Scientists Puzzled as Endangered Birds Breed out of Season

Posted By : The Animal Facts Editorial Team

Date: January 6, 2022 10:59 am

A researcher holds a male purple crowned fairy wren at the AWCs Mornington Wildlife Sanctuary

Photo Credit: Wayne Lawler/ Australian Wildlife Conservancy

Scientists at the Australian Wildlife Conservancy’s (AWC) Mornington Wildlife Sanctuary are working to understand what gets the purple crowned fairy wren in the mood after they were found breeding outside of their widely recognized season.

Research on the species has been ongoing for 16 years at Mornigton Wildlife Sanctuary on Bunuba and Kija Country. For most of this time they have bred during the wet season from December to April. Over the past two years though breeding has been recorded during the dry season from May to November.

Dr Niki Teunissen, a Research Associate has conducted the on-the-ground research for the long-term Purple-crowned Fairy-wren project led by Professor Anne Peters of Monash University.

During her survey she noted that most adult females which were captured had brood patches, a bare area on the belly. This indicates that the females were breeding out of season.

“Successful breeding amongst an endangered species such as the Purple-crowned Fairy-wren is always welcome, however, we are surprised by the extent of dry season engagement,” said Dr Niki Teunissen, Research Fellow at Monash University. “We suspect that dry season breeding is a result of the above average rainfall we had last wet season which means water levels remained relatively high along Anie Creek and the Adcock River on AWC’s Mornington Wildlife Sanctuary. This may have provided good conditions for breeding. However, it does not explain why there was so much dry season breeding last year too.”

“To be honest, it goes against what we thought we knew about the birds’ breeding behaviour and we don’t quite understand the recent breeding activity by the wrens. It raises more exciting research questions for us to answer!”

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While the dry season breeding has led to increased curiosity among researchers it has provided a much needed increase to the purple crowned fairy wren population at the sanctuary.

AWC first acquired the sanctuary in 2004 and found the purple crowned fairy wren population in dire straits after wildfires and habitat loss caused by large herbivores. Conservation works by the AWC saw populations increase until 2018 when they unfortunately declined again due to drought and fire.

During November 2021 the birds were surveyed and it was found that the wren population stood at 204 individuals. This is up from 143 in November 2020.

The latest survey included 56 new birds which were mostly fledglings from the latest breeding season along with a few immigrants from other populations.

“It’s all really good news for the Purple-crowned Fairy-wrens at Mornington Wildlife Sanctuary,” Dr Niki Teunissen added. “We are really excited about this big boost in numbers and look forward to learning what our new findings may mean for the population moving forward.”

Learn more about Birds here – Birds Fact File | The Animal Facts

Learn more about the Australian Wildlife Conservancy on their website – Australian Wildlife Conservancy

A male and female purple crowned fairy wren are seen among vegetation

Photo Credit: Wayne Lawler/ Australian Wildlife Conservancy