The Barn Owl - some good news at last

Malcolm Ogilvie

According to the Hawk and Owl Trust, there are about 4,000 pairs of Barn Owls breeding in Britain. The Trust have just announced the results of the census which they undertook, together with the British Trust for Ornithology, during 1995 to 1997. Although this figure is slightly down on the total of 4,400 pairs found in the last census, carried out between 1982 and 1985, there seems little doubt that the long period of decline, going back to at least the 1930s, when there were an estimated 12,000 pairs (in England and Wales only, Scotland was not covered), has been halted and, in some areas, even reversed.

The Barn Owl has suffered, as have so many other birds, from the intensification of agriculture in recent decades. The rough field margins, which hold the mice and voles on which the owls feed, were ploughed up, while the amalgamation of fields through hedge removal reduced them even more. The now universal use of combine harvesters has done away altogether with the corn stacks, which once stood for many weeks in the farmyards awaiting the threshing machine, together with their populations of rats and mice. These animals have also been tackled with rodenticides which have, unfortunately, led to secondary poisoning of the owls. Old barns, and other farm buildings suitable for nesting, have in many cases either been pulled down or, almost as often, turned into houses. A knock-on effect of the removal of suitable hunting habitat around fields has led to the owls looking for food along road verges where they have proved particularly vulnerable to being killed by vehicles. Road casualties are now the most commonly reported cause of death in this species.

Attempts over many years to rear and release Barn Owls in order to restore their population were less successful than hoped, mainly because the habitat was no longer suitable. Breeding Barn Owls in captivity is comparatively easy and in the 1980s as many as 1,500-2,000 birds were being released each year. Sadly, though, this appeared to be having very little effect on the population. More recently, the main conservation effort has been directed at the provision of nest boxes to replace the loss of former breeding sites and the encouraging of farmers and land-owners to leave headlands and margins uncultivated. The extensive areas of set-aside on many farms have also proved helpful.

As the figures released by the Hawk and Owl Trust show, the population of Barn Owls in Britain is still well below its former level, but the fact that there has been hardly any further decline in the last 12-15 years is a great achievement in itself and is a cause for optimism that we will see an actual increase in numbers over the next period of years.

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