Seagulls? Your most expensive choice is to do nothing……

Gulls (Laridae) are medium to large-sized, long winged, conspicuous birds that often occur in large flocks or colonies. Gulls nesting on buildings, mainly in coastal but often now in towns inland, has increased markedly in recent years. Nest sites include private houses, hotels, large warehouses and factories. They will fly great distances for food, often at landfill sites especially during the winter, sewage outlets or agricultural land. Other food sources include scavenging from urban and commercial food waste. Once a breeding site is established the gulls will return to it year after year. They don’t go away, you know!

There are six species: herring gull, lesser black-backed gull, great black-backed gull, black headed-gulls, common gull and Kittiwakes. They start breeding when five years old and can live for up to 25 years. Eggs are laid in April or May with up to three eggs being laid at two to three-day intervals. Incubation takes 28-30 days. The young can make their first flight at about 10 days old but do not leave the nest area until after five to six weeks’, so the breeding season extends to August. A single brood is the norm, per season but if eggs are removed or destroyed they can relay several times a year in a season.


If you have had them before, then act rather than ignore it as they return to the same location every year. Seagulls that hatch on a roof will return at three years old and nest in the same spot they were born. Allowing them to establish a nesting colony on a building is bad practice. Ignoring one, followed by another can lead to exponential population growth and big repair costs. Nesting birds are noisy, aggressive and cover the surrounding area with their guano, which corrodes paint and etches into cladding coatings. Nest debris blocks roof drainage systems causing flooding risks. Gulls are inquisitive by nature and will pick at wiring, insulation and roof coverings causing further building degradation. Seagull guano presents a health and safety hazard, with slips, trips and falls. Their guano carries many transferable diseases to humans. Gulls are most aggressive when they have young in the nest. Employers and landlords have a duty of care to staff, tenants and third-party visitors to provide a safe working environment.


There are a variety of proofing systems against gulls e.g. netting, parallel wires, spikes, sprung wire systems, daddi long legs and specialist anti-bird chimney cowls are available from Ecologica from €40. Gulls are very heavy birds so appropriate heavy-duty equipment and techniques are required. Any proofing on nesting areas needs to make sure that birds cannot land nearby and drop nesting materials onto a nest site and build up a nest through the proofing. Roof nets are increasingly being used to protect large roof areas from nesting and loafing gulls.


Use of bio-acoustic call systems to disperse gulls from large areas such as marinas and factory roofs have been found to have some effect. The award-winning autonomic laser bird dispersal systems which are ideal solution for many commercial premises as they are silent and produce immediate results. Predator birds as part of a deterrence programme are very effective e.g. harris hawk–are used at live sporting events for keeping gulls away are effective and an environmentally friendly solution.


If you are losing business revenue, resources or people due to a seagull infestation, be pro-active, save your business goodwill and call Ecologica for a site survey and environmental risk assessment.


Mervyn Walsh, Field Conservation Biologist

Ecologica Environmental