Sparrowhawks are specialist hunters of birds: more than 120 species have been recorded as prey, ranging in size from goldcrest to pheasant.
Despite this preference for feathered prey, they have been recorded taking a wide variety of small mammals, including bats captured in flight.
Many of their victims are plucked and eaten while still alive.
Sparrowhawks frequently fall prey themselves to goshawks, who will not tolerate the smaller birds in their territory.
Tawny owls are also major predators of young sparrowhawks.
Female sparrowhawks are typically 25% larger than males, but often twice as heavy.
Because of the size difference, male sparrowhawks court the females with caution, as the female can (and sometimes does) kill her suitor.
The female is dependent on extra food provided by the male to produce sufficient fat to allow her to lay eggs.
Contrary to popular belief, sparrowhawks do not control the numbers of their prey, but the numbers of prey control the number of sparrowhawks.
Sparrowhawks do ensure that the populations of their prey are healthy by weeding out the sick and unwary.
In medieval falconry, the sparrowhawk was deemed to be a bird for a priest.
In falconry the male spar has long been known as the musket. The name was later used for the small handgun used by soldiers (hence musketeers).
Sparrowhawks hunt by surprise, but frequently crash into windows when pursuing their prey, usually with fatal results.
Like all birds of prey, sparrowhawks are vulnerable to pesticide poisoning. The species was virtually wiped out in Eastern England in the 1960s due to DDT either killing them or rendering them infertile.
During the sparrowhawk's absence, no obvious increase appeared in songbird breeding numbers, nor was there an obvious decline when hawk numbers recovered.
Most young sparrowhawks will breed within 20km of where they were raised.
Birds which use the same nesting territory in successive years will usually also have the same mate.
British sparrowhawks are largely resident, but migrants from northern Europe both pass through and winter here.
A male sparrowhawk can survive for two or three days without food, but the larger female can last for up to six days.
While a male sparrowhawk does well to live to seven or eight, the female may survive until she is ten or 11.
Sparrowhawks gained full protection in Britain in 1961.