Swans’ serenity masks stress of Grand Prix
Albert Park’s iconic black swans may have ringside seats to the Australian Formula One Grand Prix, but a study led by the University of Melbourne has shown they don’t appear to be fans of the event.
Published in the journal PLosOne, the study revealed even though the swans showed no behavioural changes and they did not leave the site during the event, their stress levels were higher during the Grand Prix than before or after it.
Associate Professor Raoul Mulder from the University’s Department of Zoology led the study, the first of its kind to investigate the effects of the annual motorsport event, which creates intense short-term noise, on the resident black swans.
“We don’t know much about the effects of acute short-term exposure to stress on swans, but there is some evidence in other birds that it can be detrimental to lifespan or breeding success, particularly if it occurs early in life,” Dr Mulder explains.
He said understanding what effects such disturbances may have on the birds is essential for successful management of urban wildlife and the mitigation of any impacts.
Albert Park Lake is surrounded by the Grand Prix racetrack circuit. Over the four days of the event, the 160 resident swans on the lake share it with some 300,000 human visitors, and must contend with noise levels that can reach up to 120 decibels – equivalent to standing near the stage of a rock concert.
“Probably the most common question we are asked by the public is how the birds are affected by the Grand Prix,” Associate Professor Mulder says.
“It’s quite a difficult question to answer, because we know that disturbance can trigger many possible reactions, ranging from avoidance, to changes in behaviour or more subtle effects such as increased stress levels”.
By individually tagging the swans, the researchers were able to track the birds’ movements before, during and after the event, to see if any birds fled the site in response to the event. A network of keen ‘citizen scientists’ across Melbourne helped the researchers by reporting any tagged birds seen outside the park via the website myswan.org.au.
In addition to tracking the swans’ movements, the researchers monitored behaviour, body mass and particularly psychological stress, which they did by measuring levels of a ‘stress’ hormone, corticosterone, in small blood samples taken from the birds.
The study revealed that despite the increased levels of the stress hormone corticosterone measured in the black swans during the Grand Prix, they did not leave the site.
According to Dr Mulder, resident swans may have stayed despite the noise and stress because abandoning an established site in search of other suitable habitat was too risky or energetically costly.
“Often with animals, these decisions are driven by trade-offs,” he says. “It might be costly to stay but even more costly to leave, if leaving involves giving up hard-fought space in prime real estate”.
The research team hopes to gain a better understanding of these questions by continuing their work at the park.
“We hope to conduct longer term studies to monitor any possible effects with the continued permission of the Australian Grand Prix Corporation,” he says.
The work was funded by the University and conducted with the cooperation of the Australian Grand Prix Corporation, which gave the researchers access during the event.