Local study determines the role of dung beetles as sensitive ecological markers
The field work of a Namibian scientist has helped to put the humble dung beetle in the spotlight as a sensitive indicator of the state of ecosystems across various biological niches.
When Heather Nependa had to draft a title for her research for a Masters in Entomology at the University of Stellenbosch, she chose dung beetles for their close association with and dependence on other larger animals, mostly mammals, and only later realised that they are also a robust detector species to determine the health of an ecosystem.
Finalising her research framework, she and her study leader decided on the title ‘Dung beetles as indicators of ecological disturbance in Namibia across a resource and land-use gradient.” Her intention was to demonstrate “how delicate our ecosystems are and how the disruption of one thing can permeate through entire ecosystems.”
Although she was completely hooked on the dung beetle topic, she faced an important obstacle when it came to field work. Very few organisations were interested in helping her financially.
“It is difficult to secure funding for a project like this that does not focus on a charismatic and appealing species,” she said, adding that eventually it was Nedbank through their Go Green Fund and their holistic approach to sustainable development, who stepped up to the plate and helped her to get her research going. This then opened an amazing world to her.
Early on in her work, she noticed their is a correlation between other biological factors and the density and distribution of different types of dung beetles. Dung beetles do not only collect dung, in doing so they also help to disperse seeds, and clear the bush of dung, in the process putting crucial nutrients back into the soil. They are nature’s Number One recyclers.
“Though their lifestyles are strange and maybe a little nauseating, the work they do is crucial to the function of ecosystems,” she said.
“They are an environmentally sensitive species and are highly affected by plant density and diversity, and also importantly, to dung resources. This means that they give an indication of habitat quality and how environmental change is impacting landscapes. Besides clearing dung, the actions of these animals have considerable ecological importance. Apart from measuring the impact of climate change, studying dung beetles could also be a good way to measure whether current conservation efforts are effective,” she said.
Nependa’s research project is exploring and evaluating the effects of land-use changes which require comparing a natural landscape to modified areas such as farms, by analysing dung beetle diversity and abundance. Initial observations indicate that disturbed land like farms and agricultural plots, carry less diversity and smaller populations while protected areas show a higher number of species and higher population densities. For instance, she noticed that one clump of elephant dung may attract several thousand dung beetles in only a short period of time.
Her field work also lead to some local discoveries as she found several species previously not thought to occur in Namibia.
To date, only a few studies have looked at dung beetles and their overall status, diversity and ecology in Namibia. Nependa’s work has already begun to expand the limited knowledge of these insects.
Caption: The ubiquitous dung beetle has far more to offer than only amusing tourists when they pursue their obnoxious fare. They are sensitive indicators of the well-being of ecosystems, and despite their numbers, they face several threats. The large Copris dung beetles are killed by the hundreds when they fly into flood lights at night, and they are prone to lice infestation, which can be seen here as a small white speck immediately above the leg on the left. (Photograph by Heather Nependa)
