Our growing love of wild gardens may have led to a fight back for the sparrow Ornithologists say that the number of house sparrows appears to have stabilised after years of decline Pesticides,birds of prey and fashionable decking were blamed for numbers halving from around 12 million pairs in the 1970s to just six million today The British Trust for Ornithology thinks the trend of leaving patches of garden untended to allow nature take its course might have helped Intensive farming, pesticides and garden decking sent their numbers plummeting, but Britain's house sparrows seem to have pulled out of the dive. Ornithologists say that the number of house sparrows appears to have stabilised after years of decline. While it is not clear what is behind the reversal in fortunes, wilder gardens may play a part. Ornithologists say that the number of house sparrows (pictured) appears to have stabilised after years of decline. While it is not clear what is behind the reversal in fortunes, wilder gardens may play a part Pesticides, changes in farming practice, birds of prey and even the fashion for replacing lawns with decking were all blamed for numbers halving from around 12 million pairs in the 1970s to just six or seven million today. But a survey of garden birdlife by almost 15,000 members of the British public suggests that that numbers have stabilised at last. A spokesman for the British Trust for Ornithology, said: "The decline has levelled off." The encouraging news from the Garden BirdWatch survey is reflected in data from the wider countryside, the BTO said. Pesticides, changes in farming practice, birds of prey and even the fashion for replacing lawns with decking (pictured) were all blamed for numbers halving from around 12 million pairs in the 1970s to just six or seven million today The charity said the gregarious birds may have benefited from gardeners being increasingly reluctant to use powerful pesticides that kill the caterpillars they use to feed their young. With sparrows enjoying hiding in hedges and ivy, the trend for leaving patches of garden untended to allow nature take its course may also have helped. In contrast, the fad for covering over green space with decking may have been partly responsible for the decline. Clare Simm, of the BTO's garden ecology team, said: "We are a nation of wildlife lovers and more people are now managing their gardens for wildlife, which will be benefiting our house sparrows. There is also a greater awareness of clean feeding stations and in reducing garden pesticide use. The charity said the gregarious birds may have benefited from gardeners being increasingly reluctant to use powerful pesticides. With sparrows enjoying hiding in hedges and ivy, the trend for leaving patches of garden untended to allow nature take its course may also have helped The combination of these factors could be helping the house sparrow to maintain its population. To ensure numbers don't drop again, she advises those with bird feeders to keep them clean and free of mouldy food that can spread disease. Other tips include letting a patch of garden go wild to encourage insects and planting species such as hawthorn and ivy which provide thick vegetation for house sparrows to hide in. Having the biggest playlist doesn't make a male songbird the brainiest of the bunch. Researchers found that the best singers among a group of sparrows were the worst at food-finding puzzles. The study is the first to find that birds with an impressive selection of songs struggle in other areas. 'For songbirds, singing a lot of songs indicates a bird is smart, but that signal is not necessarily indicative of intelligence for everything,' said Duke biologist Steve Nowicki, who led the research. In a series of problem-solving tests with the birds, he and his colleagues found that the male song sparrows that sang the most songs learned to solve food-finding puzzles more slowly than the birds singing fewer songs. The researchers think that female song sparrows may use potential mates' songs to gauge both mental strengths and weaknesses. Nowicki and collaborators first measured the number of songs 14 male song sparrows sang. They then taught the birds to identify where a mealworm was hidden in one of 12 shallow wells on a wooden rectangle. The scientists put plastic caps over six wells so that the birds had to learn and remember spatially where the worm was on the wooden block. The birds that learned to solve the food puzzle more quickly sang fewer songs -- an observation opposite of what the scientists expected.