ADVICE FOR HOUSEHOLDERS ON ROOF NESTING ‘SEAGULLS’
There are several species of gulls which can be seen locally and to many people they are all just "seagulls", the Lesser Black-backed and Herring Gulls commonly nest on buildings.
Roof nesting by gulls is a fairly recent phenomenon. It should however be noted that occasionally other birds that might be mistaken for Lesser Black-backed and Herring Gulls.
These other "roof nesters" are discussed in the section The Law
Many people who have gulls on their property find they cause a nuisance. Commonly cited problems
Noise, caused by calling gulls and by their heavy footsteps.
Mess caused by their droppings, fouling of washing, gardens and people.
Damage to Property
The birds can dive and swoop on people and pets. This usually occurs when chicks have fallen from the nest and adult birds attempt to prevent them coming to harm by frightening away potential threats.
Blockage of gas flues by nesting materials can have serious consequences if gas fumes are
prevented from venting properly.
Lesser Black-backed Gull Herring Gull
The identification of these two large, white-headed species is straight-forward in adult plumages. They all show white heads, underparts and tails and have yellow bills, however:
Herring Gulls show a silver-grey mantle and pink legs. Lesser Black-backed Gulls show a slate-grey mantle and yellow legs.
The species-split in Cardiff is thought to be over 5:1 in favour of Lesser Black-backed Gulls.
Gulls are large birds. They are, in fact, about 55 cm (22") from bill to tail with a wingspan of about 85
Breeding pairs court in March and commence nest building from early April onwards. In towns, the
nest is constructed from straw and grass, twigs, paper and any other material the gull can
conveniently use. The nest can be quite large and, if made of material accumulated over several
years, very heavy.
Eggs are laid from April to May onwards with two or three being the usual number. The eggs take
about three to four weeks to hatch so the first chicks are generally seen about the beginning of June.
The chicks grow quickly and are quite active and often fall from the nest. In towns this almost
certainly means they cannot return to the nest. Small chicks will die unless returned but larger chicks
will be protected and fed by their parents on the ground. Parent birds protecting fallen chicks are the
ones which dive and swoop on people and animals, who often do not know the chick is down on the
Chicks generally fledge in August and then take three or four years to reach maturity and breed. The
life expectancy of a Gull which reaches maturity is about 20 years.
Gulls will tend to return to the same nesting site and unless action is taken to proof a building,
problems associated with these birds may recur annually.
The principal legislation dealing with the control of birds is the Wildlife and Countryside Act 1981. The
purpose of this section is to provide information on the legal background, as it stands at present.
This is a BRIEF GUIDE only and not meant to be an authoritative source of information.
Generally, it is illegal to capture, injure or destroy any wild bird or interfere with its nest or eggs. The
penalties for disregarding the law can be severe.
However, General Licences issued by the National Assembly for Wales (NAfW) allow measures to be
taken against certain common species of birds on grounds which include the preservation of public
health or public safety. Any action taken must be humane and the use of an inhumane method which
could cause suffering would be illegal. The use of poisons or drugs to take or kill any bird is
specifically prohibited except under very special circumstances and with a specific licence issued by
The list of birds against which humane methods may be used includes Lesser Black-backed and
Herring Gulls. However, only the owner of a building or the occupier can take action against the Gulls
on it, or they can give someone else permission to act on their behalf.
In practice there are very few humane methods to kill birds which are likely only to affect a particular
species, and skill and experience is needed to deploy them.
Falconry services would discourage people from themselves attempting to kill Herring gulls which nest on their property.
Know Your Gulls
Whilst the gulls which nest on buildings are usually Lesser Black-backed and Herring Gulls, there are
several other gull species which occasionally nest on buildings. The following species are examples:
Much smaller than Herring gulls and more delicate, they usually nest on steep cliffs.
Occasionally, however, they nest in colonies on building ledges.
Slightly smaller than a Herring gull, wings look very stiff and straight in flight. Nest occasionally on fronts of large buildings overlooking the sea. Although Fulmars look like gulls they in fact belong to a different bird family. Kittiwakes and Fulmars are fully protected under the law. Anyone interfering with them, their nests or eggs could be committing a criminal offence.
If you have any doubts about what kind of "gull" is nesting on your property, please ask someone
who knows. Our own staff are able to offer assistance if required.
What Can I Do?
The best time to undertake any deterrent work is outside of the nesting season. (see life cycle
All owners/occupiers of buildings which have, or may attract, roof nesting Gulls are strongly urged to
provide the building with deterrent measures suitable to the individual building. The principal methods
of deterrence are:
Fitting of long spikes to nesting locations such as chimney stacks.
Fitting of short spikes, contained in a special plastic base, to nesting locations such as
Fitting of wires or nets to prevent Gulls landing.
Because of the problems of fixing and the danger of trapping birds in or under nets, consideration of these methods should always be done by, or after having taken advice, from a competent specialist.
Disturbance of Nesting Sites – including removal of eggs can be a useful way of deterring gulls from nesting.
Where access to flat rooves are easily and safely obtained, it is worth checking these from mid-March onwards. Any nesting materials gathered by Gulls can be cleared away regularly. It is worth rechecking the nesting site weekly until the middle of June to make sure that if birds return the site is again cleared.
If access to rooves are difficult, you may wish to ask Falconry services and may also offer advice on proofing at the same time as the nests and eggs are cleared.