Herring gulls are a common sight in coastal towns across the UK. With their distinctive loud calls and opportunistic feeding habits, these large gulls have become a nuisance for many communities. But what exactly is the problem with herring gulls, and why have they become so problematic in recent years?
Quick overview – What are herring gulls?
Herring gulls are medium to large-sized gulls with pale grey backs and wings, black wingtips, and white underparts. Their scientific name is Larus argentatus. They are a migratory species, breeding in the northern hemisphere during spring and summer before migrating south for the winter. Herring gulls have a widespread distribution, found across coastal regions of the North Atlantic, North Pacific, and North Sea.
Originally, herring gulls nested on cliff sides and remote islands away from human activity. But in the past few decades, they have adapted to live in urban environments and now commonly nest on rooftops in towns and cities.
Why are herring gulls a problem?
There are several reasons why herring gulls have become problematic in urban areas:
- Aggressive scavenging behavior – Herring gulls have lost much of their natural wariness towards humans and scavenge for food scraps wherever they can. This can lead to aggressive swooping if they think food is present.
- Noise pollution – Their loud, shrieking calls are a nuisance early in the morning and late at night when breeding pairs become territorial.
- Fouling – Gulls frequently drop messy feces on buildings, cars, and public spaces, causing hygiene issues.
- Interference with waste management – Scavenging gulls tear open rubbish bags left out for collection and spread litter while searching for food.
- Predation – Gulls may predate the chicks and eggs of other cliff-nesting seabirds. Their numbers have contributed to declines in species like kittiwakes.
This combination of factors means herring gulls can seriously degrade the quality of life for people in coastal towns where gull populations are high.
Urban nesting behavior
The main driver behind the problematic rise in herring gull numbers is their behavioral shift towards nesting in urban areas. Traditional coastal cliff sites provide fewer safe nesting spots due to erosion and human disturbance. But herring gulls have realized that urban rooftops provide ideal nesting habitat:
- Flat, gravel-covered rooftops resemble natural cliff nesting sites.
- Urban areas provide abundant food from human waste.
- Nest sites are safer from most predators.
- Gulls have protection under the Wildlife and Countryside Act 1981, so cannot be removed or disturbed once nesting.
For these reasons, urban rooftop colonies provide ideal conditions for gulls to successfully hatch chicks each breeding season. With ample food availability, reproductive rates are high. This has caused populations of urban nesting gulls to rise substantially.
Extent of population growth
According to the JNCC, herring gulls have shown a 129% increase in their UK breeding population over 25 years between 1969-1994. More recently, the Seabird Monitoring Programme estimates there are approximately 148,000 breeding pairs across Britain.
Herring gulls expanded rapidly into urban areas from the 1980s onwards. One study found numbers of roof-nesting gulls increased seven-fold between 1975 to 2000 in Bristol. Some individual cities now have 10,000 pairs or more, including around 20,000 pairs in Aberdeen.
Conservation measures that protect nest sites have enabled the overall population to grow. And ample access to human food waste supports higher reproductive rates in urban colonies.
Impacts on people
For many people living and working in towns with major herring gull colonies, the birds’ behaviors have serious impacts on daily life:
- Noise – Early morning shrieking, squabbling, and chick begging calls disturb sleep and create excessive noise pollution.
- Mess – Feces staining on buildings, cars, and footpaths creates unhygienic conditions and costs money to clean.
- Litter – Torn open rubbish bags and scattered waste from scavenging gulls makes streets messy and unattractive.
- Aggression – Swooping, diving attacks and food snatching are common during the breeding season as gulls protect nest sites.
- Predation – Pets and smaller wildlife may be at risk of predation by gulls. There are cases of dogs and cats being snatched.
This can degrade the visual appearance of urban environments, while excessive noise and mess create stressful living conditions for residents. There are also economic impacts through clean-up costs for councils and damage to buildings from fouling.
Health risks
The behaviors of herring gulls in urban areas also pose some health and safety risks:
- Fecal contamination – Gull droppings contain bacteria such as E. coli and Salmonella that can cause illness in humans through contact or transmission via food and water supplies.
- Airplane strike risk – Birds getting sucked into aircraft engines during take-off and landing poses a safety risk at airports near gull colonies.
- Injuries from swooping – Aggressive swooping and diving during the breeding season has led to injuries such as cuts from gull pecks.
Proper hygiene practices can reduce the disease risks from gull fecal contamination. But airplane strikes and swooping injuries remain an inherent problem from urban gull populations.
Economic impacts
Besides degrading the urban environment, herring gull overpopulation also creates direct economic costs for local municipalities and businesses:
- Cleaning costs for removing fecal mess from pavements and buildings.
- Waste management programs must contend with torn open rubbish bags and scattered litter.
- Property maintenance and repair costs from nesting damage and fouling on rooftops.
- Reduced tourism revenue due to unpleasant urban environment saturated by gulls.
One study estimated total economic costs of £2-3 million per year for a small UK town hosting a large herring gull colony. This suggests the national economic burden across all affected towns is substantial.
Risks to aircraft safety
The presence of gull colonies near airports poses a risk to aircraft safety. Bird strikes where birds are sucked into jet engines or smash into planes can cause serious accidents.
Analysis shows gulls accounted for 15% of all bird strikes reported in the UK between 1990 – 2004. And aircraft collisions with gulls are more likely to cause damage compared to smaller bird species due to their larger size.
Major airports such as Heathrow, Gatwick, and Edinburgh all lie close to large gull colonies. This requires active management such as habitat modification, bird scaring techniques, and egg oiling schemes to reduce the local gull population and minimize strike risks.
Notable airplane accidents caused by gulls
- US Airways Flight 1549 ditched into the Hudson River after multiple Canada goose strikes took out both engines in 2009.
- Ryanair Flight 4102 crash landed after herring gull strikes in Rome in 2008.
- Ethiopian Airlines Flight 604 crashed after a flock of gulls were ingested into the engines after take-off from Bahir Dar in 2010.
These severe accidents demonstrate the serious safety risk urban gull populations can pose to aviation. Ongoing monitoring and control of gulls near airports is crucial.
Declines in other seabird populations
Some conservationists are also concerned that growing herring gull numbers may contribute to declines in populations of other threatened seabird species. This includes:
- Kittiwakes – Red-listed in the UK due to an 83% population decline since 1986. Nesting kittiwakes can be outcompeted and predated by herring gulls.
- Terns – Breeding terns such as Sandwich terns are vulnerable to nest predation and displacement from habitat by herring gulls.
- Puffins – Herring gulls will take puffin eggs and chicks. Puffin colonies have declined following herring gull invasion at some sites.
Limiting herring gull overpopulation may therefore be necessary to protect rarer seabirds that play an important role in the overall ecosystem.
Control and deterrent measures
A variety of control measures have been attempted to limit herring gull nuisance problems and reduce numbers in urban colonies:
Deterrent Methods
- Scarecrows – Human or bird of prey effigies can deter gulls from nesting on rooftops.
- Wire grid systems – Plastic spikes or taught parallel wires can prevent gulls landing on ledges and roof spaces.
- Reflective tape – Silvered tape gives the impression of open space that gulls avoid.
- Sonic bird scarers – Devices emitting predator calls, gull alarm calls, or loud explosive sounds can scare birds away from an area.
- Falconry – Trained falcons flown by handlers can scare and chase away problem gulls.
Population Control Measures
- Egg oiling – Coating eggs in liquid paraffin oil prevents them hatching and reduces breeding success.
- Nest and egg removal – Destruction of active nests. Removal must take place outside the breeding season to avoid breaking the law.
- Culling adults – Shooting or euthanizing adult gulls has been used at some sites but is controversial.
A integrated management plan using a combination of deterrent and population control measures tailored to the local situation is recommended. This requires commitment and funding from local authorities over the long-term.
Public education
For management efforts to be successful, public education is also vital. People must cooperate and stop feeding gulls, or sabotaging control measures due to sympathy for the birds. Outreach should emphasize:
- Why reducing gull overpopulation is important.
- Health risks from gull fecal contamination.
- How feeding gulls sustains overpopulation.
- Discouraging gull nesting or chick rescue.
- Proper household waste containment and disposal.
With greater public understanding, nuisance gull issues can be tackled more effectively.
Outlook for the future
If current trends continue without action, herring gull overpopulation problems seem likely to get worse in urban areas. Some experts predict a ” Lost Generation” scenario, where people no longer recall a time without overwhelming gull nuisance issues.
This underscores the need for a comprehensive national strategy for sustainable gull population management. With coordinated efforts between local authorities, wildlife agencies, airports, and public cooperation, it should be possible to contain issues. Herring gulls may always remain a feature of coastal towns, but their numbers and impacts can be reduced to tolerable levels with persistent management.
Conclusion
In summary, the key problems caused by urban overpopulation of herring gulls include:
- Noise, mess, litter, and aggression towards people
- Health and safety risks from fecal contamination and airplane strikes
- Major economic costs for municipalities and businesses
- Predation and displacement impacts on other rarer seabird species
Control measures such as deterrents, egg oiling, and public education campaigns can be effective as part of an integrated management strategy. With commitment from authorities and public cooperation, herring gull populations may be controlled at more sustainable levels in future.