Study insights may save kākāpō from ‘crusty bum’

Relief may be in sight for kākāpō affected by an extremely painful disease, thanks to a University of Otago – Ōtākou Whakaihu Waka-led study.

Healthier kākāpō means better survival and breeding success, say researchers. Photo: Lydia Uddstrom

Exudative cloacitis, a debilitating disease which causes inflammation of the lower digestive and reproductive tracts, has been present in the critically endangered kākāpō population for about 20 years, but its cause has been a mystery.

For the study, published in Molecular Ecology, researchers used cutting-edge genomic tools to find the culprits – three bacterial species strongly linked to the disease.

Lead author Dr Rebecca French, of Otago’s Department of Microbiology and Immunology, says they think the bacteria are working together to cause what is colloquially known as “crusty bum”.

They found the bacteria likely come from external sources, such as soil or water, or cross-species transmission, highlighting the need to investigate the environment on the islands where kākāpō live.

“Because the kākāpō population is extremely small, it is highly vulnerable to random pathogen emergence and disease outbreaks.

“This particular disease has become an increasing threat to kākāpō conservation, with more cases across a wider geographic area being identified over the past four years,” Dr French says.

Senior Author Professor Jemma Geoghegan, also of the Department of Microbiology and Immunology, hopes the research will lead to more effective treatments, prevention strategies, such as habitat modification and biosecurity measures, and potentially development of a vaccine or immune-boosting medicine tailored to the bird’s unique physiology.

“Healthier kākāpō mean better survival and breeding success – a crucial step toward the long-term recovery of this taonga species.”

The study also highlights the power of advanced genomics techniques.

“When a disease emerges, it can be very difficult to determine what, if any, pathogens are causing it, especially in wildlife. The methods we used are great for solving these mystery diseases,” Professor Geoghegan says.

Dr French is particularly pleased to have been involved in this work.

“I’ve been passionate about kākāpō for many years, including spending time volunteering on the island of Whenua Hou for the Kākāpō Recovery Team, and it’s incredibly meaningful to be able to contribute to their conservation through this research.”