Wildlife Profile - Cathedral Termite (Nasutitermes triodiae)
| Order: | Isoptera |
| Family: | Amitermideae |
| Genus: | Nasutitermes |
| Species: | triodiae |
These termites build some of the most spectacular of all termite mounds, reminiscent of the elaborate architecture of medieval cathedrals.
We have a wide variety in northern Australia, all performing an essential role in our overall savanna ecosystems. The culmination of the termite year happens with the release of the alates as the humidity reaches the right levels (usually around Nov-Dec-Jan). Mammals, birds, reptiles, amphibians & other invertebrates all feast on what could be termed ‘a giant recycling process’, the end product of which is alates which are almost pure protein. When this happens, the sudden availability of a rich source of protein stimulates predators to move into reproduction mode themselves. Without this huge annual process, which only termites can initiate, our whole savanna woodland system could collapse.
These events take place at the start of the wet season & boost the reproductive processes of nearly all our native frogs, microbats, Dasyurids, & so on. For example, male Frilled Lizards, after feeding heavily on emerging alates in the ‘build-up’ period (dry season-wet season transition), will rapidly change into bright breeding colours & begin displaying to other males. It happens on a massive scale and the significance of this seasonal ‘big picture’ chain-reaction is vitally important to the ecology of the tropical savannah of northern Australia.
Frilled Lizards are but a part of a massive seasonal process, which, unfortunately, the toxic cane toads are now disrupting in a major way. As a result, we have seen major declines across the vertebrate range in northern Australia in recent times. Frillnecks feed on native frogs but toad metamorphs are lethal to adult Frillnecks. It is a story that science is finding very hard to understand. In a strange irony, termites have facilitated the rapid spread of the toad, as they feed heavily on termite alates at the start of the season, breed explosively & then turn their attention on native frog populations in a variety of ways, mainly as food. It is very difficult to measure this impact, other than to watch the decline. I am not a scientist, but I spend most of my time in the bush observing & my interest is in the interface between humans & nature, particularly public awareness & education.
Ian Morris - naturalist and educator
Distribution
Cathedral Termites are found right across northern Australia
Ecology
Life cycle - The workers cut up grass stalks and store them in outer chambers of the mound. They forage from underground, radiating from the mound. As the mound is extended, the outer storage chambers are abandoned and filled in again with soil. The soldier caste defend the mound by ejecting a transparent, sticky substance to enmesh predators such as ants. The queen produces all the eggs for colony. New reproductive termites (alates) emerge from the ground in specially created ‘turret’.
Diet – Grass
Habitat – Open savannah woodland
Features – A mound lives from 50 to a hundred years and it is thought that a single queen lives for the entire life of the mound.
The mound provides a perfect home for the termite which requires the right level of warmth and humidity. The ultimate in sustainable climate control!
These and other species of termite are major contributors to the environment in the harsh very wet to extremely dry cycles of the savannah woodlands. By foraging underground for grass they create channels the enable the soil to retain moisture for longer and get moisture into the ground with early wet season rains.
When the alates (winged termites, reproductives) are released in the early wet season, they provide a food bonanza for many species of bird and lizard including the Frilled Lizard. There are hundreds of tonnes of termite per square kilometre in the savannah, providing a rich source of nutrient transfer in 'poor' soil conditions.
Magnetic Termite (Artitermes meridianalis)
These termites live in areas of wet season flood inundation, and can be seen in Litchfield National Park. They are built on a north-south axis, providing the maximum effective solar absorption. This enables the termites to maintain the consistent levels of warmth and humidity they require.
Sources – Termites of Northern Australia by Alan Andersen et al, my personal observations. Photos-Mike Jarvis, Ashley Maple
