Swift brick is a hollow construction brick containing a cavity, so that swifts can nest within them. [1] They were developed in response to a decline in swift populations in the United Kingdom, a likely cause for which is loss of nesting sites. [2]
Swifts are small migratory birds which predominantly reside in sub-Saharan Africa, but summer in temperate countries to breed. [3] The common swift historically nested in small cavities within cliffs and crags, but has adapted to Anthropocene conditions by nesting in nooks and cavities in the exterior of buildings. [4]
Since the mid-1970s, declining swift populations have been recorded in Great Britain, accelerating to an estimated 57% decline in abundance between 1995 and 2017. [5]
Swift nesting bricks are rectangular, hollow structures containing a small aperture for Swifts to enter and exit. They can be made of concrete, brick and concrete, or [Polyvinyl chloride|uPVC] with a polypropylene exterior. [6] [7] The bricks are designed for installation high up within the exterior of buildings. [8]
There is an active cross-party parliamentary campaign to make the installation of swift bricks compulsory in new building projects in the United Kingdom. [9]