Endangered Wrens Survive and Thrive After Flooding

Australian Wildlife Conservancy (AWC) have announced that purple-crowned fairy wrens in northern Australia’s Kimberley region have not only survived but are thriving after significant flooding in the region earlier this year.

“Although the fairywrens have taken a bit of a hit from the flood, they are doing well considering,” said Ian Hoppe, Monash University PhD student. “About three quarters (74%) of the adult birds that were present in a census of the population at the end of 2022, just before the floods, are still alive now. This survival rate is lower than we usually observe over the November to May time period, however it is not as devastating as we might have expected from such an extreme flood event.”

Monash University PhD students Ariana La Porte and Ian Hoppe returned to Australian Wildlife Conservancy’s (AWC) Mornington-Marion Downs Wildlife Sanctuary (on Bunuba and Kija Country) briefly in May 2023 to continue an 18 year study on the species led by Professor Anne Peters. This was their first trip to the sanctuary following an evacuation due to flooding in early 2023.

During January 2023 the sanctuary was thrown in to a state of emergency as ex-tropical cyclone, Ellie inundated the region with record flooding. AWC staff and visitors were evacuated from the site by helicopter. In the months since teams have returned to the site and begun the task of restoring damaged areas. These works included restoring road access, electricity and water facilities which has enabled more staff and researchers to slowly return and resume important conservation activities. 

The latest trip to monitor the purple crowned fairy wrens estimated the population to be at 242 individuals in May 2023, a slight decline compared to 256 birds in November 2022 (one month pre-flooding). 

Excitingly 24 out of the 67 breeding groups in the population had fledglings, young free-flying birds that were being fed by the adults. With all active nests having been washed away in the flooding this was an important discovery. Some groups were still breeding in May a month past the end of the typical breeding season.

“Although surprising to see that the birds are still breeding this late in the season, we’re not entirely shocked,” Dr Niki Teunissen Associate Researcher explained. “We have noticed that in wet years birds often keep breeding for longer. Presumably this is partly because in very wet years, floods frequently wash away nests, and birds don’t breed successfully until later in the season.” 

The 2020 Action Plan for Australian Birds identified the impact of increased flood frequency as a medium-level threat for this species, which warranted further research as a high priority. These birds are further affected by habitat degradation and inappropriate fire regimes.