National Park City's own WildHomes campaign and guide to gardening for Wild Londoners
https://www.wildhomes.co.uk/
Royal Society for the Protection of Birds, De Montfort University and Natural England research suggests paving over front gardens contributes to declining numbers of sparrows:
http://www.rspb.org.uk/news/details.asp?id=tcm:9-203663
University of Sheffield Biodiversity in Urban Gardens (BUGS) Projects: research into the biodiversity and conservation value of domestic gardens in urban areas.
The original BUGS project was a detailed investigation of the biodiversity and habitats in gardens in a single city (Sheffield), completed in 2002. The second project involved similar work across five cities in the UK and ran from 2004-2007. The projects focused on back gardens.
