Summertime in northern Botswana is the period for dramatic thunderstorms and rain. It is also the season of heightened activity among many species, including insects such as the fungus-farming termites.
These termites, also known as macrotermes, live in mounds. Colonies comprise thousands of sterile workers and soldiers, and a queen and king. Aside from these castes, there are also multitudes of termites which are sexed, have wings, and play no part in the daily activities of the colony, such as gathering food *or* defending the nest. These are the alates, and they are potentially the next generation of kings and queens. Their role is to fly away from the mound, find a mate from another colony and start their own new colony.
Hard rain acts as a trigger in the life-cycle of the termites. Following a downpour, thousands of alates will be released from the chambers in which they have been kept and tended. They fly about weakly, and soon land on the ground, at which point their wings drop off. They set about seeking a mate by following pheromone trails. Once this has happened, the pair then find a place where the sand has been suitably softened by the rain and they dig a hole. The lucky pair now start breeding. They survive off the fat reserves in their bodies until their offspring are big enough to go out and start bringing food back to them. In this manner they become the queen and king of their own new colony.
This is an interesting story in itself, but there is far more to it than that. It is only when you see a full-blown nuptial flight of alates that you realise something of their importance to the whole ecosystem. They are a vital link in the nutrient cycle.
The termites in each and every colony feed on vast quantities of dead wood – and in northern Botswana there is no shortage of that. Within a short space of time that dead wood changes from something that is very difficult for most creatures to benefit from, to living, breathing tissue in the form of the termites’ own bodies. During the nuptial flights, there are literally hundreds of thousands, if not millions of termites in flight and at this time they are highly vulnerable. The volume of food that they represent is phenomenal and the vast majority of them are snapped up by other insects *or* by frogs, lizards, snakes, birds and mammals. This summer I even saw some young wild dogs feeding on emerging alates. Many migrant bird species depend upon these termites for the bulk of their diet when they are here.
The accompanying images may give some idea of what the termites get up to, but you really do have to see them swarming to believe it.