PARIS — The sparrow, once the exemplar of a commonplace bird, is becoming increasingly rare in France and other European countries. The fall of the house sparrow (Passer domesticus) has already been well documented in Britain, partly thanks to a campaign by The Independent. French ornithologists have now charted a steep decline in Paris and other French cities. There has been an even sharper fall in urban populations in Germany, the Czech Republic, Belgium, the Netherlands, Italy and Finland. As in Britain, where sparrow numbers are believed to have fallen by 90 per cent in the past 15 years, continental ornithologists can find no coherent explanation for the sudden decline. The mystery is especially deep in Paris, which is believed to have lost 200,000 sparrows – maybe one in 10 of the population – in the past 17 years. At the same time, the presence of somewhat more exotic ‘country’ birds in the capital – from blackbirds to jays, kestrels and swifts – has increased. The city’s Muséum d’Histoire Naturelle is so concerned that it has launched a campaign to capture, examine and ring Parisian sparrows to investigate possible causes for their falling numbers. […]