Grey and barely noticeable in the rubble he calls home, this tiny bird is changing the design of city living.
The black redstart, who usually lives in the scree on European mountains, came to Britain after the Second World War, attracted to derelict bombsites of London and Birmingham.
But while the regeneration of the Gas Street basin, Moor Street and Snow Hill has been a boon for Birmingham, it has spelt disaster for the bird. As the developers moved in it was driven from each of those places it had made its own.
Now, just a handful of breeding pairs are left at Eastside.
In a bid to keep the existing birds there, the redstarts rubbly habitat is to be re-created on the £6billion development's roofs.
The idea took root and now all of new buildings on Eastside are to contain 'living roofs' - with wild flowers and greenery sown into the fabric to improve bio-diversity.
It means workers and residents can look out of their windows onto a panoply of living roofs - from those merely covered in lichen and succulents, to wild flower meadows and even trees.
Eastside sustainability adviser Rosemary Coyne says it is likely that in the future most new buildings in the city are built with them.
"It is a new dimension in improving bio-diversity," said Ms Coyne. "From an environmental planning point of view, they are great, especially where groundspace is at a premium."
Ms Coyne, of Groundwork Birmingham and Solihull, was gathering information on living roofs when she was seconded to Eastside and learned about the plight of the redstart.
Ms Coyne is hopeful that almost all of the 170 hectare development will encompass living roofs, whose benefits also include improved insulation and energy savings, better air quality and helping to reduce the risk of flooding.
"Roofs are quite depressing in Birmingham, they are all flat and grey," she said. " Anecdotal stories of people looking down on greenery suggests they work better and they have better recoveries from illnesses."
She said the plan was to provide a mix of habitats on low roofs and high rise buildings.
"For redstart habitat we will use rubble to simulate the hard landscape they like, undulating at different depths so there is more moisture in certain types of plant communities develop."