Denis Summers-Smith, the sparrow expert, died on the 5th of May last at the age of 99.
Born in Glasgow, his childhood holidays were spent in County Donegal, where an uncle was a clergyman. It was there that young Denis first became interested in birds.
Summers-Smith took degrees in engineering and a PhD in physics. As an intelligence officer during World War 2, he surveyed coastal locations where the enemy might invade. These duties, no doubt, provided opportunities for bird surveys on the side. In June 1944, he was in the second wave landing on the Normandy beaches and was badly wounded during subsequent military operations. He became a Chevalier de la Légion d’Honneur in 2019.
Summers-Smith’s studies of sparrows began in 1947. The bird had received little attention from ornithologist up to then. Bird-ringers would release house sparrows they caught without putting rings on them, thinking it pointless to ring a bird which never went anywhere and about which, it seemed, everything was known. The recent history of the species shows how misguided they were.
Familiarity may breed contempt, but the humble house sparrow is the most successful of the world’s 9,600 wild bird species. Its modern career began in the settlements of early farmers in the Middle East, when sparrows began nesting around dwellings and eating the seeds of cereal crops. They never looked back; this bird has lived close to us since the dawn of civilisation, colonising every continent except Antarctica.
That the house sparrow, the ultimate stay-at-home bird, managed to spread so widely is most surprising. Of more than 6,000 rings recovered from dead sparrows in Britain and Ireland, only 3% of the wearers had moved more than 20km. Adults, always site-faithful, stay within 2km of home during their entire lives. Nor is this just a local trait; Summers-Smith noted that, at the onset of winter, sparrows living in Siberia tended to move into sheds housing livestock rather than fly to warmer climes.
The sparrow’s resourcefulness was demonstrated during the 1890s. As part of a crackpot scheme to introduce every bird mentioned in Shakespeare’s writings, sparrows were among 40 European species brought to America. Only two, the starling and the house sparrow, prospered in their new surroundings. Both have been so successful in the New World that they are now a nuisance in some areas.
But it has not been all plain sailing for sparrows. With the advent of intensive farming, the species almost disappeared from the countryside here and in Britain. It was business as usual in towns and cities until the 1970s.
Then urban sparrow population crashed, scientists being at a loss to explain why. When the London Independent offered a £5,000 reward to whoever discovered the cause of the problem, Summers-Smith agreed to act as referee. The sparrow’s hand-in-glove relationship with humans turned out to be the culprit. Pollution pesticides and chemicals had eliminated the insect larvae the sparrow nestlings needed.
Summers-Smith’s research was not confined to the house sparrow but extended to the other members of the sparrow genus. He travelled extensively in Asia Africa and the Middle East. His book The House Sparrow was published in 1963. The Sparrows appeared in 1988.