Seagull Guide: Behaviour, Breeding & Identification

Gulls are a familiar sight across the UK, particularly in coastal towns and increasingly in urban areas. Rooftops provide sheltered nesting locations, while access to food and suitable breeding sites can encourage gulls to return year after year. Understanding their behaviour and breeding cycle is an important first step in managing gull-related problems.

Herring Gull Vital Statistics

Eggs	2–4
Incubation	28–30 days
Fledging	35–40 days
Maximum lifespan	31 years
Length	53–59cm
Wingspan	125–155cm
Weight	690–1,495g

Seagull Breeding and Behaviour

Adult gulls typically form long-term breeding pairs and often return to the same nesting locations each year. Herring gulls generally reach breeding maturity at around three to four years old, and established nesting sites may be used repeatedly over many breeding seasons.

Eggs are commonly laid during April and May, with chicks hatching from late May into June. Gulls can become particularly protective of their nests and young during the summer months, with defensive behaviour often most noticeable in June, July and August.

Noise can become a problem from early spring as gulls return to breeding sites. Their calls may continue throughout the day and night, particularly in areas with established rooftop colonies. Gulls may also swoop towards people or pets when defending nearby chicks.

Gulls are opportunistic feeders and readily take advantage of accessible food waste. Open bins, discarded food and intentional feeding can encourage gulls to gather around buildings and public spaces. Keeping waste secure and avoiding feeding gulls can help reduce these attractants.

Property Damage Caused by Seagulls

Gulls can cause damage to buildings by pulling at roofing materials and using them to construct nests. Nesting materials can block gutters and drainage systems, leading to water build-up, damp and potential damage to the roof structure.

Gulls often choose rooftops, chimneys and areas around ventilation systems as nesting locations. Large nests can obstruct vents and flues, potentially creating serious safety risks where ventilation for gas appliances is affected. Regular inspections can help identify nesting activity and potential problems before damage occurs.

Seagulls and UK Wildlife Law

All wild birds, including gulls, are protected under the Wildlife and Countryside Act 1981 in Great Britain, with separate legislation applying in Northern Ireland. It is generally an offence to intentionally kill or injure wild birds or damage or destroy their active nests or eggs without appropriate legal authorisation.

Certain gull management activities may be permitted under specific licences, subject to the species, circumstances and relevant licensing conditions. Property owners and pest control professionals should check the latest guidance from the appropriate wildlife authority before carrying out any work that could affect gulls or their nests.

Preventative bird proofing, such as correctly installed netting and other suitable deterrents, can help discourage gulls from nesting on buildings. Where active nests are present, professional advice should be sought before proceeding.

Seagull Droppings and Disease Risks

Gulls frequently feed around waste disposal areas, landfill sites and other locations where food is readily available. Their droppings can contain harmful microorganisms, including certain strains of E. coli and Salmonella, which may present hygiene risks where contamination occurs.

Accumulated gull droppings can also create unpleasant conditions around entrances, walkways, rooftops and outdoor seating areas. Regular cleaning, appropriate hygiene precautions and effective bird management can help reduce contamination and maintain cleaner environments.

How to Prevent Seagulls Nesting on Roofs

Preventing gulls from nesting on buildings is often more effective than dealing with established nesting activity. Installing suitable bird proofing before the breeding season can help protect rooftops, reduce property damage and discourage gulls from returning to problem areas.

Bird Netting

Bird netting creates a physical barrier that prevents gulls from accessing protected areas. 75mm gull netting is commonly used to protect rooftops, courtyards and other open spaces where gulls may attempt to nest.

Bird Spikes

Seagull spikes can discourage gulls from landing on ledges, parapets and roof features. Choosing the correct spike width and configuration is important for effective protection, particularly in areas regularly used by larger birds.

Other Gull Deterrents

Visual and specialist bird deterrents may help discourage gull activity in certain locations. The effectiveness of these solutions depends on the environment, level of bird pressure and correct installation.

Remove Food Sources and Maintain Roofs

Keeping food waste secure, clearing debris and maintaining gutters can help make buildings less attractive to gulls. Regular roof inspections can also identify potential nesting areas before birds become established.

Before installing bird proofing, always check for active nests and ensure any work complies with relevant UK wildlife legislation. Professional advice is recommended for complex rooftop installations.