LUWAI: What Does It Mean?

As teenagers, we often associate with different people than those we choose to be with as adults. At certain points in our lives, we may seek out subversive influences, while at other times, we prefer support and stability. The same concept applies to other partnerships in nature.

Take, for example, the whistling thorn acacia, also known as the Luwai tree by the people living in the Meru district of Tanzania. This African tree, a dominant species in the heavy-clay soils of upland East Africa, forms partnerships with four different species of ants. These symbiotic ants use the tree’s oversized thorny structures as shelter and nesting space.

The benefits for the ants don’t stop with just shelter. Not only do they get a place to stay, but they also receive food. Glands near the base of the tree’s leaves secrete a carbohydrate-rich nectar, which the ants can rely on as a substantial and consistent food source.

Some ants provide valuable services as bodyguards, even deterring elephants, while others have been labeled as freeloaders and parasites. However, these labels are overly simplistic. The mutualistic association between acacia plants and the ants is a prime example of symbiosis: the plants offer food and shelter in the form of food bodies, nectar, and hollow thorns, while the ants protect the plants from herbivores.

Recent scientific discoveries have shown that ants not only protect the acacias but also the birds that nest in these trees. Some tree-nesting birds prefer whistling thorns that house the most aggressive ant species, as the ants help protect the birds from tree-climbing predators.

Additionally, whistling thorn acacias are known as musical trees. They have hollow swellings at the base of some of their thorns. When the wind blows through these hollow structures, the trees produce a whistling sound.