Sweet. That’s a male Kestrel, our smallest falcon. They’ve been declining badly, but actually do quite well in the city because they’re cavity nesters and find spots in old building corners and rusted out mouldings. When I lived in Geenpoint I used to follow a family in the eaves of an old church building. They’re known for their hovering hunting style; Gerard Manley Hopkins’ poem The Windhover was inspired by the European version. Recent genetic studies have led to a reclassification in which the falcons are now considered closer to parrots than to other birds of prey.