few years ago I came across turtle shells for sale. I was tempted to buy
one but refrained, fearing that my purchase might encourage the killing
of the animals. Was I right, or do turtles ever shed their shells?
Rene B. Warren, Rutland, VT
Elephants don't shed their tusks, alligators don't shed their hides, and no, turtles don't shed their shells. Without them, they perish. All sea turtle populations are endangered and face an uncertain future due to extensive hunting for their shells, meat, and hides. If you buy items made from turtle shells, you're contributing to the demand for these products. Turtles, a major target of wildlife smugglers, have been called "the most profitable wild animal in large-scale international trade." Most tortoiseshell items come from the hawksbill sea turtle, a species with a showy carapace and a slow reproductive rate, which makes it especially vulnerable to commercial exploitation. Its shell brings about $100 a pound on the black market. Sea turtle products-from tortoiseshell items to turtle eggs and soup to cosmetics and lotions made from turtle oil-are prohibited trade items. Though they are protected by state, federal, and international laws, thousands of sea turtles are killed each year to satisfy the market for shell products. Worldwide, about half of all turtles (including freshwater species) are in trouble. According to Craig Hoover, who researches the turtle trade for the monitoring organization traffic, many species are removed from the wild in unsustainable numbers. The best course of action: Don't buy turtle parts or products.
Is there any birdbath that can be left out during the winter? Perhaps one made from copper?
M. Lehan, Canton, MA
Do birds have a sense of smell?
Peter R. Cope, Bellevue, WA
To some birds, the whiff of certain fragrances is like the sight of the Golden Arches: a sure sign of lunch. To others, following scents may be as good as reading a road map, since smell helps them navigate the skies. All birds possess some of the sensory equipment necessary for perceiving odors, but whether all use it is an age-old question. John James Audubon was among the first to try to find out: His experiments in 1826 convinced him that, contrary to popular opinion, vultures did not use smell to zero in on the dead animals they ate. Later research with birds such as pigeons did little to resolve the conundrum. "Think about it," says ornithologist Kenn Kaufman. "How do you know whether the bird is actually smelling something? You can't say, 'Raise your right wing if you smell this.' " Although scientists have traditionally thought of birds as lacking in the olfaction department, they have proved that many detect aromas and use them-to varying degrees-to select mates, forage, and locate nesting spots. Some seabirds, like storm petrels, recognize the odor of a compound emitted by krill, their main fare. Turkey vultures track the stench of decaying flesh to ferret out the carrion they eat. Their keen sense of smell (superior to that of other vultures) has even been exploited to pinpoint leaks in oil pipelines. When ethyl mercaptan, a chemical redolent of rotting meat, was pumped through one 42-mile line, the hoodwinked scavengers congregated at the cracks. New Zealand's flightless and nearly sightless kiwi sweeps its bill back and forth like a bloodhound to sniff out insects in leaf litter. And honeyguides, birds that often lead people and animals to beehives, can locate concealed beeswax candles.
By Carolyn Shea