Whose dung is it anyway?

Artwork by Jay Hosler

Environmental DNA (eDNA) is defined as genetic material that is collected from environmental samples, such as soil and water. It is increasingly used for biodiversity monitoring. Recent studies have shown that invertebrates can also be used as samplers for biodiversity monitoring of vertebrate hosts. For instance, the blood in the guts of leeches or mosquitoes can be extracted and sequenced to determine the DNA of their hosts.

In a latest study with our collaborator, Rosie Drinkwater, we tested the use of dung beetles as samplers of mammal DNA. Specifically, we trapped Catharsius renaudpauliani dung beetles in Sabah, Malaysian Borneo, and then dissected out their guts for molecular analysis. Rosie found that the DNA inside the guts matched that of common mammal species in Sabah's forests, such as the bearded pig and sambar deer. How cool is that!

Catharsius renaudpauliani dung beetles (Photo by Chien C. Lee)

Apart from its use in biodiversity monitoring, identifying mammal DNA from dung beetle gut contents allows us to determine true feeding links between dung beetles and mammals. We can even construct interactions with mammal species that we cannot obtain dung samples to trap with. This will allow us to document other rare and elusive mammals that dung beetles rely on, such as those found in the canopy.

Moving forward, we aim to fine-tune and optimize this method further such that it can be used as a technique for rapidly assessing mammalian diversity in Southeast Asian forests, and aid future conservation efforts of rare and cryptic mammals in the region.

For more information on Rosie's work, check out the pre-print and write-up in Science!