation team returned by air to the release zone to confirm that the new hippos had followed the Sungué riverbed towards deeper waters. Presumably they had already joined the larger established group of hippos in Lake Urema.
The hippo relocation is part of the Gorongosa National Park Project’s goal to restore the Gorongosa ecosystem. Hippos, along with other important species, were seriously devastated by civil war and illegal poaching in the years that followed the General Peace Accords. Likewise, introducing hippos with different characteristics will improve the genetic pool of future generations because of genetic mixing that will occur between relocated animals and native hippos.
