Silent assassin or scapegoat: Is the sparrowhawk really to blame for Britain’s vanishing songbirds?
Mark Cocker turns his attention to the surprisingly fast sparrowhawk in this instalment of his column, The Unloved Bird's Club.
I am guessing that any reader, who, like me, spends much of their spare time out amid nature, has come up short on one specific set of observations: the moments that a bird of prey captures its food. Even observing a kestrel as it drops onto a vole after hovering over the field is rare.
In 50 years of looking, I have never once glimpsed a sparrowhawk take a bird. I’ve regularly seen the moments immediately afterwards, when the deed is done and the hawk, with wings spread and cowling some poor casualty, has its claws embedded in vital parts. However, the precise second of first contact is unknown to me.
Readers who have witnessed it will probably have done so when they chanced to be seated by a window as a sparrowhawk visited their bird feeders. It brings the visceral moment to the breakfast table and it can be both shocking event and raw spectacle all at once. What such garden assassinations also bring to the fore is the entire hunting ecology of this raptor.
What sparrowhawks lack in size, they make up for in speed.
Sparrowhawks are relatively small birds of prey, lighter in weight than a merlin; the male sparrowhawk is lesser in size and wingspan even than a kestrel. What they lack in dimensions, however, they more than make up for in speed and the element of surprise.
Sparrowhawks are originally from wooded habitats, where they can swerve and jink unseen among the trees, often low to the ground when you glimpse them as little more than a grey blur fizzing past. They are now brilliantly adapted to suburban environments. I suspect they use hedges, fences and even our own buildings to blindside possible prey.
I recall vividly a friend describing how a sparrowhawk once flew in like a bullet, ran up the garage roof and then peered over its apex for any possible victim on the other side. These urban innovations in sparrowhawk behaviour have possibly been in play over the past 50 years.
It was in the 1970s that the species began a steady recovery in Britain from the dark days of DDT and other agrochemicals that had proved poisonous to several bird-eating raptors. At that time, there were about 17,500 pairs, but there are an estimated 31,000 today, with an inexplicable shallow decline in recent years. Some have observed the rise in the species and linked it to declines in a number of our songbirds, presuming a causal connection between them. For these reasons, they dislike the sparrowhawk and advocate for its control.
Research seems to show that starlings, house sparrows and blue tits have suffered at the beaks of sparrowhawks.
There are several simultaneous shifts in bird populations that counter any sweeping condemnation of the sparrowhawk. One concerns our blue and great tits, which, like the raptor, are woodland birds. In fact, the breeding cycles of all three are closely integrated, because at the very moment our woods are full of young, naïve tit fledglings, the sparrowhawk is feeding them to its own brood.
Yet, as the hawk population has increased, so, too, have both great tit and blue tit numbers (by 76% and 23% respectively), although the latter has experienced a shallow decline since 2008. What offers support for the idea that sparrowhawks may be influencing some of the birds visiting our gardens arises from long-term population studies conducted by the British Trust for Ornithology.
The organisation’s research suggests that there is a negative consequence of the raptor’s presence upon three routine attendees at bird feeders: the starling, house sparrow and blue tit. The first two are so reduced that they are now red-listed species. What the evidence seems to show is that gardens where sparrowhawks are present have smaller numbers of those three songbirds.
It may be direct predation, but it could equally be that those species are now coming less frequently to such places. It doesn’t as yet show any link at the wider level of national populations.
Our towns and cities operate as refuges alike for blue tits and sparrowhawks.
What is indisputable, however, is that both sparrow and starling declines have multiple antecedents, even if the intensification of our agriculture is the single most important underlying factor in a complex picture. What seems equally incontrovertible is a partial inversion in our expectations, whereby the open country is an impoverished place for wildlife, whereas our towns and cities operate as refuges alike for blue tits and sparrowhawks.
This feature originally appeared in the August 5, 2026, print edition of Country Life. Click here for more information on how to subscribe.
