Elephants are what is known as “preferential grasers” – that means they PREFER to eat grass when it is green, lush and palatable.
When green grass is all eaten off, or it dries off and becomes unpalatable, elephants will turn quite readily to “browse”(which, in the case of elephants, means not just green leaves but the bark of trees also). They also eat certain fruits (as you rightly point out). So, elephants are principally grazers during the rains and browsers during the dry season, and they will eat edible fruit at any time of the year.
In terms of competition with other animals in Kruger, therefore, they compete with all grazers during the rains – and into the dry season, too; and they compete with all browsers during the dry season. And they compete with monkeys and baboons and fruit-eating birds like hornbills and barbets whenever fruit is available to eat.
Since 1960, however, Kruger’s elephants have destroyed “more than” 95 percent of the national park’s “top canopy” trees; so, they have totally destroyed the entire woodland biome of the national park. And when most of the big trees had been killed off, 100 percent of the understory plant habitats that once thrived in the shade of those trees died off, too.
There are now no deciduous woodland habitats in Kruger National Park that have “continuous canopies” – which species like bush babies HAVE to have because when they come to the ground they are killed off by all sorts of small predators.
Continuous canopy habitats are those where small animals like bush babies, squirrels, snakes and chameleons can move through the woodland canopy, tree to tree, without having to come down onto the ground. Those continuous canopies are now all gone. The effect this has had on the national park’s biological diversity has been huge. And the disappearance of so many big trees – in which species like the Martial eagles and Ground Hornbills used to breed – is causing massive reductions in eagle and ground hornbill populations (which might even become extinct in the not too distant future).