A new report has suggested that a drive for energy efficiency in British homes could be partly behind a decline in garden bird populations.
The British Trust for Ornithology (BTO) published its Bird Trends document, which summarises the population trends of 120 breeding bird species and uses data from volunteer surveyors.
It found that 28 species have been in decline over the past 35 to 40 years, including Grey Wagtails, Cuckoos and Skylarks. In particular, House Sparrow numbers have fallen by 70 per cent since the 1960s and Starlings and House Martins have also declined by around half.
The study authors said sparrows living in cities and suburban areas were faring the worst and partly attributed this to homeowners removing potential nest sites.
Paul Stancliffe, BTO spokesperson, told BBC News: "As people are becoming more aware and better at insulating their lofts they are inadvertently taking away little nooks and crannies which have historically been used by the sparrow to nest."
Other possible reasons for the population declines included reduced availability of food in winter and harsher weather conditions threatening normal breeding periods.
In contrast, 18 species including Magpies, Wood Pigeons and Jackdaws had demonstrated a doubling in population size within 45 years because they are more generalist and can capitalise on the conditions in their surroundings to survive.
The BTO recommended putting nest boxes with 32mm entrance holes up in order to create nesting habitats for the garden birds that are getting rarer in Britain, which should help to counter the effects of our energy efficiency measures.
Indeed, this is sure to be a good compromise for homeowners who don't want draughty gaps under their eaves but still want to support our nation's wildlife.
We have a range of these in stock at CJ Wildlife, including the Birch Log style for Great Tits, Tree Sparrows and House Sparrows, the Bedford with an oval hole and black roof and, of course, the House Sparrow Terrace, available in plywood or timber.
Providing mealworms during the breeding season has been shown to increase breeding success in House Sparrows and is another simple way of helping these endearing birds.