For many years, man has given the peregrine falcon (Falco peregrinus) a hard time. From the late 1700s gamekeepers, custodians of the shooting estates, regarded the peregrine as vermin and shot or trapped them whenever they were seen over the red grouse moorlands of the north, and pheasant or partridge grounds further south. The first ‘Wild Birds Protection Act’ was passed in 1880, but the peregrine was not on the schedule of named species. Later Acts gave some degree of legal protection, but were generally ignored by the gamekeepers. The new ‘Protection of Birds Act’ of 1954 included total protection for the peregrine and its eggs for the first time, and marked the dawn of an era of greater public concern for wildlife conservation in Britain.
From around the 1840s, egg collecting became a fashionable pastime and peregrine’s eggs were sought after as a prize item for any collection due to the rarity of the bird and the attractive and variable colour of the eggs – cream with heavy red and brown markings. As an example, photographs exist in London’s Natural History Museum of one Dorset collector with 64 eggs taken from local peregrine nests in a single year. ‘Egging’, although illegal since the 1954 Act outlawed the practice, still continues today.
Domestic pigeons, bred from the wild rock doves, have provided a huge population of feral pigeons. The peregrine’s predilection for domestic pigeons caused it problems in WW2, when in July 1940, the ‘Destruction of Peregrine Falcons Order’ came into force. The need to protect carrier pigeons made it lawful for any authorised person to kill peregrines and destroy their eggs in order to protect the pigeons. The Order remained in force until 1946 and resulted in the shooting of almost 600 adults and immature birds, mostly on the south coast, with many eggs also destroyed. The slaughter reduced the peregrine population to around half its pre-war level, with the bird virtually eliminated from some southern counties. Post-war, peregrine numbers began to revive and almost reached pre-war levels, when another disaster occurred.
The introduction of organochlorine pesticides such as DDT in the late 1950s that were sprayed on freshly-sown seeds as a protection against crop pests, not only killed the pests, but the seed-eating birds – finches to pheasants. Predators such as the peregrine died after ingesting the still highly active pesticide residues in the bodies of their prey. A side effect of the poisoning was the thinning of the peregrines’ eggshells, so of those birds that did manage to lay eggs, many suffered failure due to egg breakage. Peregrines therefore died, clutches were reduced, and brood sizes fell from 3-4 eggs, to 1-2.
The ‘Silent Spring’ effect is well-documented; suffice to say that by 1961 the peregrine population plummeted to around 40% of its pre-war levels and only 68 pairs were known to rear young. It is thought that if this decline continued unabated, the peregrine falcon in Britain could have been extinct by 1967. However, it was that year that signs of a hoped-for recovery appeared following restrictions on pesticide use, and the 1971 survey showed the population had increased to 54% of pre-war levels, with successful breeding up from 16% to 25%.
Since then, peregrine numbers have continued to slowly recover, and by the late 1990s had reached pre-decline levels over much of their former range. However, in southeast and east of England recovery has been slow, and the range is now contracting again in northern Scotland.