A "dying" sparrow has become the first of a series of installations in a new space at London's Tate Modern.
Created by Danish and Norwegian duo Michael-Elmgreen and Ingar Dragset, the stunned sparrow appears to be trapped inside the museum window.
In fact, the mechanical creature is the work of the animatronics team behind the critically-acclaimed BBC show Walking With Dinosaurs.
The artists said the bird's incidental appearance was part of their message.
"We found out that sparrows are called 'Cockney sparrows' in Britain and are a working class symbol," said Mr Dragset.
"We wanted to show that working class culture and working class pride is dying out, even though there are still as many poor people."
The installations, in the ground floor space that used to house the Tate Modern shop, will rotate every eight weeks.
All the artists are working with the theme The Public World of The Private Space, examining how "the human condition is altered by the public or private environment".
"When the artists came to us, it seemed quite perverse that for this inaugural project the whole space would be completely empty apart from this tiny bird in the window," said Tate Modern curator Susan May.
"People walking past outside can see this drama unfurling, or they might miss it. It really depends on how preoccupied they are."