John Gould, who wrote The Birds of Great Britain, stated that the Peregrine, with its powerful pectoral muscles and long, pointed wings was admirably suited for rapid flight. It flew at a speed estimated at 150 miles an hour 'but this rate of progression is nothing compared to the impetuosity of its stoop when descending upon its quarry.'
In the background Wolf illustrated a dramatic stoop which Gould had seen while shooting in the Scottish Highlands. A Mallard pursued with 'meteor-like quickness' by a Peregrine was 'struck dead, its back being ripped open by a stroke of the Peregrine's hind claw.' Gould believed that this lightning strike in mid-air was the usual method used by the Peregrine for attacking its victim.
The female, shown about three-quarters life-size in the foreground of the illustration, is always larger than the male.