Pigeons

Mr Onion Bag has a post (and some photos) relevant to this area about some cardboard pigeons, constructed under Vauxhall Bridge and speculation as to who put them there.

I passed under that bridge the other day and wonder the same thing, but I think that the cardboard pigeons look a little sinister. I wonder whether they actually work in deterring pigeons.

Does anybody else have any knowledge on who put them there?