Ants are so commonplace in everyday life that they seem insignificant. But they actually play a significant role in nature.
One of the largest ants in the world, the giant ant (Dinomyrmex gigas) can grow up to 2.5 centimetres in length. In comparison, common black ants are only about one-tenth its size, while the bigger fire ants are just a quarter of its size.
Regardless, ants in general play an important role in our ecosystem. They loosen and aerate the soil, allowing water and oxygen to reach the roots of plants. They transport seeds for food into their tunnels; as they only eat a portion of the seeds, the rest sprout and become new plants. Ants are also a source of sustenance for many organisms higher up in the food chain.
Very little is known about the giant ant in Singapore. In the primary forests of Sabah, where 500 species of ants co-exist, it has been observed that giant ant colonies include just one queen (the sole mother) and many thousands of workers and soldiers that live in multiple nests 10 to 20 metres apart. It's important to compare these findings with the isolated population of giant ants in Singapore, and determine whether their competition and community dynamics differ. Given that only one queen reproduces in each colony, this means Singapore may contain relatively few breeding units, making them a conservation priority species.
Ant expert Christian Peeters, is leading a study on the territories and the multi-nest structure of colonies of the giant ant in Singapore. The study assesses the total number of colonies present in forest patches.
Fieldwork involves individually marking a large sample of workers and observing their activities between nests. Determining their pattern of food transfer makes it possible to identify queen nests and the extent of territories. Once identified, young, newly mated queens will be observed for their dispersal and founding behaviour. Doing so will help us gain a better understanding of how they reproduce.
In future studies, molecular markers may be available to understand long-distance dispersal and determine if local queens are outbreeding with foreign males originating from distant populations in Peninsular Malaysia, Sumatra and Sabah.
Wildlife Reserves Singapore Conservation Fund (WRSCF) supports Dr Peeter’s field research in Singapore, which has helped identify locations of giant ant colonies in the city-state and gain a better understanding of their foraging activity and nest structures.
Photo credit: Christian Peeters
Understanding the general biology of the giant ant will make it possible to plan an educational display in a zoological garden setting, and highlight the ecological importance of ants and other social insects.
The information gained in this study will be used to create a conservation plan for the giant ant in Singapore. Furthermore, understanding the colonial structure and ecological preferences of the giant ant will be valuable for managing these species in captivity and can be used for designing a live ant zone for Singapore Zoo.
This species is ideal for an educational display to raise awareness on the importance of ants. The giant ant is large and easy to observe, it has complex social behaviours and spectacular foraging activities, including the care of sap-sucking insects as a form of husbandry. Finally, giant ants are generally placid and don't sting, so they're considered safe.
In the long run, the study will also provide a better understanding of giant ant reproduction, which will be the basis of long-term conservation of viable colonies.