Why are we going?

The easy answer, to me, is to say we are going to study ants. Do I need any other excuse? What do you mean this isn't enough of an explanation?

I need to tell you a bit of a story to explain some interesting aspects of the ecology of the area we will be working. Of the ~7000 species of flowering plants that occur in southwestern Australia, more than 1,500 species produce seeds that are dispersed by ants. Compared to other parts of the world, this is a high diversity of flowering plants and it is also a large number of plants that have ant dispersed seeds. In fact there is only one other place in the world that is comparable - the fynbos in South Africa. It is slightly richer than western Australia.

The plants having ant dispersed seeds is just one part of this story. Another part of this tale is what the plants are doing to get the ants to move their seeds around. The plants produces an auxiluarly structure, called an eliosome, that is attached to the seed coat. This structure is rich in some type of nutrients that ants like. Different plants produce different compounds but regardless of the "flavor" of a seed's eliosome, the plant is investing energy to produce a food reward for the ants. An ant that happens upon the seed will pick it up and bring it back to its nest. The eliasome is eaten and eventually the still intact seed is discarded. The ants then are providing a service to the plants by moving the seeds away from the parent. This is an example of a mutualism, where both species interact and benefit from their assocaction with one another. The specific ant - plant, eliasome bearing seed association is called Myrmechophory.

With this context, now I can tell you about the quest of our ant adventure in Australia - the study of Rhyditoponera violacea. This ant is very common in the Kwongan Heathlands habitat where we wil be working. In fact, work done in and around our study sites showed that 70% of the variation in seed movement is explained by R. violacea. When this ant is present it moves most of the seeds on the ground. Where this ant is not found many of the seeds are not moved at all. Other ants do take seeds but none are as important as R. violacea, at least in this area.

Maria and I will spend a month trying to learn all that we can about the basic biology of R. violacea. The pace and timing of its foraging, how big the nests are, the shape and structure of the underground nest chambers, how they throw out their seeds when they are done with them, etc. I know I will have a lot of fun. As for Maria, this will be her first foray into myrmecology (the study of ants). Perhaps after a month of digging in the dirt and playing with ants , she will shift her focus from those vicious pond critters she studies.

Dave