A deadly disease that attacks water birds, known as Avian Botulism, is suspected to have struck at Bells Swamp on the Bridgewater-Maldon Road in Neereman, 10 or so kilometres from Maldon. Bird rescue teams, including Victorian Wildlife veterinarians and volunteer regional wildlife lovers, spent the weekend searching the swamp for dead and unwell birds.

Local wildlife carer and rescuer Sam saw a post on social media about dead birds found floating in the swamp last Tuesday. On first inspection, Sam thought he had found casualties from duck shooters but realised this was not the case after he discovered the dead and sick ducks. Since then, he has been searching the swamp every day to locate any further casualties. “So far, there have been up to 100 dead and about 20 sick ducks, including two sick Eurasian Coots,” Sam said.

The origin of this breakout is not yet known, but there is speculation that the recent floods and resulting effects of weather due to climate change could have played a part. Parks Victoria has placed signs around the area warning visitors of the dangers of the disease.

Last Sunday afternoon when the Times visited the site, there were 11 people, some with nets, some in kayaks on the water as well as wildlife emergency response teams at Bells Swamp. The volunteers came from all over, and the Times spoke to volunteer Tony Murphy, who came all the way from Brunswick to help. “I have a concern for the steep decline of water birds, and so it is important to help save the ones we have left,” Tony said.  Unfortunately, most of the volunteers returned to their jobs throughout the week, so it will be up to the Department of Energy and Climate Action to take over the rescue and clean up.

The disease causes paralysis in the bird’s feet and wings, followed by their neck muscles becoming weak, which causes them to drown if they are in the water. They are also vulnerable to foxes and other predators. The illness takes about 10 days for recovery with treatment. Sick birds are taken to the Melbourne Zoo, where they are cared for.

According to Agriculture Victoria, water birds eat plants and invertebrates, such as maggots, insects and worms, and in the process, ingest the botulism toxin released by the bacteria Clostridium botulinum.

During warmer periods of the year, when water and soil temperatures are also warmer, bacterial numbers increase. Feeding water birds bread can also increase the risk of them being affected by botulism.

Suzanne Hughes, Parks Victoria District Manager, told the Times, “We are investigating reported bird deaths at Bells Swamp Nature Reserve. At least 50 birds have been found dead, with further as yet unconfirmed reports being received. Samples have been taken for testing, and we expect to get the results early next week.

“While we are waiting for the results, Parks Victoria will put up signage at Bells Swamp to warn the public of the potential health risk. We ask that people stay away from the reserve until further notice.”

It is important to note that avian botulism outbreaks do not typically cause illness in humans. Consumption from infected birds or exposure of open wounds in contaminated water, however, could result in human infection. Pets eating infected birds could also be vulnerable. It is therefore best to stay away from Bells Swamp until the cause of the birds’ illness is confirmed. The Times recommends that you pay attention to the Parks Victoria signage at Bells Swamp!

This article appeared in the Tarrangower Times, 17 February 2023.