Spider web DNA opening a new window on wildlife research

Spiders might be silent heroes in helping us understand and keep track of animals, with new Curtin research revealing their webs act like natural traps for tiny bits of environmental DNA (eDNA) from vertebrates.

This could change how we learn about wildlife, the Curtin University article says.

The groundbreaking study analysed 49 webs from a wildlife sanctuary in Perth’s hills and at Perth Zoo and identified the genetic signatures of 93 different animals, from birds and native mammals to meerkats and elephants.

Lead author PhD candidate Joshua Newton, from Curtin’s School of Molecular and Life Sciences, said spider webs might be a clever way to keep an eye on what animals are around us.

Spider webs are not just beautiful, they could be our secret weapon to better understanding nature.

“Our study shows that these webs can help us keep tabs on different animals without disturbing them,” Mr Newton said. ”Often overlooked in biodiversity studies, the webs proved to be reservoirs of genetic information.”

Environmental DNA is composed of miniscule fragments of DNA left behind by organisms in the form of shed skin cells, hair or bodily fluids and the spider webs act as passive biofilters.

“With only trace amounts of DNA needed to identify animals, this cheap and non-invasive method could be a game-changer in how we explore and protect our terrestrial biodiversity.”

Research supervisor Professor Morten Allentoft, head of the Trace and Environmental DNA Laboratory (TrEnD) at Curtin’s School of Molecular and Life Sciences, said the research may pave new ways to survey wildlife in challenging and inhospitable environments.

“Our initial results from Perth’s hills were promising with a bunch of local wildlife detections, but the true potential unfolded when we repeated the sampling in Perth Zoo and suddenly got giraffe and rhinoceros DNA in the spider webs,” Professor Allentoft said.

“Scientists typically rely on direct observations to study animals, but this research widens the scope of eDNA-based biodiversity monitoring. Our results even identified invasive species such as red foxes, house mice and black rats, showcasing the potential of spider webs as tools for ecological monitoring.”

The full research paper ‘Spider webs capture environmental DNA from terrestrial vertebrates’ will appear in the journal iScience.

Mineral Resources Limited funds the ‘Development and application of eDNA to biomonitoring of terrestrial fauna’ research project, from which this study is the first research output.