Use of falcons to displace nesting gulls from an urban area: final report

1. Introduction

The number of gulls, especially Lesser Black-backed ( Larus fuscus) and Herring Gulls ( Larus argentatus), nesting in towns and cities in the UK has increased steadily (Mitchell et al., 2004). Away from traditional rooftop nesting sites in coastal towns, gulls now breed in significant numbers in the majority of the major built up areas in Scotland, England and Wales (Calladine et al., 2006), (Burton et al., 2004). These species are often cited as causing problems in terms of noise nuisance to residents, blockage of drains, ventilation and gas outlets, transfer of disease organisms or ectoparasites to dwellings, aggression towards the public near nests and fouling of buildings and pavements (Butterfield et al., 1983; Baxter & Robinson, 2007). The growth in urban nesting by gulls shows no sign of slowing at the moment hence reliable, scientifically proven techniques for management of these issues are required.

Falcons and hawks have been used for many years to deter gulls from a variety of industrial and domestic landscapes (Baxter & Allan, 2006). Deployments have ranged, for example, from occasional flying of single falcons within small domestic estates, through regular flights of several (consecutively flown) hawks or falcons across industrial complexes to long-standing daily flights at landfill sites or on airport facilities (Cain, pers comm.). Their effect has, however, rarely been documented with the scientific approach required to fully evaluate their use. Little is also known about the wider impacts of the use of falconry and how it impacts on the movements and behaviour of targeted birds. Where scientific studies have been completed, hybrids of Peregrine falcons ( Falco peregrinus) have the potential to be used successfully against gulls (Baxter & Allan 2006). These studies have shown that falcon hybrids ( Falco sp.) were more effective than hawk species ( Buteo and Parabuteo sp.) at deterring gulls in a waste management situation but that effective control required a permanent dawn to dusk presence. They have also suggested that the driver behind the success of falcon hybrids, as opposed to hawk species, is their ability to capture target birds. The benefits of having a regime in which such a 'lethal threat' is exhibited have also been recorded in other studies (Dolbeer, 1998; Meltofte et al., 1996). The opportunity to scientifically monitor gull deterrence using Peregrine Falcons and associated hybrids of Peregrine Falcons, within Dumfries town centre, was therefore presented by Dumfries and Galloway Council, the Scottish Government and Scottish Natural Heritage ( SNH). This report summarises the findings from these studies.