The Citizen Scientist Helping to Map Australia’s Biodiversity
When I sat down to speak with Thomas Mesaglio – on the Citizen Science Show Podcast – his enthusiasm for the natural world was immediately apparent. A lifelong nature lover, he has turned his passion into a career that blends citizen science with professional research. As a curator and moderator on iNaturalist, an engagement officer for the Atlas of Living Australia (ALA), and a PhD student at the University of New South Wales, Thomas has dedicated himself to improving the way we document and understand biodiversity.
His journey began in childhood, spending school holidays exploring the bush and beaches of North Haven, a small coastal town where his grandparents retired. Encouraged by his parents, he collected insects, skeletons, and all sorts of natural oddities, setting the foundation for what would become a career in science.
Now, his PhD focuses on improving knowledge of Australian plants by combining citizen science records with professional data. One of his key initiatives involves identifying plant species that have never been photographed in the wild. To address this, he created a public list of unrecorded species, encouraging everyday people to help fill in the gaps.
“The reality is, a lot of discoveries happen by accident, a person might just be out for a walk, take a quick photo, and unknowingly record something significant.”
iNaturalist and the Atlas of Living Australia
As a curator for iNaturalist, Thomas plays a crucial role in moderating discussions, updating taxonomy, and ensuring data accuracy. His contributions are voluntary, but he sees the platform as a vital tool for making biodiversity data accessible to both scientists and the public.
The Australian iNaturalist community has grown rapidly, now boasting over 10 million observations from 110,000 contributors. Despite Australia’s relatively small population, it ranks among the top contributors globally. Thomas attributes this success to a combination of rich biodiversity, a strong citizen science culture, and the accessibility of platforms like iNaturalist.
His work at ALA focuses on ensuring that biodiversity data is as accurate and useful as possible. He engages with researchers, conservationists, and institutions, helping them integrate and refine datasets.
One of the most striking examples of citizen science making an impact came in the wake of the devastating 2019–2020 bushfires. Thomas and his colleagues launched the Environment Recovery Project, encouraging people to document post-fire regrowth. Volunteers were asked to estimate fire severity and compare their observations with satellite data. The results were impressive—citizen scientists, with no formal training, provided estimates that aligned closely with professional satellite measurements.
But the power of iNaturalist goes beyond disaster response. Thomas shares a remarkable story about a citizen scientist who uploaded a photograph of an unfamiliar praying mantis. Expert Matthew Connors realized it wasn’t just a new species—it was an entirely new genus. Within 18 months, it was officially described as Inimia nat.
“This is why I love iNaturalist, it gives people the tools to contribute to real scientific discoveries.”
Identifications on iNaturalist work through consensus. Some species, like birds, can be identified within seconds. Others—especially obscure plants or insects—might take months or even years. Thomas has had records sit unverified for over five years before finally being identified by the right expert.
Finding critters at Citizen Science events
Citizen science events like BioBlitzes are another way people can engage. These gatherings bring together experts and beginners to record as many species as possible in a given location. Thomas encourages anyone interested in biodiversity to attend, as they offer a chance to learn proper photography techniques and gain insight from experienced naturalists.
For some, iNaturalist becomes more than a learning tool—it becomes a game. Thomas admits he has a competitive streak, regularly challenging friends to see who can record the most species.
“But even if you’re not competitive, every observation matters,” he says. “You don’t have to travel to the outback to contribute. Some of the most important records come from backyards and urban areas.”
He recalls a personal example. While cleaning his house, he noticed an unfamiliar fly on his windowsill. He snapped a photo and uploaded it to iNaturalist. Later, an expert informed him that it was likely not just a new species, but an entirely new genus. Unfortunately, because he hadn’t collected the specimen, it couldn’t be confirmed.
“It was a frustrating lesson,” he admits. “But it just goes to show—there are discoveries waiting to happen everywhere.”
For anyone looking to get involved, Thomas’s advice is simple: be curious.
“If you see something interesting, take a photo and upload it. It doesn’t matter if it’s a common magpie or a rare insect—every record adds to our understanding of biodiversity.”
Thomas encourages anyone with questions to reach out. He’s active on iNaturalist under the username thebeachcomber and is always happy to help new users navigate the platform.
As our conversation wraps up, it’s clear that Thomas’s passion is not just about data collection—it’s about fostering a deeper connection between people and the natural world. And with each new observation, that connection grows stronger.
You can listen to Thomas talking about biodiversity and curating iNaturalist on The Citizen Science Show Podcast.
