The Death of Birds
How long do birds live?
That's a difficult question to answer for several reasons. For one thing, most birds face a multitude of dangers that cut their lives short. Tens of thousands fly into tall buildings and towers at night when they're migrating. Hitting large expanses of glass in the daytime claims millions more every year.
One estimate is that between 90 million and 900 million are killed in this manner every year just in the United States. Millions more are hit by speeding automobiles, their broken bodies tossed to the side of the road where they are seldom noticed.
Many birds are hunted. In various parts of the United States game birds include ducks, geese, snipe, woodcock, doves, quail, and grouse to name some of the more popular targets.
In my own state of Ohio, rails can be legally hunted, even though, with the exception of the little sora rail, most of them are endangered species. Furthermore, to even get to a rail, a hunter must wade, splash, row, splatter, vrrrooom, crash, muck, and crunch his or her way through wetlands we are constantly told are fragile and endangered environments unto themselves. Untold other numbers of protected birds are indiscriminately shot by poachers and unprincipled gunners.
Humans aside, birds seem to have predatory enemies whichever way they turn. Raccoons, foxes, snakes, and rodents of one kind or another, if they aren't successful in catching an adult bird, will surely enjoy their fill of eggs or nestlings.
Bird-eating hawks such as the accipiters and falcons get their share; gulls, crows, ravens, jays, grackles, and even the tiny house wren (an accomplished egg-sucker) ravenously account for unknown millions more.
Disease takes its toll. Birds fall prey to viruses, fungal and bacterial infections, succumb to everything from encephalitis to avian malaria. Shallow warm waters with decaying vegetation is frequently responsible for horrendous outbreaks of botulism which kills tens of thousands of birds, usually waterfowl and shorebirds, at one fell swipe.
If you're beginning to realize that it's not easy being a bird, you're on the right track. Mites and dozen of external parasites, not only make life miserable for their victims, but can lead to early death.
Ingested insecticides, herbicides, and other poisons add to the thin lease a bird has on life, often lead to infertility or to deformed nestlings. In the January/February, 1997 issue of Audubon magazine, Ted Williams relates how tens of millions of American birds are being killed each year by pesticides. He was not referring to South America. He was talking the United States of America, but few people seems to care.
He tells how the United States annually "blasts itself with about half a million tons of pesticides, which cost $4.1 billion and provide fewer and fewer benefits."
The statistics are not just hard to believe, they are incredible. Williams goes on to say that despite a tenfold increase in the use of chemical insecticides since World War II, the loss of food and fiber crops to insects has risen from 7 to 13 percent.
But the damage to bird life hasn't increased. We are told that Cornell University researcher David Pimentel estimates that of the roughly 672 million birds exposed to pesticides each year in the U.S., 10 percent - 67 million - are killed. And this is considered an extremely low estimate.
Find a copy of the magazine and read the article for yourself. It will turn your stomach.
As if all that wasn't enough, natural calamities can wipe out thousands, sometimes tens of thousands of birds in a matter of hours. Hurricanes, floods, ice storms, fog, contrary winds and storm fronts encountered when birds are migrating - especially over water - take a heavy toll.
Different Orders and Families of birds have varying life spans. Basically, the rule is the larger the bird the longer the life-span.
Here are some examples of extreme longevity, and it should be remembered that these are relatively rare cases. A few herring gulls have lived to be 20 years old and there is one instance of a 30-year veteran. Twenty-two years is the record for a great egret. Twenty-three years for a Canada goose. Thirty years for a golden eagle. Thirteen and a half years for a cardinal. Eight years for a chickadee. All of these records were obtained from banded birds or birds in captivity.
In the wild, the mortality rate is much higher for young birds. A very large percent of them never make it to the end of their first year.
Fecundity is nature's way. Evolution's way, too.