Image: Dung beetle specimens in the QVMAG collection.
Research reveals significant differences in impact according to size, wing presence and functional group
A study of native dung beetles following the 2019-2020 megafires in northern NSW has found the impact of fire varies significantly according to the size of beetle, whether they are winged or flightless, and which functional group they belong to — tunnelers, dwellers or rollers.
Speaking at the 2024 Australian Entomological Society Conference in Hobart this week, QVMAG Senior Curator of Natural Sciences and report co-author Dr Alfonsina Arriaga Jiménez said it is important to understand how native dung beetle populations recover after fire due to the critical role they play in the ecology of native forests.
“Many people are familiar with introduced species of dung beetles, for example, on cattle farms around the country, but less familiar with our native Australian dung beetles and the incredible work they do," said Dr Arriaga Jiménez.
“By burying and consuming dung, they improve soil structure, recycle nutrients, disperse seeds and control pests. Dung beetles are such amazing creatures, they are my favourite insects,” she said.
“Through this research, we wanted to provide insights into the consequences of megafires on beetle communities and better understand how different beetles respond and recover.”
Image: QVMAG Senior Curator, Natural Sciences Alfonsina Arriaga Jiménez
General Manager Creative Arts & Cultural Services Shane Fitzgerald said QVMAG is an active research institution committed to participating in and contributing to public discourse based on knowledge generated by museum researchers.
"Research not only feeds into many aspects of museum operations including exhibitions, public programs, publications and documenting the collection, it can also inform societal responses to important issues facing local and global communities, including biodiversity loss, climate change and sustainability. This research is a good example of that," he said.
Dung beetles belong to the family Scarabaeidae, often called scarabs or scarab beetles. They are found in habitats from desert and grasslands to native or plantation forests, on every continent except Antarctica. There are more than 500 species of native dung beetles in Australia including around 10 in Tasmania, which have evolved to process marsupial droppings.
The study investigated the impacts of fire on native dung beetle communities across nine sites within rainforests and wet sclerophyll forests in three national parks: Mount Hyland, New England, and Nymboi Binderay. Each site contained three 50 by 50 metre plots in both burned and unburned sections for comparison. In each plot, traps baited with kangaroo dung, mushrooms and insect bait were placed for two consecutive 48-hour periods at three intervals between November 2021 and January 2022.
Impact varies by size and type
The research revealed significant variation in the responses of beetle communities according to size, wing presence and functional group.
Small and large beetles were more abundant and diverse in unburnt areas, while medium beetles showed the opposite trend. Flightless beetles were more abundant in unburnt areas, whereas winged beetles maintained similar numbers in both burned and unburned areas, showing the greater impact of fire on flightless beetles.
Some dung beetles, known as rollers, roll the dung into round balls which are then used as a food source or to breed in. Others, known as tunnelers, tunnel under the dung in the soil and then bring the dung into their tunnels. A third group, the dwellers, simply live in the dung or just below it. Of these functional types, tunnelers were more abundant in burnt areas, whereas dwellers and rollers preferred unburnt areas.
“We think that tunnelers are better protected in fires by their ability to retreat down the tunnels they have built and the fresh dung around them,” Dr Arriaga Jiménez said. “Overall, the research shows that most populations of dung beetles rebound quite quickly after bushfires – that’s good news for the recovery of affected areas.”
Dr Arriaga Jiménez is an entomologist and conservation biologist specialising in dung beetles, focusing on their biogeography, ecology, and behaviour. Before joining QVMAG, she held a postdoctoral fellowship at the University of New England, where she studied dung beetles and served as a lecturer in Entomology and Integrated Pest Management.
To read the conference paper abstract, visit: Native Dung Beetle Populations and Recovery in the Aftermath of 2019-2020