No love lost between bowerbirds in quest for mate

First published 24 January 2012

Macho behaviour, jealousy and extravagant techniques to impress females is not limited to humans – bowerbirds display similar traits, a James Cook University researcher has found.

Professor John Endler, from JCU’s School of Marine and Tropical Biology, whose area of expertise is evolutionary ecology, has recently produced a research paper titled "Illusions promote mating success in great bowerbirds".

Professor Endler said his work investigated the function and evolution of animal signals and communication, and how it was influenced by the environment, and he uses it to predict the direction of evolution.

“My most recent bowerbird research is about how the visual design of bowerbird bowers work, how it is made by the birds, and what is its function,” he said.

Professor Endler, who also works at the Centre for Integrative Ecology at Deakin University in Victoria, said the research involved recording the geometric patterns of objects on the bower courts.

“I placed motion-activated solar-powered video recorders next to the bowers and recorded the behaviour and numbers of matings by the bower owner males.”

The research was conducted over several months at Dreghorn Station, a cattle station south-east of Charters Towers.

“The owners take extremely good care of their land, so it is full of wildlife as well as healthy cattle.”

Professor Endler said he was trying to understand the selective advantage of creating ‘false visual perspective’ for viewing by females, with objects carefully arranged according to their size, as they watch the bower-building male's visual display.

“I concluded males who build bowers with more effective false visual perspective, as seen by females, had more matings.”

Professor Endler said he was fascinated by the species.

“Bowerbirds are extremely interesting and intelligent birds, particularly the species I have spent most time on, the Great Bowerbird.

“They build bowers only for attracting females for mating; after mating the females go off to build a nest and raise young independently of any males.

“So the bower is nothing more than a complex visual signal to females and a mating place.”

Professor Endler said males also regularly stole each other's bower decorations and destroyed each other's bowers, something he said was akin to politicians sniping at each other.

“This means that I can make minor experimental manipulations of their bowers to change their visual signals, and this would be minor in comparison to what they do to each other,” he said.

Professor Endler said bowerbirds were native to, and found throughout most of Australia, but more species are found together in the wet tropics and wet sub-tropics.

The Great Bowerbird is found across the Top End, from south of Broome to south of Townsville and Charters Towers.

“I first worked on them on the campus of JCU Townsville and adjacent areas, but the most recent work is in a more remote area so that I can be largely independent of human-made objects, which the birds like to use in the suburbs.”

Contact details: Professor Endler, tel: 07 4097 6927 or 0488 255 712, or email John.Endler@jcu.edu.au

JCU Media contact: Caroline Kaurila (07) 4781 4586 or 0437 028 175.