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London Waterfowl Project Frequently Asked Questions (FAQ's)

Reproduced in full

Answers for FAQs: Frequently Asked Questions

Author: Dr Debra Bourne


FAQ's contain standard answers to particular questions that managers may be asked by the Members of the Public.

This first group of FAQ's is specifically designed to support the LONDON WATERFOWL PROJECT of the Wildlife Information Network: providing support to managers of waterfowl and their habitat in the Greater London area.

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Angel Wing / Aeroplane Wing - or broken Wing?

  • A duck, goose or swan with one or both wings "sticking out" frequently has the condition known as ‘angel wing’ or ‘slipped wing’.
  • ‘Angel wing’ is a developmental problem, probably caused by too-rapid growth due to overfeeding. It is not a broken wing. A broken wing will usually droop or even trail on the ground.
  • A bird with angel wing is unable to fly. However its health is not otherwise affected and it does not suffer any pain from the condition.
  • A duck, goose or swan with angel wing, living in a sheltered environment such as a park, is safe and able to live a normal life except for being unable to fly.

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Moulting - or attacked?

  • A duck, goose or swan surrounded by large numbers of feathers and perhaps looking ‘scruffy’, but not showing any other signs of injury, is probably moulting, rather than having been attacked.
  • Most waterfowl moult once a year, usually during or just after the breeding season. Ducks that have a different plumage in the winter (breeding plumage) from the summer (eclipse plumage), moult their contour (non-flight) feathers twice a year.
  • Waterfowl cannot fly while moulting their wing feathers (except the Magpie Goose, Anseranas semipalmata) and will stay on or near the water as a safe refuge, but large numbers of lost feathers at this time does not indicate that the bird(s) have been attacked.

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Bathing - or having a fit?

  • A bird thrashing its wings in the water is probably bathing and not having convulsions (a fit).
  • If there is concern, bird can be watched for a while to see if the periods of beating its wings are separated by times when, for example, it rubs its head on its preen gland (near the tail) and preens its feathers.

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Foot on Back - or broken leg?

  • Swans frequently rest with one foot lifted up and resting on their back.
  • This is normal and does not mean that the swan has a broken leg.

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Limping - normal or in pain?

  • Waterfowl often limp for a time after they have been resting.
  • If there is concern, the bird can be watched for several minutes and it will probably be seen walking around perfectly normally in a short time.

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Gang rape’ by mallard - should something be done?

  • In spring and summer many people are worried when they see several mallard drakes in relentless pursuit of a single female duck.
  • This is, regrettably, normal mallard behaviour and happens because mallards do not make strong pair bonds and there are many more male than female mallards, particularly once most females are sitting on their nests.
  • Ducks are occasionally drowned as a result of these activities but unfortunately there are no practical methods of interfering.

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Bread/Feeding - Good or Bad?

  • The public enjoy feeding birds, in gardens or in parks. However it is important to convey the message that feeding the wrong food is harmful and can even be fatal to the very birds we are trying to help. Although small quantities of bread are alright as part of the diet of ducks, geese and swans, feeding large quantities (particularly to downy youngsters) may stop them foraging for the other foods they need for a balanced diet – like letting children eat only sweets.
  • Mouldy bread should NEVER be fed (if it isn’t suitable for "you", it isn’t suitable for the birds) and wholemeal bread is better for them than white bread is.
  • If the public can see uneaten bread lying on the ground or in the water then they should be encouraged not to give more, as too much is already being given. Uneaten bread adds to the nutrients in the water, which can lead to poisonous blooms of blue-green-algae; these may be harmful to pets and people as well as wildlife.
  • The Public should be encouraged to respect notices requesting that ducks are not to be fed the ducks, and possibly to find an alternative more suitable waterbody to feed them on - this could make the difference between health and disease for the waterbody, the birds and other wildlife such as fish in the water.
  • Alternatives to bread, such as grain (e.g. wheat) can be encouraged where recommended by managers

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Something hanging from the mouth: fishing line or pondweed ?

If a swan is seen with a piece of 'something' hanging from its mouth and there is concern that it may be a piece of fishing line, it should be watched for a while. It may just be that the swan is feeding on pondweed, in which case the weed should soon be swallowed.

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Canada Geese - Pleasure or Pest?

  • As their name suggests, Canada geese (Branta canadensis) are not native to Britain. Introduced in late 17th century they spread rapidly during the 1950s-1960s and there are now more than 60,000 in Britain. These large geese are quite friendly and many people enjoy feeding them in parks throughout London and across the country. However excess numbers of Canada geese can be a problem. In large numbers the actions of Canada geese, including grazing, can be a cause of bankside erosion and can destroy flower beds and make grass areas bare by overgrazing. Because they take in food off the water (grazing) but many of their droppings fall in the water, they increase the level of nutrients in lakes, which is a factor in the precipitation of algal blooms that can lower oxygen levels in the water, killing fish, and are also sometimes poisonous to wildlife, pets and humans. Additionally Canada geese may compete with native species for safe breeding habitats on islands in lakes and, being larger than the native ducks, might prevent the smaller birds from breeding.
  • Canada geese come into conflict with humans when their droppings soil paths, play areas etc. Although many people enjoy the geese and find them a welcome addition to the environment, others find them frightening when they approach closely, or simply find them a nuisance.
  • Despite being an introduced species, Canada geese, as wild birds under the EC Bird Directive, are protected by Section 1 (1) of the Wildlife and Countryside Act. It is illegal either to kill them or to destroy their eggs except under specific, regulated circumstances.
  • Legal methods of control which do not require a licence include:
  • scaring
  • habitat-based control including
  • removing nesting sites or denying access of such sites to geese, e.g. fencing of islands with holes in the netting allowing native ducks to get through (although this will also prevent swans from using the island)
  • using fences or low shrubs to make a barrier between open water and grazing areas. This makes the area much less attractive to the geese as they like to have a clear run from their grazing site to the water, particularly during the moult when they cannot fly.
  • preventing access to water by using netting or string over the surface (rarely practical, risks injury to geese and other birds, also unsightly)
  • discouraging feeding by the public (a site with plenty of easily-available food is naturally attractive)
  • shooting in the open season – N.B. there are public safety considerations to this as well as possible public objection and negative publicity.
  • A licence is required for:

  • - egg pricking, egg treatment with paraffin oil or egg substitution to prevent hatching
  • - rounding up and killing while flightless
  • - shooting in the close season (1 February-31 August or 21 February – 31 August below high water mark) or at any time using any sighting device for nightshooting or any device for illumination.

Licences can only be granted to:

  • conserve wild birds
  • protect any collection of wild birds
  • preserve public health or public or air safety
  • prevent serious damage to livestock, foodstuffs for livestock, crops, vegetables, fruit, growing timber or fisheries.

The Act does not allow licences to be issued if the only purpose is to prevent damage to property including amenity land.

Applications for a licence must justify the requirement for a licence, including showing that other control methods have been attempted and have been unsuccessful or are unsuitable

Control may need to be carried out over several years to be properly effective. There is no ‘magic bullet’ to solve problems with geese and a combination of several measures is usually more effective than any single action.

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Common problems which the public can help with: - How can we help the environment?



  • Discard fishing line, hooks, lead weights.

Modern monofilament nylon line does not break down but remains in the environment for years. Hooks and lines are common causes of injury in in waterfowl and are also hazardous to pets and people.

  • Discard plastic hoops/rings e.g. ‘tamperproof’ seals around milk and fruit juice bottle necks, four-pack or six-pack holders.

Depending on the size of the ring and the size and age of the bird, these can get caught through the mouth and around the back of the head, preventing eating, around legs or necks (after which they may catch on solid objects e.g. bushes, holding the bird fast) or around the body of young birds which then grow: the ring does not, with unpleasant and often fatal consequences.

  • Discard Oil and other common household chemicals down surface drains.

    Surface drains – such as those at the sides of the road or collecting your roof run-off, wash straight into watercourses. This means that oil (e.g. waste from car maintenance), detergents (e.g. the bucket of water from washing your car), other chemicals – the turpentine you just washed your paint brushes with, for example, or the last bit of your garden pesticide - will end up in your local stream or river, where it may have devastating effects.

  • Empty Milk, fruit juice, yoghurt, icecream, alcohol and any other foodstuffs, down surface drains e.g. at the side of the road.

    This adds to the amount of organic matter in the water, allowing rapid blooms of algae which lead to deoxygenation of the water and can cause massive fish kills.

Further information on pollution, preventing pollution and reporting pollution is available from the Environment Agency.

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