Wild Things: Life as We Know It
Squid light shows, monkey hugs and chickadee alarms
- By Smithsonian magazine
- Smithsonian magazine, May 2007, Subscribe
Choosing Sides
Certain Southeast Asian snakes are endowed with more teeth on the right side of the jaw than on the left. To what advantage? A new study from Kyoto University in Japan shows that the tooth arrangement helps the snakes grapple with their favored prey, snails. Most snail shells grow in a clockwise direction, so their openings are wider on the right side when tipped over by a snake. An attacker with extra teeth on the right side can both hold the shell firmly and extract the meaty snail efficiently. But even such a cunning adaptation can be thwarted. When faced with the rare snail whose shell formation is counterclockwise, many snakes failed to feed or dropped their prey.
Illuminating
Previously thought to be sluggish and dull, the eight-armed deep-sea squid Taningia danae actually puts on an exciting light show. Researchers from three Japanese institutions made the world's first video of the squid, which can grow more than seven feet long. It shows that the squid's arms emit light just before seizing bait. The flash, researchers say, might startle prey or help the squid aim its attack. Also, some squids glow intermittently, which the researchers speculate is a form of communication, possibly as part of courtship or mating.
Mutual Assured Hugging
Displays of affection keep the peace among spider monkeys, according to a yearlong study in the Yucatán. Spider monkeys spend most of their time sorted into small groups of about 2 to 20 members. When two different cliques come together, members of both groups often chase and fight each other. But clashes are less likely to occur if one or two rival monkeys embrace. We call it cute; the researchers call it an unusual example of conflict management.
Very Early Childhood
An ancient dental record is adding new depth to early Homo sapiens' evolutionary history. Researchers from the Max Planck Institute and elsewhere used an X-ray technique to analyze the fossilized jaw, found in Morocco, of a 7-year-old human who lived 160,000 years ago. The pattern of lines etched into the enamel at growth intervals resembled that of a modern child. Conclusion? Even in humanity's earliest days, childhood was more prolonged than it is among our primate cousins, demanding lots of care—and possibly social organization.
Observed
NAME:Sitta canadensis, or the red-breasted nuthatch.
RECENTLY SEEN: Cracking the code of the blackcapped chickadee (Poecile atricapillus).
THEY'RE ENEMIES?: No. They help each other out.
HOW'S THAT?: Chickadees sound alarm calls—"chick-a-dee"—that vary in speed and the number of "dee" syllables depending on the threat. New research by scientists at the universities of Washington and Montana has found that nuthatches can decipher chickadee calls—the first known example of such sophisticated interspecies eavesdropping. When chickadees warn that, say, an agile owl is nearby, the nuthatches join forces with them and surround the predator, which happens to be both species' best hope of driving it away.
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