Wild Things: Life as We Know It
Mystery trees, loggerhead turtles and Brooklyn
- By Amy Crawford, T.A. Frail, Laura Helmuth and David Zax
- Smithsonian magazine, July 2007, Subscribe
The female fiddler crab may be attracted to the male's "sand hood" for the camouflage it offers from predators. Tae Won Kim / Ewha Womans University, Seoul
Mystery Trees Get ID
People have long known the location of earth's oldest forest, thanks to an 1869 flash flood that exposed 385-million-year-old fossilized stumps in the eastern New York town of Gilboa. But what the trees looked like was a mystery—until now. Two beautifully intact specimens, discovered a few miles from the site of the ancient forest, show that the stumps came from Wattieza trees, according to researchers from Binghamton University and elsewhere. The trees looked like modern tree ferns and grew 25 feet tall or more
Pounded by Pavement
To assess wilderness and open spaces in the lower 48, the U.S. Geological Survey has created this map. It shows the average distance to the nearest road in each county. Dark red indicates the densest road networks, dark blue the sparsest. The least roaded space per resident? Hinsdale County, Colorado, a rugged stretch of the Rockies. The most? Kings County, New York, a.k.a. Brooklyn.
Down for the Count
A loggerhead turtle has set a new world record for breath-holding by a marine vertebrate. The winning time of more than 10 hours shattered the previous record of 7.5 hours, also held by a loggerhead. Lingering in cold water may help the turtles, which are considered threatened, lower their metabolism during winter months. "There is still so much we don't know about them," says Annette Broderick of England's University of Exeter, who helped record the feat while tracking turtle migrations in the Mediterranean Sea.
Digging in
Wild wheat seeds can actually dig into the ground, according to a new study from the Max Planck Institute in Golm, Germany. Each seed has a pair of long appendages, called "awns," that are normally bent apart. When the humidity rises, as often happens at night, the awns take up water and straighten; they relax as the air dries. Tiny barbs anchor the seed in the soil and help the awns force the seed downward, putting it in a better position to sprout. It seems to be a rare case of a seed planting itself.
Observed
NAME:Uca terpsichores, a species of fiddler crab.
WHAT HE THINKS: "Look at my big claw! Look at the dome of sand I have built over my bachelor burrow! Let's mate!" (Meanwhile, a crab-eating grackle flies overhead.)
WHAT SHE THINKS: "Whew, a sand dome!" (She hides next to it till the grackle passes.)
WHAT SCIENTISTS THINK: The female's attraction to the male's "sand hood" is something new. Other sexual signals, such as a peacock's flashy feathers, are thought to advertise a male's superior genes. But the female fiddler crab, according to a study at the Smithsonian Tropical Research Institute in Panama, has a more practical and immediate motivation: she may be attracted to the male's sand hood for the camouflage it offers from predators.
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