Is Bread Bad for Ducks?
A very popular post on social media claims that feeding ducks with bread can be lethal to the birds and the waterways in which they make their homes.
In January 2019, the Facebook page “Wild at Heart Rescue” shared the following illustration while claiming that it is dangerous — even potentially lethal — to feed bread to ducks:
The drawings depicted waterfowl and the text said:
Please don’t kill us with bread! [image of ducks]
Bread is actually a danger to us ducks and other water birds
It causes Angel Wing which can make our feathers grow too quickly. This strains our muscles and can stop us flying.
Our friends the swans develop fatal gut and heart disease. [image of swans]
Bread is bad for our water environment. It rots, and pollutes the water.
This allows bacteria to grow and encourages rats. It causes algal bloom which gets into our lungs and kill[s] us birds.
If you want to feed us
We like lettuce, peas, and sweetcorn
At the lower, left-hand corner of the image was a crest for “Friends of Bushy and Home Parks” and a URL, fbhp.org.uk. That address led to the website of an organization formed for the protection and maintenance of two UK parks, Bushy Park and Home Park. It also introduced the possibility (not certainty) that the flyer specifically focused on ecosystems in the United Kingdom.
Nevertheless, the image spread widely on both sides of the (duck) pond. It made a number of claims: that bread is dangerous to waterfowl, that bread causes “angel wing,” that bread causes overgrowth of feathers and limited the ability to fly, that swans can develop “fatal gut and heart disease” if they consume bread, that bread is destructive to bodies of water on its own, that it pollutes water when it breaks down, that it introduces bacteria to water environments, that bread “encourages rats,” that bread causes algal bloom, and that algal bloom kills waterfowl. It also suggested that specific vegetables (lettuce and corn) are safe alternatives.
In March 2017, a National Geographic article (“Stop Feeding Ducks Bread”) covered many of the claims in the popular meme, including describing “angel wing,” which is an acquired deformity of a wing joint:
It’s junk food that offers little-to-no nutritional benefit to the ducks. “White bread in particular has no real nutritional value, so while birds may find it tasty, the danger is that they will fill up on it instead of other foods that could be more beneficial to them,” says a spokeswoman for the Royal Society for the Protection of Birds.
Reliance on human-supplied junk food keeps ducklings from learning how to forage healthy food for themselves.
A high-carbohydrate, high-protein diet is associated with a wing deformity known as “angel wing” or “airplane wing”. Angel wing is a condition where the last joint on the wing is distorted and causes the end feathers to stick out laterally—sideways—instead of lying flat against the body. This prevents the bird from flying.
Angel wing can be reversed in ducklings but is incurable in adults.
Uneaten bread crumbs attract predators, grow mold that makes ducks and other riparian critters sick, and contribute to the growth of cyanobacteria and harmful algal blooms.
Information provided by National Geographic appeared to have been sourced in large part from a March 2015 Guardian piece which echoed pleas from conservationists to stop:
The seemingly innocent act of feeding ducks with bread is harming waterfowl and polluting waterways, conservationists warned on [in March 2015] as they urged people to use more benign alternatives.
A survey by the Canal and River Trust found nearly a quarter of English and Welsh people had together fed six million loaves of bread to ducks [in 2014]. Uneaten bread causes algal blooms, allows bacteria to breed and attracts rats and other vermin.
Apart from affecting water quality, the trust and other agencies said the duck feeders may be unwittingly damaging the health of the birds.
A spokesperson for the government’s Animal and Plant Health Agency said: “Large amounts of bread and other human foodstuffs can be harmful to wildfowl, leading to potentially fatal or disabling health conditions. Uneaten food can also cause changes to the chemical and bacteriological content of water, increasing the risk of avian disease.”
A spokeswoman for the RSPB said making large quantities of bread easily available stops ducks from eating a natural, balanced diet.
Many articles on science and nature sites linked back to the Guardian article as a reference for best practices in duck feeding. However, the information put forth by the meme did not receive with unanimous agreement from wildlife experts. A statement published to Facebook in November 2018 and which appeared as an undated page on The Swan Sanctuary’s website (“Official Statement On Bread from the Queen’s Swan Marker”) maintained that campaigns to restrict bread fed to waterfowl had gone too far:
As many of you know there has been a lot of debate about feeding swans and other waterfowl bread. We have always maintained that feeding them bread is fine, Today we received a this statement from The Queen’s Swan Marker, David Barber, MVO, endorsed by Professor Christopher Perrins of the Edward Grey Institute of Field Ornithology at Oxford University.
“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.”
We’d like to Thank every one for their support and we hope that this will help these beautiful birds.
In that statement, an Oxford ornithologist and The Queen’s Swan Marker said that anti-bread campaigns are “not correct,” adding that they were “having a deleterious impact upon the swan population” (including possibly causing malnourished baby swans and grown birds, some of which were apparently engaging in harmful behavior to find food.) The statement concluded with a plea to the public to continue providing swans with bread, particularly in colder months.
On one hand, duck advocates firmly held a position that bread was harmful to swans and ducks, and that it causes wing deformities. On the other hand, an Oxford ornithologist and the Queen’s swan wrangler said that withholding bread from swans is actually harmful, possibly starving them and even forcing them to swan into traffic in a desperate search for discarded muffins.
Even if one accepts that ducks ought not to eat bread and swans relied on being fed to stay out of traffic, how could people reasonably restrict bread thrown into a body of water to one species?
People in the comments of the swan statement were also not in agreement about its various assertions and ancillary information provided to the public:
It’s quite obvious they don’t live near or know me, where I have at least 30 ducks on average 3 or 4 times a day fly down into my garden demanding food ( I live at the side of the canal. ) not only do I not have a surplus of bread, but I buy 4 loaves a week extra, just for them, plus a sack of seed once every couple of months. In fact, I feel like I’m stealing their tea when I use a couple of slices to make myself a sandwich for my lunch.
Common sense at last.
I heard that we should feed ducks/swans frozen peas!
Poor sods couldn’t open the bags.
On top of massive discord throughout the comments, an exchange appeared between The Swan Sanctuary and a concerned UK citizen. When a commenter asked if the statements applied similarly to ducks, the organization responded:
… our feeding advice applies to geese and ducks too.
Putting ducks, swans, and geese aside for a moment, the meme also blamed bread for algae blooms in bodies of water. What causes algae blooms? According to the Center for Earth and Environmental Science at Indiana University Purdue, everything… and nothing:
The development and proliferation of algal blooms likely result from a combination of environmental factors including available nutrients, temperature, sunlight, ecosystem disturbance (stable/mixing conditions, turbidity), hydrology (river flow and water storage levels) and the water chemistry (pH, conductivity, salinity, carbon availability …).
However, the combination of factors that trigger and sustain an algal bloom is not well understood at present and it is not possible to attribute algal blooms to any specific factor.
The National Oceanic and Atmospheric Association (NOAA) explained that what is essentially an imbalance of nutrients was responsible for the condition, although much is not yet known:
Harmful algal blooms (HABs) occur when colonies of algae—simple plants that live in the sea and freshwater—grow out of control while producing toxic or harmful effects on people, fish, shellfish, marine mammals, and birds.
While we know of many factors that may contribute to HABs, how these factors come together to create a ‘bloom’ of algae is not well understood.
Studies indicate that many algal species flourish when wind and water currents are favorable.
In other cases, HABs may be linked to ‘overfeeding.’ This occurs when nutrients (mainly phosphorus, nitrogen, and carbon) from sources such as lawns and farmlands flow downriver to the sea and build up at a rate that ‘overfeeds’ the algae that exist normally in the environment.
Some HABs have also been reported in the aftermath of natural phenomena like sluggish water circulation, unusually high water temperatures, and extreme weather events such as hurricanes, floods, and drought.
In that context, it seems at the very least unlikely that minute amounts of bread discarded by duck-feeding children enable algal blooms to run rampant. We were unable to turn up any evidence directly fingering bread as a factor in their spread. The State of New York issued anti-bread guidance to its residents, largely citing a number of nuisance issues (such as duck-related pollution caused by their attraction to areas where humans swim.)
Finally, regarding angel wing — does feeding bread to waterfowl lead to their development of the condition? Outside the context of advocating for or against feeding bread to water birds, angel wing remained somewhat of an enigma to wildlife experts. A 2016 study noted that as of its publication (which was after the initial “ban the bread” campaigns), researchers were no closer to determining precisely what caused the condition:
Few studies have reported the incidence of AW (IAW). Francis et al. (1967) indicated that AW in White Chinese geese was mainly due to hereditary factors; however, most studies on wild waterfowl have revealed that environmental factors are more crucial. Kear (1973) reported that inappropriate nutrition, high-protein diet, and lack of exercise were the main causes of AW in wild waterfowl. Kreeger and Walser (1984) hypothesized that AW in giant Canada geese occurs because of their rapidly growing flight feathers, with the consequent weight gain exceeding the muscular stabilization of the carpal joints; eventually, gravity pulls the wing tip outward. AW also occurs in rapidly growing birds, such as domestic and wild waterfowl fed by humans. IAW is associated with overfeeding; an unbalanced diet, including excessive protein intake; and calcium, manganese, and vitamin D deficiency (Kuiken et al., 1999). However, these results were based only on the observation of wild birds. Thus far, no rigorous experiments have been conducted for elucidating the mechanism of AW.
The meme asserted that feeding bread to ducks and swans was harmful both to waterfowl and the ecosystem, causing angel wing and algae blooms. That information was widely repeated both in the United States and the UK by conservationists and in articles, which we noticed (in a familiar pattern) tend to circularly cite one another as proof. In the wake of campaigns to discourage feeding bread to ducks, swans, and geese, other wildlife experts argued that the information was not only incorrect, but causing damage to duck and swan populations. Pro-bread experts held that their position was true for all waterfowl — and that the efficacy of “ban the bread” campaigns literally drove starving swans into active roads in search of food.
No consensus exists between these factions, but the meme also blamed bread for disease and algae blooms. Information about angel wing unrelated to campaigns discouraging the feeding of bread to swans, geese, and ducks suggested that its causes remain largely unknown. And no information we turned up on the occurrence of algae blooms suggested that bread caused them to proliferate. At this time, we rate the anti-bread meme Unknown.
However, feeding waterfowl corn and peas (as well as barley, oats, and rice along with other cereal grains and pulses) can’t hurt, either.