- "WATERFOWL" INFORMATION
NETWORK International Conference
Click here for CONTENTS Page
The Management of Problems caused by
Canada Geese - A Guide to Best Practice
Author: Dr John Allan, Central
The production of this paper was funded
by the Department of Environment Transport and the Regions. It forms the basis of national
guidelines for the management of Canada Geese which are due to be published shortly after
this conference. I am most grateful to the DETR for permission to reproduce this paper in
the conference proceedings.
The Canada Goose population in Britain numbers over 63,000 birds and is
still increasing. The geese live in local populations, usually of up to a few hundred
birds, which remain around one or two water bodies that offer suitable habitats for
breeding, roosting etc. Because the geese have relatively few predators, and can produce
four or five young per year, numbers at particular sites can grow very rapidly and
significant problems may occur.
Any management techniques used to control the problems caused by Canada
Geese must be legal (Canada Geese are protected under both British and European
legislation) and should take account of the fact that Canada Geese are a popular species
with many members of the general public.
This paper aims to provide land managers with the information that they
need to manage difficulties caused by Canada Geese in a way that is effective, legal and
sensitive to public opinion.
The Biology and Behaviour of Canada Geese
In order to develop an effective management strategy for any nuisance
wildlife, it is necessary to understand enough about the biology of the species and the
local population involved to be able to predict the outcome of whichever management
techniques are chosen. This section gives a brief point by point overview of the biology
of Canada Geese in Britain insofar as it affects the management of the species.
A single clutch of around 6 eggs is laid in early April each year.
Incubation, solely by the female, takes 28-30 days.
Nests are usually close to water bodies, often on islands which provide
some protection from predators such as foxes, dogs or mink.
The adult geese defend a small territory around the nest, but are
willing to tolerate other pairs nesting nearby, so large colonies can build up on sites
with enough nesting territories and adequate food supplies.
The geese are aggressive in defence of their nests and will attack
Canada Geese, other waterfowl, and even humans who approach too closely.
1.2 Fledging and the moult
The hatched young are flightless for 10 weeks and are protected by
the adults on the water at the breeding site.
Mortality rates are highest for very young fledglings, but become
little different from adults once the young are more than a few weeks old.
The adult birds moult around the end of June and are unable to fly for
a 3-4 week period.
During the moult, both adult and juvenile birds must feed from the
water or walk to find food.
The amount of suitable food available at a site during this period may
be important in governing the number of breeding pairs that it can support.
Some birds, which have either not attempted to breed or which have
failed to raise a brood, undertake longer journeys to find the best sites to moult. Some
birds from Yorkshire and the West Midlands fly as far as Scotland to find suitable
The geese normally remain close to the site where they hatched, and
once young birds mature they may wait several years for a breeding territory to become
Large flocks of non breeding adults may thus build up at certain sites.
Most Canada Geese remain faithful to their home area for life, even if
apparently suitable water bodies with no Canada Geese present are available nearby.
Females are generally more site faithful than males
Small numbers (usually of young birds) abandon their home area either
to join other groups or to establish new colonies.
Unlike their North American ancestors, Canada Geese in Britain are
mostly non-migratory, moving only short distances between breeding and wintering sites
within their local area.
Birds may fly out from the water bodies where they roost to regular
winter feeding sites such as waterside grazing pasture, amenity grassland etc. They may
also move around their home range taking advantage of feeding opportunities such as
sprouting winter cereals or root crops as they become available.
1.5 Causes of mortality
Adult Canada Geese have few natural predators in Britain, and most
of the known causes of recorded mortality are associated with man's activities. Annual
mortality is estimated at between 10 and 20% of the whole population. Juvenile birds have
the same level of mortality as adults once they reach their first moult.
The causes of death are:
- 67.2% shooting
- 4.3% hit power lines
- 5.5% redation
- 23% unknown.
There is little evidence that natural factors, which become more severe
as numbers of birds increase, such as limited food availability, act to control Canada
Low annual mortality and high reproductive rates give the national
population the scope to increase in size for the foreseeable future.
2. Problems Caused By Canada Geese
2.1 Grazing and trampling
Canada Geese are vegetarians, grazing on both land and water
Damage to amenity grassland in public parks, where the geese may occupy
regular feeding and roosting sites all year round can be severe.
Unsightly and un-hygenic areas of mud and droppings which are expensive
to reinstate frequently occur.
The geese may trample as well as graze pasture and crops.
2.2 Fouling with droppings
Because of the low nutrient value of their food, Canada Geese need
to eat large quantities of vegetation.
When feeding they may produce droppings at a rate of one every 6
The droppings contain bacteria that may be harmful if swallowed and
they also make grassed areas unattractive and paths slippery.
If the droppings are passed into water bodies they may cause increased
nutrient loadings leading to possible toxic algal blooms and low oxygen levels in the
2.3 Damage to wildlife habitat
Canada Geese can damage the habitat of other wildlife, for example
by grazing or trampling nesting sites of other bird species.
Destruction of waterside habitat, such as reed beds, by Canada Geese
can be a significant problem, leading to erosion of river banks in some cases.
2.4 Excluding other wildlife
There is little hard evidence that Canada Geese cause significant
problems by competing directly with other wildlife.
Aggressive confrontations do occur, and there is some evidence of other
large waterfowl being excluded by, or excluding, Canada Geese from a preferred breeding
Such interactions are rare, however, and are thought to have little
effect on the overall populations of other native waterfowl.
2.5 Birdstrike hazards to aircraft
The large size of Canada Geese makes a collision with an aircraft a
particularly hazardous event.
Recently, a United States Air Force AWACS aircraft (a large
four-engined jet) crashed following a collision with a flock of Canada Geese, killing all
The aviation industry continues to express concern about the increasing
numbers of Canada Geese on water bodies near aerodromes.
Planning applications involving the creation of water bodies suitable
for Canada Geese close to aerodromes may be refused on the grounds of flight safety.
3. Management Techniques
3.1 The protected status of Canada Geese.
The Canada Goose, like all other birds in Britain, is protected under
the EC Wild Birds Directive implemented in the United Kingdom through the Wildlife and
Countryside Act (1981). This makes it an offence to capture, kill or injure Canada Geese,
to damage their nests or eggs, or to disturb them on a breeding site. Any control
technique which involves breaking the protected status of the Geese requires a licence
from the appropriate government authority (see appendix 1).
Canada Geese can be legally shot by authorised persons or trapped by
approved methods in the open season (between September 1st and January 31st, or February
20th on the foreshore). The use of shooting or trapping by approved methods to control
Canada Geese during the open season does not, therefore, require a licence, but care
should be taken to ensure that other regulations concerning firearms safety, capture
methods etc. are adhered to. If in doubt, advice can be sought from the organisations
listed in appendix 1.
3.2 Integrated Management Strategies (IMS) For Canada Geese
Experience has shown that it is unlikely that a single management
technique will be fully effective in controlling a problem caused by Canada Geese. For
Fencing an area to keep birds off will simply cause them to move to
an alternative site close by and continue to cause damage.
Preventing reproduction by treating eggs to stop hatching will not
reduce the population of adults (and hence the levels of damage or nuisance) for many
Culling the adult population at a site may simply allow non breeding
adults from nearby waters to move in to vacated breeding territories.
In those cases where effective management of the problem has been
achieved, Integrated Management Strategies (IMS) which combine a suite of techniques have
invariably been employed. One of the most effective Canada Goose management programmes to
date involved the development of an IMS that combined reduction of adult numbers,
reproductive control and fencing to exclude birds in an IMS carried out by Wandsworth
Borough Council as part of a larger programme to improve the quality of its urban park
3.3 The Scale Of Management Required For A Successful IMS
Although the damage or nuisance caused by a group of Canada Geese may
be occurring at only one site, it is important to remember that the population of geese to
which the birds belong may be spread over a number of nearby waters. When developing an
IMS for a particular situation, it will often be necessary to manage birds away from the
site where the problem actually occurs. This is especially important if population
reduction is to be included in the IMS. For example, if scaring or habitat management
proved insufficient to control a problem at a wintering site, and population reduction by
egg control or culling became necessary, the breeding and moulting sites used by the
wintering birds would need to be identified and the co-operation of the landowners
obtained before this strategy could be implemented.
3.4 Available techniques for the control of problems caused by
The choice of which techniques to combine into an IMS will depend upon
the type of damage that is occurring, the type of control that is needed to reduce the
damage to acceptable levels, and the biology and distribution of the birds involved. A
series of examples are given at the end of this section.
The techniques available fall into two broad categories; the control of
behaviour, by scaring or excluding the birds from the site in question, and the control of
numbers, by manipulating the breeding rate or rate of mortality of adult birds. Some of
these techniques, especially those involving the manipulation of bird numbers, will
require a licence (see appendix 1). Where a licence is needed this is indicated below.
3.4.1 Behaviour modification (scaring, exclusion, repellent
Ground based scarers
Most visual scarers rely on the natural fear of the unfamiliar of
wild animals. Scarecrows of various designs, flags and flapping tapes have all been
employed to deter geese from areas such as sprouting crops. However, even migratory goose
species learn to ignore these deterrents and Canada Geese, which often live close to man,
are used to man made items. Scarecrows, whether human or animal effigies, windmills,
rotating mirrors etc., should be placed in the centre of the area where problems are
occurring and should be moved every 2 or 3 days to maximise their effect. Flags or flutter
tape should be attached to upright poles at regular intervals across the affected area. In
general, the closer the spacing of the flags the greater the deterrent effect is likely to
be. Visual scarers may be effective for short term deterrence of Canada Geese from
sensitive areas, especially if alternative sites are available nearby.
Kites and balloons
Other visual scaring techniques include kites and balloons, often
painted with large eyes or made in the shape of predatory birds. A threat from above may
be more intimidating for birds which may naturally be attacked by birds of prey, and a
single balloon may deter birds from a larger area than a ground based scarer. The devices
should be set to fly above the problem area during normal wind conditions. They may need
to be re-set if wind direction changes and may not fly well in heavy rain or very strong
winds. As with ground based scarers, birds will eventually learn to ignore them and they
are best used as short term deterrents when alternative sites are available for the birds
to move to.
Problems with visual scarers
Although effective in the short term, visual scarers have some
drawbacks, particularly in situations such as public parks. The scarers may be
unattractive and interfere with recreational use of areas and could be subject to theft.
They also require maintenance and some need to be moved on a regular basis to maximise
their effect. Visual scarers are particularly appropriate for use to protect agricultural
crops where the geese need to be excluded for a limited period of time such as during
sowing or prior to harvest.
Acoustic scarers, from the commonly used gas cannon through recorded
bird calls to complex solar powered artificial sound generators, are all marketed as being
effective in deterring Canada Geese. Most will deter the birds from relatively small areas
providing that there are alternative areas for them to use for roosting or feeding nearby.
Like visual scarers, the birds will eventually learn that they offer no threat, although
their effectiveness can be prolonged by moving the scarers every two or three days.
Acoustic scarers are often hidden (by deploying them at the edge of a field or behind hay
bales or other screens) so that the birds cannot see where the sound is coming from. This
is thought to prolong the time before the birds realise that the sound represents no
threat, but there is little scientific evidence to support this assertion.
Problems with acoustic scarers
As with visual scarers, acoustic scarers may be unsuitable for use in
areas frequented by the public due to the sudden loud noises involved, and the relatively
expensive equipment may be subject to theft or vandalism. These systems are more likely to
be of use to protect agricultural crops or to deter birds from islands or similar remote
c) Combined visual/acoustic
Some scaring systems combine visual and acoustic stimuli in order to
enhance the deterrent effect. Such systems vary from gas cannons which shoot a projectile
up a pole when the cannon goes off (in order to simulate a shot bird falling to the
ground) to an inflatable rubber man which emerges from a box accompanied by a loud klaxon.
The combination of visual and acoustic stimuli may lengthen the time before the birds
habituate to the scarers, and they will be more effective if moved every 2 or 3 days. All
of these systems have the same drawbacks as visual or acoustic scarers alone and are
suitable for use in similar situations.
d) Human operated bird control
For many bird species the most effective bird scarer is a human being,
armed either with a harmless scaring device such as a flag or firework, or with a shotgun.
Where Canada Geese are regularly shot, the simple presence of a human may be sufficient to
deter birds from an area. In most situations, however, Canada Geese show little fear of
man, particularly where they are used to being fed by the public. Even if the geese can be
trained to fear humans, the deterrent will only be effective if it is continuously
deployed whenever the geese are present. The resulting high cost of human operated scaring
of Canada Geese, by whatever method, means that it is usually only an effective option
when the damage caused is extremely expensive, or where the risks to health and safety are
extreme (e.g. in preventing birdstrikes to aircraft).
Shooting to support scaring
It is widely believed that periodic shooting of a small number of birds
helps to make them more wary and thus makes acoustic and visual scarers more effective.
Whilst there is little scientific evidence to support this theory, this may well be the
case, and licences to shoot limited numbers of birds to support scaring outside the open
season may be issued in certain circumstances.
Where scaring of Canada Geese is not desirable, it may be possible to
exclude the birds from sensitive areas by physically preventing them from gaining access.
As with scaring techniques, exclusion is likely to be most effective if alternative sites
are available for the birds to move to. These techniques may create some difficulties as
they affect other waterfowl species as well as Canada Geese. The erection of fences along
a lakeside may also have implications for public safety if someone were to fall into the
water and be unable to get out easily.
Perhaps the most obvious way to exclude Canada Geese is to fence
sensitive areas to prevent them gaining access. Despite the fact that the geese can fly,
even low fences of around 1m high can be effective in excluding them from some areas as
they prefer to walk to their feeding and roosting sites if possible, often landing and
taking off from water. Thus, fencing the edge of a lake may be sufficient to cause the
geese to move elsewhere if they are unable to walk easily out of the water. Canada Geese
dislike enclosed areas where they cannot easily escape from predators. Barriers that
divide fields into smaller units may therefore help to discourage the birds from using the
Fences have also been successfully used to exclude Canada Geese from
breeding and roosting sites, especially where alternative sites were available nearby.
Fencing the perimeter of park lakes is not necessarily an expensive option because a
simple post and chicken wire fence will suffice if properly erected, but a more decorative
and permanent structure may involve a significant cost. Fencing may be a particularly
effective option at sites used by moulting Canada Geese because if they are prevented from
walking out of the water whilst they cannot fly they will not be able to access the
feeding areas nearby. Care should be taken, however, to ensure that if moulting adults or
newly hatched young are found at a fenced site, they do not starve through lack of access
to grazing areas.
Barrier planting, marginal vegetation, trees
An alternative to fencing lake edges, or placing barrier fencing around
grazed areas, is to modify the vegetation in the areas suffering damage by Canada Geese.
Establishing areas of dense vegetation along the shores of water bodies (possibly
concealing a cheaper fence structure) or breaking up large grass areas with planting which
restricts the birds view of the water (and hence reduces its feeling of safety) have
all proved effective in certain circumstances. If Canada Geese do move out to feed in
small areas flanked by hedges and trees, they prefer a shallow climb out angle to aid
their escape. Thus, the taller the surrounding vegetation relative to the size of the
field or other grazed area the less likely the geese are to use it.
A number of products are currently under development which are designed
to harmlessly repel wildlife from areas where they are not wanted. Some of these products
are currently on sale in the USA and have met with mixed success. At present there is no
repellent chemical available in the UK that is approved for use and is effective against
Canada Geese. Further field testing will be required before a proper evaluation of
available repellent chemicals can be made in the future.
It may be possible to permanently alter an area where Canada Geese are
causing problems to make the site unattractive to them. Whilst the features that make a
water suitable for Canada Geese are not fully understood, enough is known about the
biology of the birds to allow a number of suggestions for habitat modifications to be
Landscaping: bank steepening and island removal
As with fencing, making it more difficult for Canada Geese to walk out
of water bodies onto feeding areas by steepening banks may encourage the birds to move
elsewhere. Avoiding shallow marginal areas which support water plants will also restrict
the food supply for the geese, but this may adversely affect other waterfowl and/or damage
the rest of the aquatic habitat. Safety concerns about having deep water and steep banks
in public areas would also need to be considered. Because Canada Geese prefer to breed on
islands, the complete removal of an island could be considered if fencing proved
ineffective in discouraging the birds. Low lying islands could be effectively removed by
raising water levels in some circumstances. As with all other exclusion or habitat
modification techniques, the effect on other wildlife would need to be considered before
embarking on such a project.
Reducing available foraging areas adjacent to water bodies by
changing ground cover.
It may be possible to reduce or eliminate Canada Goose damage to
amenity areas by changing the ground cover planting to species that are not palatable to
the geese. Ground cover plants with tough leaves, such as Ivy, and many shrub species are
not readily eaten by Canada Geese and planting the fringes of lakes with a combination of
barrier planting and unpalatable ground cover may reduce the feeding opportunities to the
point where the geese move elsewhere.
Changing cropping patterns
Where agricultural damage is occurring, it may be possible to change
the crops being grown to those less susceptible to damage by Canada Geese, or to move to
crops which are most vulnerable when the geese are elsewhere. This would obviously require
a balance to be struck between the economics of moving to a different crop compared to the
cost of either tolerating or controlling the damage being suffered. Further advice can be
obtained from the local office of the Farming and Rural Conservation Agency.
3.4.2 Population management
In situations where serious problems are being encountered and where
habitat management, scaring or exclusion techniques are inappropriate or have been tried
and have failed, it may be necessary to reduce the scale of the problem by reducing the
size of the goose population at a particular site. There are a number of techniques that
can be used for population management but all require a licence from the appropriate
authority, except for shooting in season.
The initial response to the first problems caused by Canada Geese in
the 1950s and 60s was to capture the birds during the flightless period of the
moult and to move them to other waters where there were no Canada Geese at the time. Many
of the relocated birds simply returned to their original home, whilst those that did
remain on the new site began to reproduce rapidly in the new habitat and problems soon
began to occur at these sites as well. It is thought that these reintroductions played a
significant part in the sudden rapid expansion of the Canada Goose population which is
continuing today. Because further relocations are likely to speed the geographic spread of
the species, and may also speed up population growth in newly colonised areas, it is
unlikely that licences will be granted to relocate Canada Geese in the foreseeable future.
It is illegal, under schedule 9 of the Wildlife and countryside Act 1981, to release
Canada Geese into the wild without a licence.
Shooting in season
Canada geese may be legally shot during the open season (1st. September
to 31st. January, or 20th. February on the foreshore) by authorised persons (i.e. persons
acting with the authority of the landowners and the owners of the shooting rights to the
land involved). Because they are frequently quite tame, Canada Geese are not regarded as a
very sporting shot by many wildfowlers and the numbers shot each year are
relatively small. If the hunting pressure on Canada Geese were to be increased they may
become more wary and hence offer a greater challenge to the hunter. However, it is
unlikely that winter shooting alone could reduce a large population of, for example, 500
birds by a significant amount in a single season as the increasing wariness of the birds
would make the shooting of large numbers in a single session increasingly difficult, and
the birds might simply desert the site during the winter open season, returning to breed,
and hence cause more damage, in the spring. Intensive shooting to reduce population size
has additional drawbacks in that it will disturb other waterfowl, and may not be possible
in public parks etc. for safety and public relations reasons.
Egg control (requires a licence)
Treating the eggs of Canada Geese to prevent hatching is one of the
most commonly used licensed population control techniques. It is easily carried out and
requires effort annually over a limited period. It is also generally regarded by the
public as an acceptable means of population control. Eggs may be removed from nests once
the clutch is complete, but there is a possibility that the bird will lay a second clutch.
To avoid this, eggs may be treated to prevent hatching or replaced with dummy eggs so that
the goose incubates the eggs as normal and then abandons the clutch when they fail to
hatch. There are a variety of treatment methods that may by licensed:
Egg pricking. This involves piercing the egg with a pin or
small nail and moving this rapidly around inside the egg to kill the embryo before
returning the egg to the nest. Egg pricking must be done carefully as if the bird detects
that the eggs are damaged she may desert the nest and lay another clutch.
Boiling. Eggs may be boiled to kill the embryo and returned to
Egg oiling. Eggs may be coated with mineral oil by rolling
them in a small quantity of mineral oil carried in a polythene bag. The mineral oil sold
as liquid paraffin (BP) in chemists is harmless to the birds - note this is not
paraffin fuel as used in stoves etc. The oil blocks the pores in the eggshell and
starves the embryo of oxygen. This technique is easy to carry out, 100% effective in
preventing hatching and does not adversely affect the sitting bird.
Providing that the treatment is applied early in the incubation cycle,
ideally immediately after the clutch is complete, all of these techniques are humane and
effective in preventing additional young birds being recruited to the population. However,
because of the low mortality rate of the adults, it may need 80% of all of the eggs on a
site to be treated for in excess of 8 years before egg control alone will begin to show a
reduction in population size. If nests are hard to find or manpower resources limited, egg
control alone is likely only to hold the problem at its present level rather than to
reduce it significantly.
Control of adults (requires a licence)
The quickest way to achieve a large scale reduction in the number of
Canada Geese at a site is by the culling of fully grown birds. The effect is immediate
and, if the birds can be captured during the moult, most, or all, of a population can be
removed. The principal disadvantage of this technique is that it often meets with a strong
adverse reaction from the public. The techniques require some specialist knowledge to be
used effectively and considerable manpower is needed if a large scale cull is to be
carried out effectively and humanely.
The most common way of removing birds is by capture during the moult.
Canada Geese moult all of their flight feathers simultaneously, and, for a period of four
to six weeks around the beginning of July, are unable to fly. The birds form moulting
flocks, remaining on the water for most of the time to reduce the risk of predation during
this vulnerable period. A number of small boats or canoes can be used to herd the birds
towards the bank where a funnel shaped enclosure made of chicken wire supported by fencing
stakes is erected. The funnel leads into a catching pen with a removable door. The birds
are forced up onto the bank and into the mouth of the funnel. The catching party then
drive the birds into the funnel and, eventually, into the pen and the door is closed. This
technique requires some experience if it is to be carried out successfully, and expert
advice should be sought. Smaller numbers of birds may be captured using nets or similar
devices, providing any method used does not contravene Section 5 of the Wildlife and
Countryside Act 1981, again expert assistance should be employed.
Once captured, it is necessary to humanely despatch the birds. A number
of techniques are allowed by law, but it is best to seek professional advice if a large
number of birds need to be despatched. Employing a veterinary surgeon to despatch the
birds by lethal injection or to oversee the whole operation may be advisable to allay the
concerns of the general public.
Before embarking on the large scale destruction of geese it is
important to be sure that the birds that you are removing are actually the ones that are
causing the problem. For example, birds causing agricultural damage at a wintering site
may moult at a site a considerable distance away. It should also be noted that at long
established breeding sites there may be a surplus of birds waiting to occupy breeding
territories, but which moult elsewhere. Thus, a cull of breeding birds may simply create
vacant territories for other birds to move into and repeat culls may be necessary for a
number of years before the problem is finally brought under control.
3.5 Examples Of Possible Integrated Management Strategies For Problems
Caused By Canada Geese
The choice of which techniques to use in an IMS will depend on a number
of factors specific to the site in question; these include the biology and movement
patterns of the birds involved, the severity of the problem, the timescale in which the
problem needs to be resolved, possible adverse public reaction, cost and manpower
constraints, and the need to obtain licences for some techniques. Examples of IMS that
might be developed for typical situations follow, if in doubt, the landowner or manager
should take expert advice on the development of an IMS suitable for his or her particular
A public park with an ornamental lake and lawns. A resident and
growing population of 200 Canada Geese with 15 pairs breeding on an island in the lake.
Birds range widely over the park, damaging lawns and bankside vegetation and leaving large
quantities of droppings which are fouling grassed areas and paths.
The lake shore and island should be fenced to prevent the birds walking
out to feed. If other waterfowl are present, a small gap at the bottom of the fence will
allow them to move in and out of the water whilst restricting the movement of the geese.
Consideration should be given to establishing bankside vegetation that is resistant to
damage by the geese (the presence of the fence will aid establishment or reinstatement of
damaged areas). Flutter tape or other scarers may be deployed to keep the geese off badly
damaged areas. In order to prevent further population increase, a licence should be sought
from the Department of the Environment, Transport and the Regions to treat the eggs of any
birds that breed on the island despite the fencing. The licence could be issued on the
grounds of public health and safety due to the hazards posed by the droppings in public
areas. These techniques should be monitored for at least two years in order to assess
their effectiveness. If problems persist, a licensed cull of birds may be necessary, with
sufficient birds being captured during the moult to reduce the population to the desired
level, followed by on going egg control to keep the population under control.
A keepered country estate with a large lake which is used as a
fishery and a waterfowl shoot in winter. A summer population of 200 Canada Geese with 40
breeding pairs along the lake shore. Non breeding birds moult at a large reservoir nearby
and additional birds from other breeding sites frequent the water in winter, swelling the
population to 400 birds. The geese are damaging grazing pasture and destroying bankside
vegetation which is used as nesting habitat by other waterfowl, their droppings are
thought to be polluting the water and killing the fish.
Increasing the in-season shooting pressure on the geese may be
sufficient to encourage the wintering population to move to the other waters nearby. The
estate could consider organised goose shoots which may help to bring in income. This would
need to be balanced against the disturbance caused to more desirable waterfowl
species. Visual or acoustic scarers should be deployed to protect grazing pasture from
damage during the summer months and a licence to allow out of season shooting to augment
this scaring could be applied for from the local Ministry of Agriculture Fisheries and
Food office on the grounds that the birds are damaging grazing pasture, wildlife habitat
and possibly fisheries. The summering population could be further managed by fencing the
lake edge and planting unpalatable barrier vegetation (which would double as nesting cover
for other waterfowl species). If this was insufficient to reduce numbers of breeding birds
the landowner could apply for a licence from MAFF to treat eggs to prevent hatching.
Culling is unlikely to be immediately effective in this case unless the exercise can be
carried out both on the estate lake and the nearby reservoir. A cull on the estate lake
would simply make breeding territories available to non breeding birds which would rapidly
move in, necessitating repeat culls over a number of years.
A farm adjacent to a large reservoir, part of which is a designated
nature reserve. A resident population of 600 Canada Geese with 30 breeding pairs occupy
the reservoir all year round. The birds fly out from the reservoir to feed, damaging newly
sprouted winter cereals and other crops.
The farmer has relatively few options other than shooting in season,
scaring (possibly with out of season shooting in support) or changing his cropping
patterns to minimise damage. In these circumstances, the attitude of the reservoir
managers and others with interests in managing the nature reserve (e.g. local naturalists
trusts etc.) are crucial. If the owners of the reservoir are opposed to any control action
designed to reduce the population, then the farmer is limited to the techniques described
above and may need to go to considerable effort and expense to sustain the scaring effort
needed over the period necessary to protect his crop. Acoustic and visual scarers should
be deployed and moved at regular intervals to maximise their effect. Regular shooting
during the open season may encourage the birds to feed elsewhere, especially if there are
alternative feeding sites nearby. Population management, either in the form of egg control
or culling of adult birds would only be possible with the co-operation of the owners of
5 Further Reading
ADAS 1987: Bird Scaring - Leaflet P9003 MAFF Publications
Allan J.R. Kirby J.S. & Feare C.J. (1995) The biology of canada
geese (Branta canadensis) in relation to the management of feral populations. Wildlife
Biology Vol. 1 p 129-143.
Department of the Environment Transport and the Regions (1998) Population
Dynamics of Canada Geese in great Britain and Implications for Future Management.
Report by wildfowl and Wetlands Trust and British Trust for Ornithology.
Department of the Environment Transport and the Regions (1998) Canada
Goose Research Project: Control Measures and Study of Related Canada Goose Problems.
Department Of The Environment (1994) Canada Geese - A Guide To
Legal Control Methods. National Canada Goose Working Group.
Wandsworth Borough Council (undated) London Lakes Project Overview
Document. Obtainable from Wandsworth BC price £15
How to apply for a licence to control Canada Geese
All management of Canada Goose problems must be undertaken within the
law. Some techniques, such as scaring birds away (but not from a nesting area) can be
undertaken freely, others, such as shooting birds out of season or preventing eggs from
hatching are illegal unless a special licence is obtained from the government (usually
MAFF or DETR). The law requires that the licensing authority is satisfied that there is a
significant problem and that there is no other satisfactory solution before it can issue a
licence. Licences can be issued only for the following situations:
To prevent serious damage to livestock, foodstuffs for livestock,
crops, vegetables, fruit, growing timber or fisheries.
To preserve public health or public or air safety
To conserve wild birds or to protect any collection of wild birds.
Applications for a licence to control agricultural problems should be
addressed to the nearest MAFF office (address in the telephone directory).
Applications for all other purposes should be directed to:
Department of Environment Transport and the Regions
Tel: 0117 9878903
Scottish Office, Agriculture, Environment & Fisheries Department (SOAFED)
47 Robbs Loan
Tel: 0131 2446548
Tel: 01222 825203
Applicants should expect to complete a pro forma application form or
send a letter detailing the type of damage being suffered and what measures have already
been tried to control the problem. For applications to MAFF, a site visit by a MAFF
representative may also be required to assess the nature and severity of the difficulties
being encountered. Licences are normally restricted to killing a small number of birds to
aid scaring or for treating a limited number of eggs to prevent hatching. Licences for
larger scale culls of birds are issued only in exceptional cases and after very serious
consideration. All applicants are encouraged to use the licensing scheme as part of a
wider management plan to control the number of geese present.
Central Science Laboratory
YORK YO4 1LZ