As they roam around the African savanna in search for food, giraffes and elephants alter the diversity and richness of its vegetation. By studying the foraging patterns of these megaherbivores across different terrains in a savanna in Kenya, scientists from the Smithsonian Tropical Research Institute (STRI) and collaborating institutions discovered that these large mammals prefer to eat their meals on flat ground, potentially impacting the growth and survival of plant species on even savanna landscapes, such as valleys and plateaus.
Megaherbivores are more concerned about eating as much food as possible while expending the minimum amount of effort, than about avoiding potential predators. Elephants may consume as much as 600 pounds of vegetation in a day; giraffes, about 75. This drove scientists to wonder about the impact of these megaherbivores on vegetation across a range of landscapes in the savanna.
"Previous studies have demonstrated that megaherbivores adjust their movement patterns to avoid costly mountaineering," said co-author David Kenfack, STRI staff scientist, coordinator of the ForestGEO network forest monitoring plots in Africa and recently elected Fellow of the African Academy of Sciences. "We wanted to know the extent to which fine-scale variations in topography may influence browsing damage by these charismatic megaherbivores and evaluate whether seasonal shortages in food availability would force the megaherbivores to venture into areas with rugged terrain."