Twenty-five years ago I used to spend hours devising ways of keeping house sparrows off my bird feeders. Today I would be delighted to see even one in my garden, as my last record of a house sparrow here at Bowbeck was in July 2006. That summer up to three birds appeared regularly, but not a single bird has put in an appearance since.  The decline of the house sparrow has taken place nationwide, though some areas have been affected much more than others. No one has come up with a reason, though numerous ideas have been put forward. These range from the introduction of unleaded petrol (the decline happened at the same time) to increasing numbers of sparrowhawks. However, sparrows have had to contend with sparrowhawks for thousands of years, so this in unlikely to be the reason.

Tree sparrows have declined even more than house sparrows, and this species is now regarded as something of a rarity in many parts of Britain where it was once common. Fractionally smaller than the familiar house sparrow, it has the same proportions and similar plumage. Look more closely and you will see that it has a smart brown cap and pure white side to the head, set off by a distinctive black cheek band. Unlike the house sparrow, both sexes look alike.

It differs from the house sparrow, too, in being a much more rural bird, quite at home in the farmyard, but not the city. The British Trust for Ornithology’s CBC (common bird census) has been monitoring tree sparrows for many years. Between 1972 and 1996, numbers slumped by a staggering 87%. If the decline had continued at this pace, then extinction in Britain would have been certain, but in recent years there have been signs that is making a significant recovery.

Britain’s tree-sparrow population has a history of decline and recovery, with the previous low point reached in the years following the last war. Then, in the late 50s, numbers started to rise again, peaking in the late 60s and early 70s.  A tree sparrow was the first sparrow I recorded at Bowbeck, on 21 October 2005, almost a year after we moved here. I didn’t see another one until a single bird appeared on my feeder this autumn. I’m hoping that it will become a regular visitor to the garden, and perhaps bring some of its friends.  

Though tree sparrows may be scarce in Britain, they are abundant in the Far East and China, where they take over from the house sparrow as the common sparrow. Millions were killed when Chairman Mao decided that they were pests and should be eradicated, but this action backfired, as the insect pests they controlled prospered in the sparrow-free countryside. Though seed eaters for much of the year, young sparrows are reared on a diet comprising largely of insects.David Tomlinson