Ask Audubon

The following questions are culled from dozens sent in by seniors in the ecology and field biology class at Chaminade College Preparatory School in St. Louis, Missouri, at the behest of their teacher, Tim Pendleton. He uses Audubon as an educational tool.

By Carolyn Shea

Do eagles remain faithful to one mate their entire lives?

--Pat Webster

Bald eagles stay hitched until death do they part, often returning year after year to the same nest. While there, the pair continuously adds to the structure, so that after many seasons it assumes gargantuan proportions and stands as a symbol of their fidelity. In Vermilion, Ohio, one behemoth, used for more than three decades, measured 9 feet across and nearly 12 feet high, and was estimated to weigh more than 2 tons.

Though the birds' courtship rituals are spectacular in their display of aerial acrobatics, it is nest building that cements the bond between male and female. Dad's contribution to his progeny doesn't end at conception: He sticks around to help incubate the eggs and feed the offspring. Bald eagles, which are capable of breeding at about 4 years and have been known to live to 28 in the wild, are not unique in their sexual liaisons. According to Frank Gill, Audubon's senior vice president of science, more than 95 percent of bird species are monogamous, making them among the most loyal members of the animal kingdom. Recent research, however, is yielding evidence that philandering may be more prevalent than previously supposed. "The general rule emerging," says Gill, "is that sexual infidelity is common in socially monogamous species."

Are we using less paper, thus cutting down fewer trees, because of the Internet?

--Kyle Schnettgoecke

At the dawn of the electronic information age, futurists predicted that the computer would usher in a paperless society, a world in which all commerce and correspondence would be recorded, transmitted, and archived electronically. Well, things haven't turned out quite as expected. With tens of millions of computers now in use, the world's appetite for paper has grown more ravenous than ever. Fax machines, printers, and copiers make it possible to churn out page after page after page. Globally, paper use has increased more than sixfold over the past five decades. One-fifth of all the wood harvested in the world ends up being manufactured into paper, a process with environmental costs ranging from deforestation to species loss to pollution. The United States, with less than 5 percent of the planet's population, uses 30 percent of its paper. Annual U.S. per capita consumption is roughly equivalent to 670 copies of the daily New York Times. In 1997 we went through a total of 89.9 million tons. It takes two to three and a half tons of trees to make one ton of paper. Not only do we consume the most paper, we also throw out the most--more, in fact, than China, the second biggest consumer, uses in a year. About half ends up in landfills. To cut waste, the conservation group Forest Ethics recommends consciously reducing the amount of paper we use in our business and personal lives, and using "tree-free" paper made from ecologically sustainable fibers such as kenaf and hemp. In addition, buy recycled paper with a high percentage of post-consumer content (the amount that comes from recycled materials). While not entirely paperless, such efforts would relieve pressure on our forests in the Internet age.

Why are electric eels electric?

--Norman Stoddard

Understandably among the most feared of South American creatures, Electrophorus electricus is essentially a swimming battery packing a cattle-prod-like zap. Native to the Orinoco and Amazon river basins, the electric eel is not really an eel at all but an eellike fish. In its tail, which makes up about four-fifths of its body, are three current-producing organs consisting of electroplates--modified muscle cells. These organs line up in a column, much like the Duracells powering your flashlight.

Depending on its size--and some reach nearly six feet--one of these live wires can hold up to 6,000 electroplates, each of which generates about a tenth of a volt of electricity. With its limited eyesight, the fish uses its heavy-duty circuitry to navigate the murky waters it typically inhabits, as well as to communicate with others of its kind, defend itself against foolhardy predators, and catch its meals, which consist mainly of fried fish. Provoke nature's most electrifying creature and you could be in for a 600-volt shock. That's about five times the voltage emitted by a light socket and strong enough to disable a computer without a surge protector. Not to mention knock out your lights.

 

© 2001  NASI

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