Bird-watching Myths

by Eirik A.T. Blom

What sociologists call urban myths, persistent stories that fill a cultural need, have always been with us, but with the Internet moving "information" around the world at the speed of light, they have taken on new life. New myths arise every day and spread so rapidly that there is no chance to rebut them. Among the most persistent are the baby/cat/small dog in the microwave and alligators in the sewers. Although there is no evidence that any of these things ever happened, the stories stay alive, repeated thousands of times a day somewhere in the country.

Bird watching has its own set of myths. I have been monitoring the Internet discussion groups about birds for a year, and no matter how many times certain myths are debunked, they continue to appear, and there are always a few folks ready to believe them and pass them on. The following ten are among the most persistent, some of them popping up every few months.

What they all have in common is that they are not true. Entertaining for sure, but not true. If you hang around bird watchers you are going to hear at least a few of them. If you hear any of these, jump right in and set the record straight. But please, please, don't send me any letters saying you know someone who knows someone who heard something from a friend's sister that makes one of them true. If you think one of these is true, track down the information. My bet is that it will be a dead end, but I've been wrong before.

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1. You should not throw rice at the bride and groom at weddings because birds eat it and it swells up in their stomach and kills them. Sometimes the myth goes that it causes them to explode.

Not true. If it were, there would be exploding bird stories all over the national press every June. Think about it. Lots of birds feast in rice fields every year, irritating rice farmers to distraction. If eating rice caused birds to explode, most rice fields would look like a popcorn machine in the harvest season, with little puffs and explosions providing constant entertainment. Quite a vision, and one that the press would never miss.

And there is no difference between rice in fields and rice in bags from the supermarket. Birds have no trouble digesting rice, or any other "expanding" vegetable. I am all in favor of throwing birdseed at weddings, which is what proponents of this myth urge as a solution. I like the symbolism of throwing birdseed. But rice is fine, too.

2. You should take down your bird feeders in the fall because they keep birds from migrating and these birds will freeze to death.

This one will not go away. I have seen it raised on the same discussion group as many as five times in two months in the fall. It makes a little more sense than most other myths because most of us who feed birds have seen a lingering individual at one time or another. From that we leap to "If the feeder weren't here, the bird wouldn't be either."

The problem is that the leap jumps over the facts about bird migration. Virtually all long-distance migrants, at least all the ones that cannot survive the winter in North America, move in response to genetic and environmental forces. Warblers and vireos and flycatchers pack up and head for the tropics every year not because they are running out of food, but because winter is coming. Their migration happens at a time when there is a wealth of natural food available, enough to fatten them up for the rigors of the journey.

The ones that stay do not do so because there is food to be had; they stay because there is a glitch in their genetic makeup. If, having failed to follow the rest of their tribe, they don't go, they may end up at a feeder because there is no other food to be had. The hard truth is that the vast majority of the birds that fail to migrate die. But it is not because of feeders. Feeders probably extend, briefly, the life of a few of them.

This is also true of hummingbirds, a favorite group among proponents of the "take down the feeder" philosophy. Look at it logically. If feeders were so powerful a magnet that they could undo uncounted years of evolution, there would be tens of thousands of ruby-throated hummingbirds trying to winter in the eastern half of the continent because there are that many feeders.

So keep those feeders up if you enjoy watching the birds. You are not "seducing" any bird to linger beyond its time.

3. Hummingbirds migrate by riding on the back of geese.

This is one of my favorites, but I am amazed by its durability in the face of all common sense. The "evidence" is all anecdotal, and it is impossible to track down anyone who has proof. That's because there is none. Forget for the moment the unlikelihood of this cooperation. Look at the migration of hummingbirds and geese. Except for a few birds in a small area of the country, there is virtually no overlap in the migration pattern and timing of geese and hummingbirds. Most hummingbirds are long gone before the first geese come out of the Arctic. Any ruby-throated or rufous hummingbird waiting for the goose train to take it to Central or South America is in trouble.

4. Exploding gulls.

Another exploding bird myth. I wonder why we are so attached to myths where something blows up. Must be the drama.

This myth proposes that if you feed a gull an Alka Seltzer tablet it will swallow the offering and when the lethal charge gets into the stomach and dissolves, the expanding gasses will cause the bird to explode. Every year there is another story about some mean kids doing this. Oddly, it always involves New Jersey.

After you stop giggling at the image of gulls exploding like flying land mines all over the Jersey shore, the unlikelihood of the myth starts to intrude. If it were true, it would be a big story. I can see the coverage now: Dan Rather in his safari jacket, standing on the windswept coast, hair blowing in the wind, gull feathers raining down in the background; PBS specials (who can resist the vision of a gull, cheerfully flying along and then suddenly exploding, right in front of the camera?); exposés in the tabloids.

If the body could not handle a little Alka Seltzer without an explosion, it wouldn't be legal to sell the stuff over the counter. If it caused gulls to explode, there would be a rash of reports every year. I do not know the physiological process by which the body processes a tablet swallowed whole (and I have no interest in trying), but I assume it involves, among other things, a fair amount of belching and a slightly gassy feeling. Actually, if I ate some of the stuff that gulls do, I would be thrilled to have a little relief, but they seem to do fine without it.

5. Red dye in hummingbird nectar is good/bad.

Whew! Few debates generate as much passion as this one, and if you are a survivor of an argument on the subject, you are only too aware of the battering you take. The problem is that there is absolutely no evidence either way. None.

First, let's deal with the argument that red dye is good because it increases the attractiveness of the feeder. Sounds good, but hummingbirds are not attracted to the color of the nectar; they are attracted to the color of the feeding port, that little plastic who-didgey that looks like a flower. There are a few studies on color preferences and feeding of hummingbirds, but no proof that the color of the nectar matters.

Second, there is the argument that it is bad. The story, which will not die, is that the dye causes a variety of diseases. The most persistent story is that it causes liver damage, and proponents trot out the fabled story of the study done at the San Diego Zoo a few years ago as proof. The problem is that there was no study. It is a myth. There is not a single piece of proof that the dye causes problems.

Each side has its passionate advocates. But until someone comes up with real evidence one way or another, be skeptical of "studies" and other proofs thrown casually into the debate.

6. The stepped-on rail.

This myth has many incarnations. The core of the story is that a group of bird watchers was using a tape recorder to lure a rail into view and then one of the participants, failing to pay attention, stepped on and squashed the bird.

The variations are many, and it is the variations that help keep the story alive. In some cases the bird is a yellow rail, in some cases a black rail. One version involves a tour group led by a famous birder. In another, the squashing occurred during a government survey of endangered species. In one version, the bird was stepped on just before a dying bird watcher, whose last wish was to see the species, could add it to his/her life list. In another, the bird flew out of the marsh and toward the group and one person panicked and swatted it out of the air, breaking its neck.

I suspect that this myth rises out of the passion over the use of tapes and the slightly irrational anger some folks feel toward lists of any kind. The problem is that no one can provide any evidence that it happened. No names of participants. No sworn statements. A few have claimed to have been there themselves, but they have not been able to come up with a list of other participants who will support the claim. The story is more believable because most of us think that somewhere, someplace, somebody has probably stepped on a rail, and there are just enough stories about tape abuse to make the story more appealing. But so far, this is only the stuff of legend.

7. Purple martins regularly eat 2,000 mosquitoes a day.

Don't, don't, don't write me letters about this! If you have martins, and believe they have substantially reduced the number of mosquitoes around your house, I am happy for you. Enjoy. I love martins and have had martin houses when I could. I encourage everyone to have martin houses. I am a fan.

But. The 2,000-mosquito-a-day figure is one of the most frequently cited "statistics" in the world of birds. The problem is that there is very little evidence that it is true. It is based on a single bird, taken early in the morning over a salt marsh, which had 300 mosquitoes in its belly. From that it was extrapolated that it would have eaten at least 2,000 if it had kept going at the same rate all day. That case is the one that is cited when defenders of martins as mosquito control agents are asked for evidence of the claim. That is the only evidence.

On the other side, there are several studies that show that mosquitoes are only a small part of a purple martin's diet. Those studies show the birds taking a large variety of flying insects, most of them considerably larger than a mosquito. Those studies also show very few mosquitoes in the diet.

There are some reasons why mosquitoes should typically make up only a small part of a martin's diet. First, mosquitoes are primarily nocturnal. Not exclusively, but primarily. Martins are primarily diurnal. Martins and mosquitoes are both active at dusk and dawn, and undoubtedly the birds take some of the little pests, just as they take almost everything that flies. But if you live where there are a lot of mosquitoes, you know that the real agony starts when the sun goes down.

Virtually no pest is as maddening in relationship to its size as a mosquito (although chiggers give them a hard run for the money). The fact is that mosquitoes offer virtually no nutritional benefit, certainly not enough to make it worth the martin's time to actively pursue them as a primary item in the diet. I do not doubt that martins will scoop up one if they come across it during their foraging, but imagine how much energy it would take to catch enough to feed not only themselves, but their young as well. It does not make biological sense.

I repeat, do not shower me with letters proclaiming that martins have brought you a mosquito-free life. I have read hundreds of them. If you are passionate about this, go to a good ornithological library and compile the studies on martin diets. Except for that one bird, they all show that martins take very few mosquitoes. Even if they do grab the occasional mosquito snack, the 2,000-a-day figure is a figment.

8. Small birds are carried long distances by powerful storms.

This one has a number of variations. A vagrant from the West shows up in the East. Immediately, speculation starts. How did it get here? It could not be deliberate. Then someone notices that a few days before it was found a fast-moving storm with 60-mile-an-hour winds swept across the Midwest. Aha! The bird was blown here!

Not likely. All those who have had the misfortune to find themselves doing a Christmas Count, or a May Count, or any other bird count on a day when the winds exceed 25 miles an hour, know that high winds do not blow small birds around; they ground them. In a high wind, a small bird will almost allow itself to be picked up rather than fly. Which makes sense. A bird weighing only a few ounces simply cannot deal with winds that strong. In the few instances when you see one trying to fly in high winds, it goes a short distance and plunges to earth.

Highly aerial birds, like seabirds and gulls and terns, are well-adapted to high winds, but small passerines are not, and they must hunker down when the gales blow. Why some birds deviate dramatically from their expected course is a subject of intense debate, but pending the presentation of any proof, any proof at all, the "blown across the country by a gale" theory should be retired.

9. Parent birds will abandon a nestling if it has been touched by humans.

This is an amazingly popular myth despite the massive amount of evidence to the contrary. Think about the thousands of studies that involve monitoring nests, weighing and measuring the young. Consider that most of those nests are successful and that the adults return as soon as the intruders are gone. Factor in the millions of baby birds that are banded and fledge successfully. Remember the tens of thousands of bluebird boxes.

If birds were repelled by the scent of human beings and fled if their odor appeared on the nest, there would be wholesale abandonment of nests every year. Yet this myth persists, a "truism" handed down from generation to generation. Its origins may lie in the fact that human scent can be disruptive to birds' nesting success. It is not birds, it is mammalian predators that follow scents, and if you approach a nest too often, or too closely, you may well be leading a predator to the site. The next time you visit, the nest will be abandoned. Voila! The birds smelled you and ran.

There are very good reasons for staying away from bird nests. Birds may find your intrusiveness offensive for many reasons, but one of them is not the way you smell.

10. Some birds mate for life.

It sounds so sweet, doesn't it? So, well, human. The idea appeals to our sensibilities and our morality. The problem is that it has virtually nothing to do with humans or birds.

Mating for life is an ornithological shorthand that stands in contrast to those birds that change partners every year, or even several times in the same year. It does not necessarily mean what we think it does, however. Even those birds that "mate for life," like some of the larger waterfowl, are not practicing matrimony the way most of us would like to think it ought to go. It merely means that, all things being equal, these birds will stay with the same mate for an extended period. It does not preclude a variety of reproductive strategies, including what scientists like to call EPFs (extra-pair fertilization) and what most people would call a fling. The recent advances in DNA testing have shown that, almost everywhere, parentage is a more complicated and less certain fact than previously thought.

Some individuals do mate for long periods, perhaps even until one of them dies, but mating in the bird world is as varied and messy as it is for human beings.

Bird-watching myths die hard, if at all. As a philosophical wit once explained, a lie is halfway around the world before the truth gets started. The myths discussed here, and others, will never be rooted out, but you can be aware, and provide a counterpoint to many of them. Be prepared for the results. No one likes a favorite myth debunked, and wars have been fought over myths. The trick is to be rational, friendly, and non-threatening.

How do you separate the myth from the reality? It is not always easy. There are extraordinary and improbable stories about birds that are entirely true. The trick is to develop a silent alarm system, a little buzzer than goes off when the story is too good, too weird, too improbable. Don't reject it out of hand, but investigate. Ask other bird watchers. Post a question on the Internet. Go to the library.

Do not, however, allow an appropriate sense of skepticism to interfere with the ability to discover wonderful things, to be moved and awed by the reality of birds. There is a lifetime of pleasure in the contemplation of birds, even without the myths.