Science & Tech · Science & Environment · 2 hrs ago
Koalas near Newcastle show no evidence of chlamydia in tests
Researchers estimate around 2,300 koalas live in the Sugarloaf-Stockrington conservation area near Newcastle, Australia.
The estimate comes from drone surveys and modelling, after researchers confirmed 292 koalas in the area in late 2025.
Tests found no evidence of chlamydia in 27 wild koalas whose droppings were collected and examined.
A review of records also found no evidence of the disease in 27 other koalas treated or rescued within 30 kilometres of the area.
Chlamydia is common in koala populations in New South Wales, but these results do not prove every koala is disease-free.
Researchers say the population may be isolated and have low genetic diversity, which could help explain the findings.
They plan to monitor a wider area to learn more about the koalas' genetics and the population beyond its core range.
Researchers found no evidence of chlamydia in tests of 27 wild koalas from the Sugarloaf-Stockrington area near Newcastle.
A review of records also found no evidence of the disease among 27 more koalas from within 30 kilometres of the conservation area.
Drone surveys and modelling in 2026 suggested the area may have around 2,300 koalas.
The researchers say the population appears to be thriving, but may have low genetic diversity.
The study team has surveyed koalas in the area since 2020.
- Who
- University of Newcastle researchers, including conservation scientist Ryan Witt and Aboriginal lead Daryn McKenny.
- What
- Tests found no evidence of chlamydia in 27 wild koalas, and a review found no evidence among 27 more.
- When
- Testing and surveys were conducted through 2026; the records review covered October 2022 to September 2026.
- Where
- Sugarloaf-Stockrington State Conservation Area and the surrounding Lower Hunter region near Newcastle, New South Wales.
- Why
- Researchers investigated the koalas’ reproductive health after footage showed an influx of joeys.
This story does not have two clearly opposing sides.
Ryan Witt and his team have surveyed koalas across 23,900 hectares.
Wildlife rescue and clinical records from the Lower Hunter region were reviewed for evidence of chlamydia.
Researchers confirmed 292 koalas in the Sugarloaf-Stockrington area.
Drone surveys and modelling suggested around 2,300 potential koalas in the landscape, and researchers tested koalas for chlamydia.
- Koalas tested
- 27 wild koalas from the conservation area
- Additional records reviewed
- 27 koalas within 30 kilometres of the conservation area
- Estimated population
- Around 2,300 potential koalas
- Survey area
- 23,900 hectares
- Survey effort
- More than 250 nights since 2020
What people are saying
We found 27 wild koalas without any evidence of chlamydia at the time of testing.
We think we have around 2,300 potential koalas in this landscape.
We think they've been isolated from other populations for some time, which could be why they don't appear to have any disease.