Urban gulls and their management in Scotland: review

1 Introduction and background to the project

1.1 The need for the project

The presence of large colonies of urban gulls within towns and cities throughout the UK is increasingly being flagged as a problem for residents, tourism and businesses, and is reported as stretching the resources of several Local Authorities. The most commonly reported problems caused by gulls in urban areas relate to removal of litter from bags and bins, fouling with droppings, the noise resulting from gull activities, and aggressive behaviour towards people during the breeding season, when gulls behave in a territorial manner. These problems were highlighted recently at the UK's first conference on urban gulls organised by Gloucestershire City Council (see http://www.glos-city.gov.uk/libraries/templates/page.asp?URN=2162). In Scotland, there has been a recent upsurge in complaints from the public and Local Authority staff about the problems caused by gulls in urban areas (Scottish Executive pers. comm.). The appearance, and increase in numbers, of roof-nesting gulls has been noted elsewhere in Europe, with Herring Gulls first observed nesting on roofs in Belgium, for example, in the early 1990s (J. Seys pers. comm.). There has been interest in starting a project on problems perceived to be associated with urban gulls in Belgium and a summary proposal for this is available on the European Community Initiative INTERREG III B website

( http://www.nweurope.org/page/projetIdea.php?p=22&id=4). To date, however, no research in Belgium has being carried specifically on urban gull problems, and despite extensive searches, neither we, nor our Scottish Executive contacts, could find any reference to other such projects in mainland Europe.

The issue of urban gulls is a complicated one to address for a number of reasons. Of the five species of gull occurring in urban areas in Scotland, four species (Black-headed, Common, Herring and Lesser Black-backed) are listed currently (on the Amber List, 'medium concern') as Birds of Conservation Concern (Gregory et al. 2000, see Chapter 4). The results from the latest full census of breeding seabird numbers in Britain and Ireland ('SEABIRD 2000') provide further evidence of declines in Herring Gull numbers at coastal locations that qualify the species for the UK Red List (Mitchell 2004). In contrast, pronounced increases in numbers of breeding gulls have been observed at existing and new urban colonies (Raven & Coulson 1997, Mitchell et al. 2004). The reasons for the divergent population trends between urban areas and the wider countryside are not established scientifically (e.g. Mitchell et al. 2004) but the plentiful food supplies provided by street litter and landfill sites, and the safe nesting and roosting areas available have been suggested as making urban areas attractive to gulls.

Many Local Authorities in Scotland have the powers, expertise and knowledge to deal with gull problems and some have already developed best practice guidance to deal with particular issues. All wild birds in Scotland are protected under the Wildlife and Countryside Act 1981 ( WCA 1981) but derogations can be granted under Section 16 of the Act to take action for certain stated purposes that would otherwise be illegal. The Scottish Executive issues General Licences annually under Section 16 of the WCA 1981 and sends these to all Scottish Local Authorities, enabling them to take action (including the taking of nests and eggs, and the taking and killing of fully grown birds) against Herring, Lesser Black-backed and Great Black-backed Gulls) for certain stated purposes. For other gull species, and certain types of control activities (see Chapter 7), individual specific licences can be sought from the Scottish Executive. Evidence to date suggests that there is no common approach to the control of urban gulls across Scotland, however, and that Local Authorities differ in their interpretation of the available legislation and powers contained within the General Licences. Neither are there common guidelines available on the range of control methods available for use and the scientific evidence for their effectiveness.

The issue of urban gulls has been raised a number of times in the Scottish Parliament in recent years. A Members' debate was held in Parliament on 7 November 2002 to discuss the issue. At the end of this debate, Allan Wilson, the Deputy Minister for Environment and Rural Development gave an undertaking to look at the problem, with a view to potentially producing best practice guidance for Scottish Local Authorities on the management of urban gulls. This report contains the findings of the study commissioned by the Scottish Executive as a result of the Scottish Parliament Members' debate.

1.2 Aims of the project

The research aim of this project was to review the problems caused by urban gulls and to, as far as scientifically possible, propose best practice guidance to manage the problem. Specifically, the study aimed:

• To produce a comprehensive scientific review of current knowledge of the ecology of urban gulls, why they are attracted to Scottish towns and the relevant key issues and research areas;
• To identify locations throughout Scotland where urban gulls are or are not perceived as a problem (including the extent of current information on local population sizes and trends and its scientific rigor);
• To review current Legislation and powers, how these are used currently throughout Scotland, and their perceived effectiveness;
• To identify management practices in operation currently in Scotland and elsewhere, review scientific evidence for their success or failure, and contrast their strengths and weaknesses in specific contexts; and
• To propose possible solutions (advise on standard best practice guidance) and highlight areas where further research is likely to be required.

1.3 Expertise of contractors

1.3.1 BTO Scotland

The British Trust for Ornithology ( BTO) has existed since 1933 as an independent, non profit-making, scientific research trust, investigating the populations, movements and ecology of wild birds in Britain. The organisation prides itself on carrying out high-quality and impartial research on birds. BTO is not a campaigning organisation or pressure group, which means that the data gathered and all results published, are objective and unbiased. The BTO Scotland office at the University of Stirling employs a small team of dedicated staff with the remit of undertaking high-quality, impartial research of particular relevance to the Scottish context. The BTO has been at the forefront of developing survey techniques for birds in Britain and has run, or runs currently, UK-wide surveys or annual monitoring of a range of species, as well as multi-species surveys ( e.g. the Breeding Bird Survey ( BBS), Wetland Breeding Bird Survey ( WBBS), Wetland Bird Survey ( WeBS); see www.bto.org ). This means that the BTO has first-hand expert knowledge of the caveats associated with deriving population estimates from survey data and experience of appraising the quality of such estimates that is second to none. BTO Scotland has staff members with particular expertise on seabirds and gulls (John Calladine and Chris Wernham carried out a previous more general review of gull impacts and control techniques for Scottish Natural Heritage, Calladine & Wernham 1996). The BTO is running a UK-wide survey of wintering gulls in the winters of 2003/04-2005/06, and John Calladine is the Scottish contact point for this survey. Dr Nigel Clark, Head of Projects at the BTO in Thetford, regularly advises designers on ways to mitigate the problems caused by roof nesting Gulls on new large developments.

1.3.2 Centre for Conservation Science

The Centre for Conservation Science, a joint initiative by the Universities of St. Andrews and Stirling, was established in 2001with funding from the Scottish Higher Education Funding Council. The overall objective of CCS is in the use of advanced analysis techniques to inform on controversies and uncertainties associated with conservation issues, with a particular focus on Scotland. CCS has been involved with a range of programmes related to Scottish conservation management issues, including the ecology and management of invasive species (North American Mink, European Hedgehogs, Sika Deer and Rhododendron ponticum), and the impact and management of generalist predators (in particular raptors and gamebirds, Grey Seals and marine and freshwater fisheries). Much of this work involves multi-organisation collaboration, reviewing scientific evidence, evaluating the effects of different management strategies, conflict resolution and stakeholder consultation.

1.3.3 Dr Kate Thompson

Kate Thompson is an independent ecological consultant, who was previously employed as Seabird Monitoring Programme coordinator by JNCC and has first-hand experience of evaluating the quality of gull population data and of dealing with requests for information to assist with conflict situations.