How cathedral termites arrived here to build their 'sky-scrapers'
Before designing one of the animal kingdom's tallest structures, common in Australia's Top End, ancestors of these termite fortress builders rafted from Asia or South America about 10 million years ago, research has found.
[Their] capacity to... evolve... in the face of significant environmental change, appears to have been important in promoting this [ecological] success.
Photos from Litchfield NP: Above: credit Toru Miura. Top of page: credit Jan Sobotnik.Â
They build among the tallest non-human structures (proportionately speaking) in the world and now itâs been discovered the termites that live in Australiaâs remote Top End originated from overseas â rafting vast distances and migrating from tree-tops to the ground, as humans later did.
Referred to as "cathedral" termites, the Nasutitermes triodiae build huge mounds up to eight metres high in the Northern Territory, Western Australia and Queensland â representing some of the tallest non-human animal structures in the world.
DNA sequencing found the forebearers, called nasute termites, colonised Australia three times in the past 20 million years or so and evolved from wood to grass-feeding as they adapted to significant environmental changes, including increasingly arid conditions and the conversion of woodlands to grassland habitats in subtropical savannahs and central Australia.
Now a prominent feature of the arid landscape âDown Underâ, the mounds house millions of termites; this study is the first comprehensive investigation of the evolution of the nesting and feeding of the extended family of termites, through the Australian refugee descendants.
The findings of the international research are published today in the Royal Society journal .
Co-lead author of the paper from the ±ŹÁÏÍő, Associate Professor , said although much was known about the functions of termite mounds â which include protection from predators â little had been known about their evolutionary origins.
âWe found that the ancestors of Australiaâs fortress-building termites were coastal tree-dwellers, which arrived in Australia by rafting long distances over the oceans from either Asia or South America,â Associate Professor Lo said.
âOnce in Australia, they continued to build their nests in trees, but later descended and began building mounds on the ground instead, paralleling the evolution of the other great architects of the world â human beings, whose ancestors lived in the tree tops some millions of years ago.â
Associate Professor Lo, from the ±ŹÁÏÍőâs , said the mounds are an engineering feat when considered in comparison to the tallest structure on Earth â Dubaiâs skyscraper the Burj Khalifas.
âGiven that a worker termite stands about 3mm in height, these mounds are in human terms the equivalent of four Burj Khalifas stacked on top of each other,â he said.
The paper, âParallel evolution of mound-building and grass-feeding in Australian nasute termites,â said ancestral wood feeders would likely have lost the ability to feed on wood as they transitioned to feeding on litter and grass. Â
âThis group is one of the most ecologically successful groups of termites in Australia,â the paper reads.
âWe have shown that its capacity to disperse over oceans â and to repeatedly evolve the ability to build mounds and feed on novel substrates in the face of significant environmental change â appears to have been important in promoting this success.â