How cathedral termites got to Australia to build their 'sky-scrapers'

They build among the tallest non-human structures (proportionately speaking) in the world and now it's been discovered the termites that live in Australia's remote Top End originated from overseas - rafting vast distances and migrating from tree-tops to the ground, as humans later did.

Mounds of the cathedral termite Nasutitermes triodiae at Litchfield National Park. Credit: Jan Sobotnik.

Referred to as "cathedral" termites, the Nasutitermes triodiae build huge mounds up to eight metres high in the Northern Territory, Western Australia and Queensland - 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 "Down Under", 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 Biology Letters.

Co-lead author of the paper from the University of Sydney, Associate Professor Nathan Lo, said although much was known about the functions of termite mounds - which include protection from predators - little had been known about their evolutionary origins.

A closeup of Nasutitermes triodiae. Credit: Toru Miura.

"We found that the ancestors of Australia's fortress-building termites were coastal tree-dwellers, which arrived in Australia by rafting long distances over the oceans from either Asia or South America," Associate Professor Lo said.

"Once 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 - human beings, whose ancestors lived in the tree tops some millions of years ago."

Associate Professor Lo, from the University of Sydney's School of Life and Environmental Sciences, said the mounds are an engineering feat when considered in comparison to the tallest structure on Earth - Dubai's skyscraper the Burj Khalifas.

"Given 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," he said.

Nasutitermes triodiae also at Litchfield NP. Credit: Toru Miura.

The paper, "Parallel evolution of mound-building and grass-feeding in Australian nasute termites," said ancestral wood feeders would likely have lost the ability to feed on wood as they transitioned to feeding on litter and grass.

"This group is one of the most ecologically successful groups of termites in Australia," the paper reads.

"We have shown that its capacity to disperse over oceans - and to repeatedly evolve the ability to build mounds and feed on novel substrates in the face of significant environmental change - appears to have been important in promoting this success."

read more "How cathedral termites got to Australia to build their 'sky-scrapers'"

5 Strange Defense Mechanisms in the Animal Kingdom

It’s surprising what some animals would do to save their own skin. With predators ready to pounce on them, these creatures have a very strange way of defending themselves and live to tell the tale.

Horror Frogs

With a name like that, you’d think that these frogs are too scary to actually have any other animals messing with them. Also known as hairy frogs, they would go as far as breaking their toe bones when they’re being threatened. These bones puncture their skin and turns into a set of claws that they can use to scratch predators. These frogs are basically nature’s version of Wolverine from the X-men. Researchers are not really sure with what happens to their bone-claws, but they suggested that once the frog relaxes, the bones would slide beck into their skin.

N. taracua and C. saundersi

There are just time when you feel like you could explode because of anger. However, two bug species actually does this in real like. The N. taracua, a termite found in French Guiana and the C. saundersi, an ant native in Malaysia actually do explode when predators come their way. Both insects have a small gland in their bodies that are filled with poison. The ants contract their abdomens which causes their poison gland to explode while the termites keep theirs in their backs like a backpack. Although they do die in the process, you can’t say they went down without putting up a fight.

Bombardier Beetles

Although it’s common for animals to excrete some kind of toxic or poisonous fluid to save themselves, the bombardier beetle shoots these noxious bodily fluids out of its anus. This beetle has two different glands, one stores hydrogen peroxide and hydroquinones and the other keeps a mixture of enzymes that causes the painful reaction. This reaction is hot enough to reach near boiling point.

Pygmy Sperm Whales

These adorable looking animals seem harmless and helpless to predators, but don’t be fooled, they actually have a trick up their tail which can save their lives. When threated by their natural predators, like orcas, they let out a dark colored fluid that comes from their anus. They use this like smoke screen. When the fluid is secreted, they use their tails to spread it around and make their escape.

Texas Horned Lizard

These lizards are well known for their strange defense mechanism that seems to have been taken straight out of a horror movie. They have the ability to increase the blood pressure around their head area which causes blood vessels around their eyes to rupture. This spurts out blood and other bodily fluids to a distance of around 5 feet. This does cause them to lose a third of their blood supply, but it’s enough to help them run off and survive.

read more "5 Strange Defense Mechanisms in the Animal Kingdom"