Waterfowl in Wandsworth’s commons have decreased in the last five years, according to London Wildcare Trust.

The charity, which treats injured birds, blames a new a trend for capturing birds at night and taking them home to eat, although the council disputes its figures.

It comes just two weeks after a dog walker reportedly caught a man bundling a duck into a plastic bag on Tooting Bec Common declaring, “it’s free”.

Ted Burden, head of the trust, said: “People are taking them for their own table, or to sell on. They’re not taking them home to make pets out of them. They’re ending up in the cooking pot.”

According to him, sightings of this nature have rocketed in the last two and a half years, and Wandsworth Common’s mallards have decreased from around 50 to as few as 10.

But Peter White, bird recorder for both commons, disputed the figures and said natural predators were more likely to cause population changes.

He said: “There’s quite a lot of other factors. They can be taken by pike and large carp, herons or foxes. Dogs can also maim and kill the waterfowl.”

He added that in July, mallards often shed their feathers and go into hiding for a while to protect themselves from predators.

Councillor Sarah McDermott, executive member for environment and leisure, claimed there was no overall decline in the number of ducks, while the Parks Police said there was no concrete evidence of duck stealing.

John Bannerman, chief officer, said: “We have no reports to suggest this is happening.

“They [London Wildcare Trust] may be getting reports that we are not getting.”

Waterfowl theft is punishable by a fine of up to £5,000 and can be reported by calling 020 8871 7532.

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