Botulism kills O'Connor ducks

by Urszula Dawkins

April 9, 2008

BOTULISM appears to have killed dozens of wild birds at Frederick Baldwin Lake in O’Connor.

On just one day, April 9, the bodies of 22 native black ducks lay rotting around the shores of the lake, with at least one sick bird forlornly circling the lake’s small island.

Karen Pryce-Howells, from Native Arc animal refuge, said avian botulism outbreaks were seasonal, and many birds had died at Frederick Baldwin Lake over the past two months. She visits the lake regularly to rescue sick birds, which often recover if treated early enough.

 “The ones that have been coming in are the black ducks, all the native ducks, we’ve had a couple of coots…,” Ms Pryce-Howells said. “We’ve had a couple of swans, there’s been pelicans coming off from other lakes as well.”

The wildlife warrior said over-feeding of water birds was one cause of the problem. Bread and other foods sink to the bottom of local lakes, and help create an environment where bacteria flourish.

“The first sign you’ll actually see is that the birds are lower down in the water, or not being able to walk,” Ms Pryce-Howells said. “The final stage is where they actually can’t use their wings, they can’t lift their heads up and they can’t breathe because of the paralysis.”

Botulism outbreaks happen when there are too many nutrients in the water and warmer weather and evaporation increase their concentration, said Denise Crosbie of Cockburn Wetlands Education Centre.

“You can get a nutrient-enriched system in a natural wetland, but then man actually increases that,” she explained, “due to the run-off coming in, and that will be capturing fertilisers from lawns, oils and things like that from the roads.”

Local residents can help reduce contamination from water run-off, she said.

“People can ensure they fertilise their gardens with the [fertilizers] that don’t pollute the rivers,” she advised, “Often they’re written on the packet that they’re river friendly.”