British birds have their housing crisis

Press, 17 July 1980, Page 15

British birds have their housing crisis

By

GEOFFREY LEAN,

“Observer,” London

Britain’s birds are fac-. Ing a housing •.. crisis, b it on by Dutch elm disease .... .. .. ; Scientists are warning that several species, especially owls, will be depleted . because- so many birds are ; being 1 made, homeless. - Elms, were particularly important ’ nest i sitesbecause in. much of. Britain

they were the most common trees in hedgerows — often they were the only kind., . They also make good homes for birds that nest in holes. When the trunk or a main bough of an elm breaks off, the stub end often rots out inside the tree forming . a deep . hollow - and: these formparticularly desirable resi-

dences, open at the top but with strong living walls. No other tree produces such suitable hollows. Many,' particularly ash, have good holes Which are

useless as homes because they have no drainage, and get filled with water. Black poplars, produce big holes with good drains, but their walls are less strong. '

Surveys by the British Trust for Ornithology show that the proportion of barn and tawny owls living in elms has fallen by about half since the Dutch elm disease epidemic. In one area near Oxford, a survey showed barn owl numbers down by half since 1970. Tawny owls will use more open nesting sites if

they are forced to do so — but these expose the young birds to. predators and bad weather.

Barn owls are particularly endangered because their other main homes, old farm’ buildings, are becoming rarer, as barns are ’modernised or turned into country homes, Not only birds which nest in the deep hollows

are made homeless. Rooks which nest in large numbers in elm branches, are hard hit and birds of prey such as kestrels, which use old crows’ nests, are also in trouble.

Scientists say that this nesting crisis could be helped if people would stop cutting down dead elm trees.