Weekend Argus (Saturday Edition)
How animal food pyramid is affected
ZEBRAS and blue wildebeest will thrive on shorter grasses, while lions, leopards and hyenas will do well too. But long grass feeders such as buffalos, tsessebe, reedbucks and rare roan antelopes will struggle with the drought in the Kruger National Park.
That’s the verdict of Dr Eddie Riddell, the park’s manager of freshwater resources, who explains in the well-documented 1991/92 drought larger predators did well, but this was at the expense of smaller predators including wild dogs, cheetahs and jackals who they “outcompeted” for resources.
“Furthermore, the surviving buffalo were the strongest and most resilient and thus only the ‘best’ repopulated the park,” Riddell writes in the September/October edition of the Water Research Commission’s Water Wheel magazine.
The article predicts the unfolding severe drought could “hold far-reaching consequences” for the Kruger where already the summer rainfalls for last year and this were below normal across large parts of the park.
Extreme droughts could cause severe or longer term ecosystem changes, notes the article.
A common misconception is that animals die of thirst during prolonged droughts, said Riddell. “In fact, most starve to death after grazing has been depleted… Some animal and plant species flourish when plenty of water is provided, others do not.”
He said the El Nino-related droughts of 1982/83 and 1991/92 were the most severe droughts on record in the Kruger, characterised by below normal rainfall for two consecutive years – a scenario predicted for this year.
Guidelines include that water should not be provided in areas that are naturally dry.
The catchment areas of the five perennial rivers that run through the park, including the Luvuvhu, Letaba, Olifants, Sabie and Crocodile, all originate outside the park.
The article notes how a severe drought ”holds many consequences”. In March 1992, for example, the Sabie River, generally regarded as the most biodiverse in the country, was close to losing its status as a perennial river..
Riddell noted how there’ve been some “challenges” to meet the ecological reserve in the catchments of the Letaba, Crocodile and Sabie rivers, but that these have largely been resolved through collaboration with upstream users.