05 December 2022 Lincoln researchers help solve kākāpō mystery

Professor Travis Glare co-authored a paper in Science Direct which looked at how, unusually, only a single fungal black mould strain caused a fatal mass aspergillosis outbreak, allowing it to be traced back to its source. Senior technician Jenny Brookes processed the samples for the study.

In 2019, during a highly successful nesting season, the outbreak affected 21 individuals and led to the deaths of nine, leaving a population of only 211 kākāpō.

Aspergillosis is a respiratory disease caused by the inhalation of spores from fungi. The lung physiology of birds makes them susceptible, and aspergillosis can affect otherwise healthy individuals when spore loads are high.

The study identified the possibility the strain was brought to the birds’ five offshore sanctuary islands by humans through supplemental feeding.

However, it also suggested the outbreak may have been a ‘black swan’ event, in which multiple variables combined to cause the disease.

"These may include a more virulent strain of A. fumigatus in the island environment, and a warm, dry summer favouring fungal spore production in soil and leaf litter, as well as causing dusty conditions that increase airborne spore densities," the paper stated.

Using whole-genome sequencing data to identify the strain and understand the epidemic allowed the researchers to suggest procedures to detect and mitigate such events in the future.

"For example, detection of potentially pathogenic Aspergillus isolates could trigger measures such as enhanced hygiene controls, limits on the movement of eggs, chicks and equipment among nests and islands, and widespread screening for Aspergillosis."

The paper also sounded a warning for the future.

"The warm dry summer conditions which may have contributed to this outbreak will become more common with global warming, making genetic surveillance for disease-causing strains a crucial tool for managing the conservation of threatened species."

View a Newshub item on the report here.

Lincoln University offers a soil testing service to determine the risk of aspergilliosis from environmental Aspergillus, aimed at kiwi breeding facilities.

PHOTO CREDIT: Chris Birmingham