Is feeding ducks a death sentence?

Wednesday, 4 March 2015

Parkgoers could be killing birds with kindness during an innocent outing to feed the ducks.

Western Springs Park is experiencing an outbreak of avian botulism which can prove fatal for waterfowl due to paralysis.

Bread thrown into lakes and ponds by visitors wanting to feed the geese, swans and ducks contributes to the problem.

The toxin is not harmful to humans and is caused by a buildup of organic material in the water.

Signage is dotted around Western Springs Park asking visitors not to feed birds in the lake.

But Bird Rescue volunteer Heather White said people are either ignoring the signs or don't see them.

'Every visit I see at least one person throwing bread into the lake even when birds aren't in the vicinity,' she said.

The Auckland City Harbour News spotted two groups throwing bread into the lake during a visit last week.

Auckland Council local and sports parks central manager Jane Aickin said botulism incidents aren't recorded or monitored so it's difficult to know for certain if the signage is working.

'However, we believe our signs are clear and effectively inform people of the dangers of feeding the ducks in the water,' she said. 'The issue of feeding waterfowl in lakes/streams is regionwide so any signage review would need to be holistic.'

White would like to see larger, more prominent signs installed around the park, written in multiple languages to alert tourists.

Birds with botulism are unable to use their wings or legs normally nor control their eyelid or neck muscles.

Bird Rescue volunteer Virginia Nicol said birds with botulism can often be seen struggling to keep their heads above water and are unlikely to move when approached.

Senior freshwater ecologist Matthew Bloxham said the water quality in the lake deteriorates in summer when water temperatures increase and dissolved oxygen concentrations decline. The botulism toxin occurs in ponds during long periods of hot and calm weather.

The council is discussing the wider issue of water quality with the Waitemata Local Board.

White said this outbreak appears much worse than in previous years.

'The number of sick birds - mainly ducks - has increased dramatically,' she said. 'It's very frustrating knowing that it can be prevented if the public had a better understanding of the consequences.'

Avian botulism can be treated if the birds are caught early, she said.

'Sadly if they are showing signs of sickness and can't be caught then the next day they will most likely be too sick to be helped or will have drowned overnight.'

White would like to see visitors stop feeding bread to the park's feathered residents altogether. Overfeeding birds with starchy food can cause deformed wing growth, known as angel wing, preventing birds from flying.

Sick birds can be taken to the Green Bay Bird Rescue centre between 8am and 5pm. Phone 816 9219 outside of these hours.

Go to birdrescue.org.nz.