PLASTIC DEATH TRAP

In the park feeding the ducks this afternoon, when I saw one of them with a plastic multi-can holder firmly round its neck (thumbnail). It was feeding and moving around well enough to evade any attempt by me and a passing dog-walker to catch it, not that we had any tools that would have helped. He says he'll go back prepared tomorrow, and meanwhile I've posted photos on various local FB groups, hoping that someone will be able to do something about it.
NB: The Park is well supplied with litter bins.