Xrhrft

There is this image going around:

which claims that bread is bad for ducks and swan, and that you should feed them lettuce, peas and sweetcorn instead. Is there any truth to this and are there any reliable sources?

I can't comment specifically for ducks, but I will quote the Official Statement on Bread from the Queen's Swan Marker (who has responsibility for swans in the UK):

There has been a great deal of press coverage in recent months regarding the ‘Ban the Bread’ campaign which is confusing many members of the public who like to feed swans. Supporters of the campaign claim that bread should not be fed to swans on the grounds that it is bad for them. This is not correct. Swans have been fed bread for many hundreds of years without causing any ill effects. While bread may not be the best dietary option for swans compared to their natural food such as river weed, it has become a very important source of energy for them, supplementing their natural diet and helping them to survive the cold winter months when vegetation is very scarce.

There is no good reason not to feed bread to swans, provided it is not mouldy. Most households have surplus bread and children have always enjoyed feeding swans with their parents. The ‘Ban the Bread’ campaign is already having a deleterious impact upon the swan population; I am receiving reports of underweight cygnets and adult birds, and a number of swans from large flocks have begun to wander into roads in search of food. This poses the further risk of swans being hit by vehicles. Malnutrition also increases their vulnerability to fatal diseases like avian-flu which has caused the deaths of many mute swans and other waterfowl in the past.

Furthermore, there have been statements made in the media claiming that feeding bread causes angel-wing in swans. Angel-wing is a condition where a cygnet develops a deformed wing. Professor Christopher Perrins, LVO, FRS of the Department of Zoology at Oxford University stated, ‘There is no evidence of a connection between feeding bread and angel-wing; at least some cygnets develop this condition without ever having seen any bread’.

I therefore encourage members of the public to continue feeding swans to help improve their chances of survival, especially through the winter.

See: http://www.theswansanctuary.org.uk/cause/official-statement-bread-queens-swan-marker/

Which I would consider fairly conclusive in the advice to absolutely avoid bread being incorrect. It seems likely that there are better things to feed the birds that bread (it is easy to buy special bird food, which my wife does), but that is not the same as saying that bread is bad.

To address the feeding of ducks:

Ducks Unlimited Canada has this to say:

I’VE HEARD THAT FEEDING DUCKS BREAD IS BAD. WHAT SHOULD I FEED THEM?

DUC does not recommend feeding ducks. It increases the chances of
negative human/wildlife encounters and can make them dependent on
people for food.

The Canadian Wildlife Federation has a similar suggestion:

Can I feed ducks bread?

The short answer to this is no.

Ducks naturally eat a nutrient-rich diet that may consist of insect
larvae and other aquatic invertebrates, small fishes, amphibians, as
well as seeds and aquatic plants. Bread and similar products such as
chips, donuts, popcorn and crackers provide very little nutritional
value.

Ducks that are regularly fed bread can become malnourished, aggressive
towards one another, may lose their foraging instincts and can lose
their natural fear of people.

Also, bread that isn’t eaten can result in nutrient build-up and
increased algae growth.

Feeding wild ducks is a practice CWF does not encourage. They may look
cute, and a bit of bread might get them flocking towards you, but
feeding them is doing more harm than good.

So, at least over on this side of the pond, the experts seem to be recommending that humans don't feed anything at all to ducks.