There is an artificial lake near my home here in southern CA. Ducks, geese and other assorted water fowl make their home there. Signs posted around the lake warn of fines if one is caught feeding these birds.
How does the bread my daughter feeds these birds harm them? Or does this feeding serve to attract more water birds to the point where the population exceeds the lake’s capacity to process all the poop? I’ve also heard that the bread expands in their stomach and eventually kills the birds.
First off, it’s not good to get a wild animal hooked on people food. It messes with their natural forage instinct. Secondly, white bread isn’t good for wild animals (or people for that matter) all those preservitives and enriched flours are unhealthy for any animal. Would you happily feed deer Twinkies? I think not.
The problem is habituation. Wild animals fed by the public learn to think of people as a source of food rather than something to be feared and avoided. Since humans are actually the most dangerous animals out there, this leads to a lot more dead habituated animals.
On top of that, the animals become dependent on humans for food, causing them to lose their foraging and/or hunting skills. Human cycles of feeding often differ from natural food cycles, leading to more dead animals. Imagine animals continuing to be fed past the point when they would have to migrate in a snowbound place.
Also, habituated wildlife become pests, threatening humans and property. I’ve seen several cars broken into by bears in Yosemite, but a less dramatic example is that recently habituated turkeys in Massachusetts have taken to aggressively pecking at people in attempts to get food.
Ask your local park ranger or fish & game dept. for more detail on local conditions, usually they’re happy to get the word out.
Man can not live by bread alone, and ducks don’t do much better. Bread just does not have enough nutrition, just a bunch of empty calories, and the ducks litterally starve to death (much like the tribbles in the quadritridiacalie).
Should’ve mentioned that we buy whole wheat bread for them, but its true that they probably need more than just bread to eat.
I wonder what they would forage on around here in southern CA. There aren’t any grain farms around. Strawberries, avocados and lemons are the only local crops.
I think most of the water fowl at the lake have given up migrating. It seldom drops into the 30’s here so there is no real winter to get away from. Not that this is a good thing. Its probably if they do leave and find mates from other areas to keep the bloodlines healthy.
I’ve seen signs that say that while feeding the birds is ok, one should take care not to throw bread in the water. It is a good material for nasty things to grow on and can contaminate the lake.
Also, all of those water fowl attracted to one pond can really foul it up with bird shit. They dredged a local pond (a natural formerly brackish estuary) and drained it due to all of the bird shit. Of course this may be just a front for the reason it’s simply not good to teach animals to come to people for food (a big problem with the local fat little ground squirrels).
California used to have extensive wetlands, such as the great Lake Tulare, which was a shallow lake that previously was the largest lake in California, before it was drained (this lake used to occupy much of the southern end of the Central Valley. It made an appearance in 1997 during a very wet winter). A lot of these birds will find reservoirs, retention ponds, or agricultural retention ponds to forage in. They also find rivers which are more or less still natural, and natural ponds and lakes.
I have a book that says locally (the Monterey area), these man made ponds have increased forage and habitat areas for wildfowl. Outside of the cities there are still perrenial streams and rivers which these waterfowl would forage among.
Here’s a map showing all of the regions in California where one finds vernal pools (seasonal winter rain fed ponds): http://ceres.ca.gov/wetlands/geo_info/vernal_pools_map.html
A good guess:
Many of the birds would’ve naturally moved on once these ponds dried up, but from winter through early summer, these ponds provided good habitat. Migratory waterfowl would’ve been attracted to these ponds during trips south. During the dry months they’d have searched for lakes that last year round. It is the fact that there are manmade ponds and lakes that waterfowl are found year round in arid climates like Southern California.
As for diet, ducks are usually omnivorous and opportunistic, meaning they get what they can. Naturally, if people are feeding them bread, they’ll take that opportunity and subsist on that alone. They aren’t strictly grain eaters, they usually subsist on water plants and aquatic insects.
Even whole grain bread isn’t that great for them since they also eat insects along with plant matter. I believe that the ducks used the wetlands of California to forage for the coming trip north to the arctic (at least the pintails do).
Ducks migrate. That involves multigenerational patterning on the stimuli and responses that initiate leaving, and returning to specific locales. Add a ton of bread, and you change the duration of a single migratory stop for a large number of ducks. Now those ducks don’t migrate in the same pattern, and have no elder leaders to follow. So, they stay where they are. The following years the balance between ducks and habitat are much different, due to the ducks that winter over, and the predators and parasites that have been able to establish year round population growth.
Your bread kills more ducks than it supports, over the long run.
Tris
When I was hiking at Philmont, we had a saying about why you shouldn’t feed the local bears:
“A Fed bear is a Dead bear. Yes, the food here is THAT bad.” 
I’m not sure why, but this has to be the funniest mental image I’ve had in some time.
I hate to do this, but I’m pretty sure it’s spelled quadratriticale. Triticale is a real hybrid cereal.
Sorry.
I think another thing to keep in mind is that while you may be feeding the ducks bread (the benefits/risks of which everyone else has already covered), that doesn’t mean everyone else is. I’ve seen plenty of people throwing all kinds of bizarre foods out to the ducks - fritos, M&Ms, pieces of KFC…
Is there any proof that a bird, previously adept at providing for itself, once hooked on people providing it with bread, loses its ability to hunt when the artificial food source is removed?
It’s because the ducks get over-familiar, and lose their natural fear of humans. Before you know it, you’ve got a maneater terrorising the whole duck-pond area.
The habitution and diet issues have been covered pretty well, while the pollution issue has received less attention: it is a problem.
At the lake where my folks lived for 39 years, when we first moved in, geese and ducks were rare visitors and everyone was interested in feeding them to have them picturesquely swim by their houses. Within 12 years, with increasing problems of keeping the lake clean (both regarding coliform count and keeping down weed growth), the DNR was asking, then ordering all the residents to stop the feeding. During a couple of summers, swimming was prohibited, despite the fact that the lake was fed both from a stream and springs and that it had an open outlet. Waterfowl may have a better tolerance for waste (although I doubt it), but even if the rules are made to make the water extra safe for humans, that much fecal matter (in the lake and in the run-off from shore) cannot be good for most critters.
What’s the purpose of the artifical lake? If it’s a retention pond dug to hold excess rainwater as you usually see in subdivisions and corporate centers, there’s probably no noble reason for the signs – they just want to discourage having duck and goose poop all over. Geese in particular are extremely obnoxious when it comes to that as well as having some aggressive traits.
That’s not to say that the other reasons aren’t good ones. But the Homeowners Association of Oak Place Subdivision is more concerned with keeping their sidewalks cleaned than the starvation of waterfowl. Unless, of course, the ducks die on the sidewalks 
On the other hand, if the signs are from the local muncipality and the lake is in a park or something, it may be a bona fide concern for the birdies.
I’ve taken my son to the Riverwalk in Naperville, IL on several occassions to see and feed the ducks bits of whole wheat rolls. The problem is that everybody feeds the ducks and you wind up with a bunch of fat, indolent mallards that can’t even be bothered to walk four inches and eat the bread you just threw. It was more entertaining to see the sparrows and finches come down to eat the crumbs.
There are enough waterfowl here that all of the perennial lakes here have high coliform bacterial counts. High enough there are signs warning people to not even touch the water. The pond here in town is clear, but enough ducks and geese live in it that it’s just incredibly dirty.
I’m not going to provide a cite, but I volunteer at a marine mammal rehabilitation center. We find that the mammals suffer from loss of foraging skill in as short a rehabilitation stay as three months unless we put them through “fish school.”
I’d be surprised if birds did much better. Think of it this way: I haven’t played basketball in over a year. Wouldn’t it be surprising if I returned to the court just as good as I was last time?
Some people say: Oh, but animals have instinct. Anyone who has watched young birds or young mammals feed can tell you considerable learning takes place and that a practiced bird is much more adept. The problem isn’t presence/absence of feeding skill, but one of degree. Poorly practiced birds are more likely, but not certain to fail in a lean year.
The only caveat I’ll add is that ducks have a far simpler feeding/foraging problem to solve than sea lions do. I suspect degree of skill is considerably more important in the sea lions.
We have a man-made pond here, with ducks and geese. My understanding of why we are discouraged from feeding the birds is that if you feed them, they’ll lay more eggs than the habitat can really support. Then either some of the ducklings and goslings will starve, or the natural food sources will be depleted.
Basically a “don’t get the ecosystem out of whack” message.