Times are still tough for the browsers and grazers as it gets drier each day; even the Sand River is slowly trickling to a halt. There are some miracles standing out against the dull brown grass and leafless branches though. The Jackalberry berries and the Sausage Tree’s red flowers are some of the few that gift these animals, sustaining them through winter.
The Sausage Tree blooms now, before the first rains arrive, thus monopolising all the attention of pollinators and dispersers. It does not have to wait for rain as it has deep root systems that access ground water channels, enabling it to defy all the elements. At night the flowers open into a crimson red and as the sun rises, many of them can be seen below the tree, littering the ground. This in turn attracts many antelope species such as Bushbuck and Impala that actively seek the nectar filled flowers. Above, in the trees canopy, there are other animals attracted to these blooms. Brown headed parrots poke a hole in the base of the flowers drinking their nectar; Vervet monkeys and baboons feed on the whole flower. If you look closely these primates are also feeding on the caterpillars that are consuming the leaves, and at the same time bees work hard to pollinate the tree during the day and bats take over their pollination duties at night.
On the ground, hidden amongst the dense vegetation, lurk the opportunists. The abundance of fallen fruit act as a distraction while predators – particularly leopards – plan their ambush on various unsuspecting creatures. At night while the hippos go out to graze they come across the sausage fruits and feed on them when times are especially lean. As they continue along their path, they defecate the, seeds acting as dispersers as the seeds land conveniently in a compost heap.
In the late summer, another tree gives life – the Marula tree.
Standing tall, the Marula produces nutritious fruits whose flesh is a great source of vitamin C and at the centre of which lies a nut enriched with protein. This helps many herbivores and omnivores before the seasons change and resources become scarce. The Luna Moth is a perfect example of how reliant some animals are on some trees. The Luna Moth caterpillar not only feeds on the Marula leaves, but also builds a silky cocoon on its branches. Once the caterpillar has metamorphosed, it transforms into a green moth with a wing pattern that mimics owl eyes, and a tail of wings that look like leaf stems. It is well adapted to reproduce for just a few days and lay its eggs on the leaves of the Marula tree, starting the life cycle over again.
These trees not only benefit animals but also serve as natural remedies for various human ailments. The inner bark of a Marula tree can be made into a pulp which (ironically) can be used for instant relief from the stings of hairy caterpillars. Ancient African healers have been using pastes made from the sausage fruit to cure skin irritations and sun damage. Scientists have found that the effect the pulp has on the skin is due to sterols, which are naturally occurring steroids that can treat conditions like eczema. Maybe there is a link between hippos eating the fruit to help keep their skin protected against the sun or maybe it is just that the fruits are a necessary food source to sustain them until the summer, when the grass is in abundance?
It is important to be aware of how trees fit into the ecological cycle and, in light of the current fires burning uncontrollably through the Amazon, to remain aware of how our reliance on rainforests and trees is ever so important.