Bird of prey: Sparrowhawk numbers have increased since the 1960s as the numbers of songbirds declinedThe rising sparrowhawk population could be to blame for the dramatic decline in some of our best loved songbirds, a study suggests.
Researchers have found a link between the increase in the birds of prey since the 1960s and a fall in numbers of tree sparrows, bullfinches and reed buntings.
The study also found that rising numbers of grey squirrels and kestrels could also be contributing to the decline of smaller birds.
But it found no evidence that rising numbers of predators were to blame for 'large scale population declines' across all songbird species.
The number of such birds has plummeted by 40 per cent since the early 1970s.
Over the same period, some birds of prey have thrived thanks to conservation efforts and a crackdown on potent pesticides which poisoned large numbers of sparrowhawks in the 1950s and 1960s.
Although sparrowhawks can eat large numbers of young birds, charities such as the Royal Society for the Protection of Birds argue there is no evidence they are to blame for the 40 per cent fall.
Instead, they point to changes in farming - such as the switch from spring to autumn sowing crops, the loss of stubble over winter and the increased use of selective pesticides.
The latest report from the British Trust for Ornithology was the biggest study yet on the links between predators and songbird numbers. It pulled together observations from 200 sites between 1967 and 2000 along with reports from 2,000 volunteers between 1995 and 2005.
It found that for 22 out of 29 songbirds studied, there was no evidence that predators were responsible for falling numbers. 'For the majority of prey species examined, the study provides no evidence that population changes have resulted from changes in predator numbers,' the authors said.
However, the study found seven species - including bullfinches, tree sparrows and reed buntings - where rising numbers of sparrowhawks were linked to a fall in numbers. The report called for more research
source: dailymail
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