Predator and prey - how do sparrowhawks affect our garden birds?

Predator and prey - how do sparrowhawks affect our garden birds?

The good news is that scientists have done research into how sparrowhawks affect our garden bird populations and there is nothing to worry about! Sparrowhawks only take the weakest and most vulnerable birds which would most probably die of other causes such as disease and starvation. It is this predation which leaves behind the strongest and healthiest individuals to breed the following year which maintains healthy prey populations.


Male sparrowhawk at a garden bird table in winter - Photo Kevin Ingleby

How do we know this?

  • Small birds can bring up five to fifteen chicks in one breeding season. They have so many chicks to increase the chances of just one or two surviving as this is how many need to survive to keep the number of small birds the same. So, if a sparrowhawk takes just one or two birds from each family of each bird species there will still be plenty left. Those that sparrowhawks don't take will probably die of starvation or the cold and because there won't be enough habitat to support them all.
  • Scientists have found that even when sparrowhawks weren't hunting the small birds in an area there were just as many small birds as when there are sparrowhawks about. We know this as when there were very few sparrowhawks because of the pesticide problems there were no more small birds than there are now.
  • Sparrowhawks and small birds have survived side by side for hundreds of years before humans got involved and they are all still here today!