Woken by thunder about 2am. Lots of lightning and some serious rain. The first really good storm of the “build up” season that precedes the arrival of the monsoon from the north west. The “build up”, or kunumeleng in kundedjngenghmi language from Arnhem Land is a time of oppressive heat and humidity …temperatures mid to high 20s C at night and heading for 40 in the day. Many days watching storm clouds that tease but don’t deliver. After last night’s storm a drop in humidity and temperature…but just a temporary relief as we wait for the wet season. The image covers about 400km East/West.
It’s that time of year in Northern Australia — the temperature and humidity are rising and the Build Up (or kunumeleng in Bininj Kunwok) begins. The bush is preparing for the coming of the Wet (kudjewk).
One of the great seasonal events of this time is the eruption of swarms of flying termites. Winged female and male alates fly out of nests in coordinated swarms in the hope of meeting up after landing and founding new colonies.
I watched one of these events at Kabulwarnamyo on the Armhem Plateau. The workers built a hollow tower out of sand and soldier termites began to guard the structure.The winged alates began to pour out and upward, like a plume of smoke in the air.
In no time skinks were gathering to feast on the fat bodies of the fallen termites. They were soon joined by Grey Butcher Birds (Cracticus torquatus).
An analogy of termite colonies with plants is apt when it comes to dispersal, as like many plants they reproduce by allowing “seeds” to be dispersed — in this case the seeds are the winged male and female alates. Alates are generally poor fliers and do not travel very far — understandable given that male and female alates need to meet up and dispersal flights of more than a few hundred metres reduce the likelihood of this happening. It may also disadvantage a colony with significant genetic investment in adaptations to a local environment to have long dispersal flights that risk leaving that environment.
Northern Australia is a big country shaped in significant part by the termite. In many places the very look of northern savannas owes much to the mounds built by colonies of this insect. North Australian savannas have one of the most diverse range of termite mounds in the world: from the enormous buttressed “cathedrals” of spinifex termites, to the remarkably aligned “magnetic” mounds (pictured) and miniature cities of columns built by various Amitermes species.
Picture of swarm: Peter Cooke
Picture of magnetic mound: Pat Woolley
Source (in part): Savanna Explorer website