Moreover, private gardens often provide extra resources for adult as well as juvenile birds in the form of artificially provided supplementary food, which is estimated to be present in nearly 50% of gardens, and is known to have beneficial effects for individual birds (Robb et al. 2008, Davies et al. 2009). Many householders also provide artificial nest sites for cavity-nesting birds, whereas suitable cavities for nesting may be scarce in the vicinity of other habitats (Davies et al. 2009). In areas where development leads to the loss of garden habitat, particularly in less deprived areas (Pauleit et al. 2005), these alternative habitat types may gain in importance.