Tree Sparrows a welcome sight

With a patchy distribution and an unobtrusive nature, the tree sparrow can be a difficult bird to connect with. A small colony which frequented a series of farm buildings near one of my regular haunts has been absent over recent weeks and I had been wondering if I would get to see the bird locally this year. It was a welcome sight, then, to bump into three tree sparrows near Middle Harling over the weekend. Walking off a farming estate I caught a soft disyllabic chirp that immediately made me think tree sparrow. Investigating the source of the call, I spotted the distinctive chestnut-capped form of a tree sparrow, tucked into thick cover towards the base of a tree. Two others sat on the other side of the road in the shrubby cover provided by the garden of the estate’s gatehouse. This was a quite unexpected encounter, not least because I have passed this spot many times over the past few years without hearing so much as a chirp.

The tree sparrow has probably undergone a greater decline over the last 30 years than any other British bird. Although widespread across lowland Britain at the end of the Nineteenth Century, its population has been in decline since the 1930s. A slight recovery during the 1960s was linked to an influx of immigrants from the continent but since then things have taken a turn for the worse. The arrival of immigrants late in the year no doubt contributed to the flock of some 1,500 birds which frequented the Eye field at Cley for three months during the 1957/58 winter – a record modern count for the county. Things are very different today, with just a few reliable sites scattered across the county where you can guarantee seeing the species. The areas around Ringstead/Choseley and around the Cressinghams come to mind.

As with other farmland seed-eaters, the decline of the tree sparrow has been linked to changing farming practices. The loss of over-winter stubbles may have reduced food availability and contributed to a potential fall in overwinter survival. However, the species may also be facing problems during the breeding season. Feeding its young on invertebrates, rather than seeds, may leave the species open to a decline in invertebrate numbers. Tree sparrows breed quite late in the year, with most initiating egg-laying during May. Individual pairs may breed through into August and beyond, attempting two or three broods through the season. This means that I will need to return to the gatehouse later in the year to see if these birds are here to stay or just wintering alongside the various finches and buntings that make good use of the area.