Voracious grey squirrel 'is greatest threat to songbirds'

he grey squirrel and the domestic cat are preventing the recovery of Britain's songbirds, which were devastated by intensive farming and the removal of hedges in the post-war years, says a new report.






The report says that in areas of high grey squirrel density, 93 per cent of small bird nests are raided
Of the two introduced predators, the grey squirrel kills more young songbirds than the cat.

The findings of the report, commissioned by the charity, SongBird Survival, are likely to challenge the received wisdom about the decline in songbird populations since the 1950s and what has prevented many from recovering over the past 15 years when farmers have been using fewer chemicals and participating in green farming schemes.

The author of the report, Prof Roy Brown, of Birkbeck, University of London, estimates that overall some 180 million adult songbirds, or their eggs and young are killed by mammals every year - chiefly squirrels, cats and rats.

That is out of an estimated natural population of 260 million of the main 15 songbird species - blackbird, song thrush, blue tit, great tit, robin, skylark, meadow pipit, wren, dunnock, whitethroat, greenfinch, chaffinch, yellowhammer, reed bunting and corn bunting.

The report says that in areas of high grey squirrel density, 93 per cent of small bird nests are raided. Where this is combined with sparrow hawk activity, it can result in 100 per cent breeding failure and a loss of 85 per cent of adult songbirds.

Prof Brown, who reviewed a wealth of information on the causes of songbird deaths said yesterday: "It looks as if 60 per cent of all breeding activity is being knocked out by predation.

"I would say the problem is now predation - on a par with other factors that are still there."

Prof Brown accepts the results of the many research projects that have shown that the principle reason for the decline in the farmland birds over the past 40 years was agricultural intensification and the removal of hedges.

Yet he believes that it is wrong to blame the failure of songbirds to recover over the past 10-15 years exclusively on agriculture, at a time when green farming schemes and lower pesticide applications have done much to improve the food available for songbirds. He wants predation, by both mammals and birds such as sparrowhawks and kestrels, to be studied as a possible explanation.

He said: "If you've got somebody who is sick, who is diagnosed as having cancer, diabetes and a mild form of anaemia, you've got to deal with the cancer first, but if you don't deal with the other two the patient won't get better."

Prof Brown said the grey squirrel has adapted to the British environment and there is a very wide range of food it will take compared with the vegetarian red squirrel.

He said: "I've raised some questions which need to be looked at much more closely. If predators are having as bad an effect as that, then the answer is to look at doing something more systematic to restore the balance, certainly with mammals and possibly with birds of prey."

His study is likely to re-focus attention on the Government's abandonment of widespread programmes for controlling the North American grey squirrel, which has pushed the native red squirrel into extinction across most of mainland England.

Grahame Madge, of the Royal Society for the Protection of Birds, said: "Grey squirrel predation is something we at the RSPB - and the British Trust for Ornithology, English Nature and the Forestry Commission - are beginning to think is a problem.

"We know the problems for some birds - such as the corn bunting, yellowhammer and grey partridge is very specific to do with agricultural change and pesticides.

''But for hawfinch and a number of other species, the grey squirrel is one factor that has been identified as part of the problem.''



Max
http://squirrelproject.blogspot.com/