Shortage of nest sites in the UK continues to be a real cause for concern for ornithologists. Loss of traditional holes in trees and houses may be partly due to the explosion of interest in home and garden improvements as popularised by many of the TV makeover shows. Even House Sparrow, formerly one of Britain's commonest urban birds, is finding it increasingly difficult to gain access to its traditional nest holes under the now sanitised eaves of buildings. Recent studies by the BTO and others have also shown that House Sparrow numbers have declined nationally by more than 50% since 1968.

Birds will obviously happily use a nest box with a larger hole however, they are more likely to use a smaller opening for safety from predators.

* Will also nest in the special Schwegler Wren House.