Crest erect, plump-breasted, with manicured spurs and a deliciously dissolute tangle of tail feathers, Katharina Fritsch's Hahn/Cock is a startling blue presence on Trafalgar Square's fourth plinth. Squaring up for a light-hearted cockfight with the admiral on his column, Fritsch's sculpture is a strutting Napoleon giving Nelson the bird.  Intended as a comment on the masculinity and public pomp of the square, the sculpture has a dignity of its own. The scale and modelling and degree of detail feel right. It is irreverent, but so was Elmgreen and Dragset's Powerless Structures, Fig 101, the boy on a rocking horse that it has replaced.  The colour, somewhere between cobalt and ultramarine, has the zinging hue of a packet of Gitanes or the trademark blue of Yves Klein's paintings. Like Klein, Fritsch often drenches her work in a single colour: a yellow madonna; an art dealer scarlet from his head to the soles of his shoes; black rats.  Fritsch's almost matt blue cock is both lifelike and other-worldly. The shapes are good. It is great to walk around, and see silhouetted against the pepperpot cupolas of the National Gallery, and all that sober bronze and Portland stone in the square. It doesn't get lost against the backdrop of buildings and buses. The colour crows, but not the cock – which is a lot more fun to look at than Edwin Landseer's sluggish lions surrounding Nelson's column, exhausted by their burden of masculinity and from sitting there so long.  A French cockerel by a German artist in a square whose name is Arabic in origin (Tarf al-Gharb), and dedicated to Britain's victory over Napoleon in 1805, Fritsch's bird lends an egalitarian, Gallic confidence to a square I generally dislike. Somehow, it reminds me that we are in Europe, and the 21st century. It lightens the mood and lifts the spirit. It doesn't strain to look meaningful or relevant, and doesn't overdo it with the metaphors or the symbols. It has none of the dutiful gravitas of some previous fourth plinth sculptures. The bird remains itself, looking out over the square with a cocky, avian indifference.
German artist's giant blue bird is an irreverent Gallic riposte to the pomp and masculinity of Trafalgar Square