Devastating effects of drought becomes clear Kruger

SKUKUZA – The drought is taking its toll on the Kruger National Park (KNP). This past weekend a visitor to the park was devastated by the sight of four dead hippos which had seemingly died because water, and consequently food, is running out.

Mr Ian McDonald is a lecturer in game ranging and wildlife management at Unigrad Lowveld and described the drought as a double-edged sword. “From an ecological perspective, it is a natural and important component of the ecology of savannas, but from the point of view of an onlooker, it is heartbreaking,” he said.

This past weekend US minister of the interior, Ms Sally Jewell, was on an official visit to the Kruger during which she was addressed on the extent of the rhino-poaching crisis. Mr William Mabasa, KNP spokesman, predicted that tens of thousands of animals would die. “For example, we have 48 000 buffaloes in the Kruger and may lose up to 28 000.”

Also read: Kruger getting house in order for severe drought

However, he stressed that scientific research indicated that water should on no account be brought into the park to keep animals alive. He said a process of “survival of the fittest” would mean that nature selected the healthiest gene pool for survival. This would mean that surviving animals were very strong, and the reduction in numbers would help retain a balance between the number of animals in the park, and the available natural resources.

Mabasa predicted what McDonald subsequently saw. “The hippos will begin to die first, because they congregate in the remaining pools of water, and defecate in the water, which contaminates it. Unless we receive good rain within the next two to three weeks, we will see deaths on a large scale.

“However, we will definitely not bring in tankers of water, as was done during the severe drought in the 1960s. That was not beneficial to the natural ecosystem in the long run.”

McDonald elaborated on the effect of the drought, saying that, “Savannas are unique biomes in that they depend on regular ecological disturbances, such as a drought, in order to remain biodiverse and productive over the long term. A drought results in the mortality of many animals (and plants to a lesser degree). Mortality resets the biomass of animals to a level the environment can cope with in its degraded state. It is thus essential for the long-term well-being of the savanna that the animal biomass is reduced so that it can recover once the drought breaks”.

He explained that drought has a negative impact on all herbivores, but some are affected more than others. “This relates to the animals’ diet, physiology, size, habitat selection and food preferences. In general, short-grass grazers like wildebeests survive droughts better than other herbivores of a similar size. Tall-grass grazers such as buffaloes fare worse because of the lack of food. Bulk feeders of low-quality vegetation, like elephants and white rhinos, also come through droughts with lower mortality rates.

“Most predators perform far better during droughts for obvious reasons. Species which occupy a broad ecological niche and are able to alter their diet and habitat preferences also cope better. A good example here would be impala, which shift from grazing to browsing and are adaptable to various habitats.”

McDonald confirmed that hippos are taking severe strain. “They need regular access to water and have high daily food intake needs. These dual stresses are currently causing many hippo deaths.”

He said that, in general, the overall condition of most animals in the KNP still appeared to be fair, but this would change dramatically if there is not good rainfall before the onset of the traditional dry season. “Buffaloes, too, are under great pressure. Lion predation on them is very high at the moment because they are weak.

“A buffalo contains a lot of meat and it comes at minimal risk of injury to the lion because of the reduced ability of the prey to defend itself in its weakened state.

“There are conflicting emotions when you stand looking around at what is a semi-desert landscape at the moment. But we must remember that drought is a regular feature of African savannas. It is a necessary occurrence in many respects, and ‘this too shall pass’. I have never known of a drought that has not been broken.”

He concluded, “Although emotional to witness the suffering and ultimate death of an animal due to drought, it is better to allow nature to select which animals will survive and which will succumb, rather than intervening by culling.

“Culling an animal is based on human perceptions of its ability to survive and sometimes nature surprises us and animals that we had no hope for, manage to pull through. These are exactly the ones we want to survive as their genetics will be passed on to successive generations.”