Happily, the above quote from Richard Fitter's famous book London's Birds is no longer true. The peregrine falcon (Falco peregrinus) with its steel-grey back and barred underparts is indeed a magnificent bird, renowned as perhaps the fastest animal in the world when stooping on its prey. It has captured the imagination of people throughout its world-wide range. To own a peregrine was a status symbol among British and European nobility in past times and it is a highly sought-after species among falconers today.

The peregrine falcon is currently colonising London as part of a national recovery from serious declines in the middle of the 20^th century. Poisoning from organochlorine pesticides such as DDT was the primary cause of these declines, but there are now around 2000 pairs in the UK · probably an all-time high.

Largely a cliff-nesting species throughout its world range, peregrines readily take to nesting on large buildings in urban areas, notably in New York but also in many other North American and European cities. In the UK, peregrines nest on bridges, gasometers, pylons and buildings, including a nest box on a tower block in Brighton.

In London, the peregrine has always been a scarce passage migrant and winter visitor, with records increasing in recent years. The inner Thames marshes are an important feeding area for visiting peregrines in winter. Peregrines have been recorded mainly in the following boroughs: Wandsworth, Southwark, Havering, Newham, City of London, Sutton, Richmond, Westminster, Kensington & Chelsea, Islington and Camden.

Although there are unconfirmed reports of nesting on St Paul's cathedral in the 1860s, the pair that fledged two young on the derelict Spillers Millennium Mills building in the Royal Docks in 1998 are probably the first to breed in London. This site has not been used for nesting since, although peregrines occasionally roost there. In recent years single birds and pairs have frequented Beddington Farmlands (Sutton); the Wetland Centre, Barnes; Bankside Power Station (now Tate Modern) and the nearby Kings Reach Tower, though no nesting has been recorded. However, Battersea Power Station was home to a successful pair in 2000, with at least one young fledged. Just outside Greater London, a pair has nested for the last four years on Littlebrook Power Station, Dartford. They were successful for the first time in 2000, fledging two young.

Peregrines do not build a nest, but make a shallow scrape if there is soft substrate available. Although there are plenty of suitable buildings for peregrines in Thames-side locations throughout London, soft substrate is usually lacking. This could lead to eggs rolling off ledges or being otherwise damaged. The provision of nest boxes or trays containing a layer of soft substrate can help solve this problem.

Young peregrines taking their first flight can usually scramble back up a natural cliff to return to their nest, or at least to a place of safety. The smooth vertical face of a building allows no such opportunity and may result in half-fledged young birds becoming stranded in the street. Careful design and positioning of nest boxes may reduce the incidence of this.

Illegal persecution may be a significant factor slowing the increase in peregrine populations whether for egg collecting or falconry, or to prevent perceived losses of game birds or racing pigeons. Although such persecution is less likely in urban areas, security is an important consideration where selecting a location for a nest box.

Food is plentiful in London, where feral pigeons are abundant year-round and teal and black-headed gulls common in winter.

In the UK the peregrine is afforded full protection as a Schedule 1 breeding species under the Wildlife and Countryside Act (1981, as amended). It is also listed on Appendix II of the Berne Convention on the Conservation of European Wildlife and Natural Habitats, 1979; Appendix II of the Bonn Convention on the Conservation of Migratory Species of Wild Animals, 1979; and as a species requiring special conservation measures on Annex I of the European Union Directive on the Conservation of Wild Birds, 1979.

The British Trust for Ornithology is undertaking a national survey of the species (2001).

Nest boxes have been provided on buildings frequented by peregrines in several places in the UK, including Littlebrook Power Station, just outside London.

The Hawk and Owl Trust are undertaking research on the foraging ecology of peregrines by analysis of prey remains from around nest sites and feeding posts.