Just watching ducks in a pond can be good for you, thanks to benefits of biophilia like reduced anxiety and increased creativity. Lots of people try to return the favor by tossing food to waterfowl, typically bread. In England and Wales alone, park visitors feed wild ducks an estimated 6 million loaves of bread every year.

Yet despite the ducks' gusto, bread isn't the best choice to feed them. It can lead to health woes like obesity and malnutrition. Too much free food of any kind may also endanger ducklings just by teaching them to beg rather than forage. Even the bread they don't eat can hurt local water quality.

Wildlife advocates in the U.S. and U.K. have been pushing this issue for years, both to protect waterfowl and the ponds, lakes and rivers where they live. In hopes of helping ducks everywhere rise above their doughy debauchery, here are three reasons why bread is not for the birds — plus a few alternative foods that do fit the bill:

1. Bread Is Crummy For Birds' Health

Treehugger / Christian Yonkers

Ducks' natural foods vary by species, but most have a pretty diverse diet. Mallards, for example, eat a mix of plants and seeds as well as insects, worms, snails and crustaceans. Bread may offer calories, but it has few of the nutrients ducks can get from their environment. And once you're full of bread, who wants to forage?

"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," a spokeswoman with the U.K. Royal Society for the Protection of Birds (RSPB) told The Guardian.

Some experts suggest that in young birds, malnutrition may lead to angel wing, a deformity in which wings jut out instead of folding up, often making flight impossible. This can occur due to a high-calorie diet, especially if it's low in vitamin D, vitamin E and manganese. The combination of extra energy and inadequate nutrients makes a bird's wings outgrow its wrist joints, causing disfigurement that's usually incurable by adulthood. The relative prevalence of angel wing at some parks is often blamed on bread.

However, other experts disagree. Professor Christopher Perrins of the Department of Zoology at Oxford University told the Swan Sanctuary, "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."

2. Free Food Isn't all it's Quacked Up To Be

Treehugger / Christian Yonkers

In addition to the nutritional issues posed by abundant bread, too many handouts of any kind raise a wide range of problems for waterfowl. These include:

Overcrowding: Ducks and geese naturally find habitats that offer enough food, but handouts can lure large crowds to areas that wouldn't normally support them. Natural foods are also widely scattered, letting birds eat in relative privacy, while competition is often fierce and stressful at artificial feeding sites.

Ducks and geese naturally find habitats that offer enough food, but handouts can lure large crowds to areas that wouldn't normally support them. Natural foods are also widely scattered, letting birds eat in relative privacy, while competition is often fierce and stressful at artificial feeding sites. Disease: Too many birds means too many droppings. That's a health risk, both in water and on land. Plus, as the New York Department of Environmental Conservation points out, "diseases generally not transmissible in a wild setting find overcrowded and unsanitary conditions very favorable."

Too many birds means too many droppings. That's a health risk, both in water and on land. Plus, as the New York Department of Environmental Conservation points out, "diseases generally not transmissible in a wild setting find overcrowded and unsanitary conditions very favorable." Delayed migration: Artificial feeding has been known to shorten or even eliminate migration patterns of waterfowl. They may be reluctant to leave a reliable food source despite the onset of winter, and then struggle to survive as temperatures fall — especially if the cold discourages their human feeders.

Artificial feeding has been known to shorten or even eliminate migration patterns of waterfowl. They may be reluctant to leave a reliable food source despite the onset of winter, and then struggle to survive as temperatures fall — especially if the cold discourages their human feeders. Expectations: Our gifts may also spur a few other negative changes in birds' behavior. When adult ducks become obsessed with free bread, for example, they may fail to give their ducklings a sufficient education in foraging, thus committing them to a life as beggars. Once birds are dependent on handouts, they tend to lose their fear of humans and behave more aggressively.

3. The Leftovers Have a Ripple Effect

Treehugger / Christian Yonkers

Some of the bread we toss to waterfowl inevitably escapes their grasp. If enough calorie-rich foods accumulate in a pond, they — along with all those extra duck droppings — can trigger algae blooms that deplete oxygen from the water. Known as hypoxia, this can wipe out pond life and rob birds of natural food supplies.

On land, any moldy leftovers lying around could be particularly dangerous if ducks eat them. This is also a risk when people feed ducks bread that has already spoiled, and as biologist Steve Carr recently told CBC News, it's potentially fatal.

"[W]hen it goes bad, it has that little green mould in it, and that mould actually causes specific diseases in ducks," says Carr, a professor at Canada's Memorial University. "It causes lung diseases, so it's not just nutritionally bad — it can just kill them outright."

Treehugger / Christian Yonkers

None of this means it's necessarily wrong to feed waterfowl. The main lesson bird experts and wildlife advocates want to convey is moderation, which means limiting the size of handouts as well as avoiding ponds where lots of other people already toss food. A little bread might even be OK now and then, although several other human foods come closer to providing the right mix of energy and nutrients.

In fact, the Swan Sanctuary points out that many birds rely on handouts, and anti-bread campaigns have caused them to lose weight and wander into the roads searching for food.

Even the Queen’s Swan Marker, David Barber, who is in charge of the UK's swan welfare and information, weighed in:

"Swans have been fed bread for many hundreds of years without causing any ill effects," he said. "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."

Many conservation groups however discourage feeding wildlife at all, and for good reason. But some also offer lists of alternative snacks that are less harmful to ducks and geese, hoping to at least improve the food if they can't prevent the practice entirely.

Treehugger / Christian Yonkers

So, if you still feel compelled to feed your local ducks, try these instead of bread: