Wild Things: Life as We Know It
Great sharks, manakins and dino digs
- By Smithsonian magazine
- Smithsonian magazine, June 2007, Subscribe
Great sharksblacktips, great whites and other species longer than six feethave been hunted almost to extinction in places. iStockphoto
Outfoxed by Climate Change
Animals don't always cope with shrinking habitat, say researchers from Stockholm University and other institutions. They compared DNA from modern foxes in Scandinavia and Siberia with DNA extracted from the teeth and bones of ten arctic foxes that lived at different latitudes 12,000 to 19,000 years ago. They found that today's animals are descended from the northernmost arctic foxes. Why? Animals in southern ranges were apparently wiped out when the last ice age ended about 10,000 years ago, shrinking the amount of territory suitable for the cold-loving foxes.
How Sharks Help Scallops
Great sharks—blacktips, great whites and other species longer than six feet—have been hunted almost to extinction in places. So skates, rays and small sharks are thriving, causing shortages of some of their (and our) favorite foods: oysters and scallops. In fact, according to a new analysis of 35 years of Atlantic wildlife data by researchers at Dalhousie University in Halifax, Canada, and elsewhere, the great shark shortage is to blame for the 2004 closure of North Carolina's century-old bay scallop fishery, among other things.
Bamboo Hunting
Scientists have discovered a new species of bamboo—in the southern Appalachian Mountains. There are 1,400 known species of the woody grass worldwide, but Arundinaria appalachiana is one of only three native to North America. "It's so exciting to find a new species in our own backyard!" says Lynn Clark of Iowa State University. She helped identify the new bamboo, a deciduous species long known to local people as "hill cane."
A Dinosaur's Own Digs
Paleontologists have excavated the first known dinosaur burrow. The 95-million-year-old tunnel, in southwestern Montana, held one adult and two juveniles from a new genus and species: Oryctodromeus cubicularis. The animal apparently had a shovel-like snout and shoulders specialized for digging. The seven-foot-long adult (much of which was tail) probably dug the six-foot-long burrow, which resembles a rodent or hyena den, to protect its young from predators. The find adds to the growing evidence that some dinosaurs were caring parents.
Observed
NAME:Chiroxiphia lanceolata, or the lance-tailed manakin
PROVOCATIVE BEHAVIOR: Males court cooperatively—an alpha male uses an unrelated beta male to attract a female, much as a human male might use a buddy as a "wingman" in a bar. Except manakin males dance with each other. And only the alpha gets to mate.
PROVOCATIVE QUESTION: So what's in it for the other guy?
PROVOCATIVE ANSWER: Three motives have been hypothesized, but only one seems to apply. The beta is neither (a) raising his odds of immediate reproductive success nor (b) helping a blood relative carry on the family line. But a new study from the University of California at Berkeley has found that manakin betas (c) do increase their odds of becoming alphas later, and suggests they are serving an alpha apprenticeship.
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