Science Notebook

Monday, March 16, 2009

THE ANSWER TO A PHILANDERING ANTBIRD

The Encyclopaedia Britannica notes that antbirds -- tropical birds often found in the Amazon chasing columns of swarming ants -- "have loud, usually unmusical voices that may be heard in echo duets."

Research to be published in the journal Current Biology in April suggests a possible explanation for the cacophonous duets: Female antbirds, researchers have found, "jam" the calls of their mates to other females by singing over the male voices. In response to being jammed, the males then change their tune.

Researchers Joseph A. Tobias and Nathalie Seddon of the University of Oxford said this was the first example of behavior involving jamming, and jamming avoidance, ever seen in nature.

"In human terms, signal jamming is most commonly associated with attempts to scramble information in radio, radar, or cell phone signals," Tobias said in a statement. "The females in our study try to do a similar thing with the songs of their partner, but the overall situation is more analogous to a wife continually interrupting her husband to stop him from flirting with a single woman."

Bird duets, the researchers conclude, can tell complex stories about conflict and cooperation within a species. By recording the birds and playing back their duets, the researchers found that there were times when male and female birds would sing in harmony -- often when they were fending off common rivals. But when the bond between the birds was threatened by a single female, the birds resorted to cacophonous jamming and jamming defense calls.

If such techniques were part of the evolutionary history of humans, the researchers noted, "our results may help to explain the first steps towards complex, coordinated group signals in humans, which themselves are the likely forerunners to modern music."

-- Shankar Vedantam

AN UNTANGLED TALE

A team of scientists was able to sedate a large, free-swimming whale for the first time this month, allowing the disentangling of hundreds of feet of rope that was impeding the animal from migrating.

The seven-year-old endangered North Atlantic right whale, known to National Oceanic and Atmospheric Administration researchers as #3311 or "Bridle," was first spotted in trouble Jan. 14. Experts made four attempts to rescue it over the next month and a half. But it was only after a team from NOAA Fisheries and the Woods Hole Oceanographic Institute successfully sedated the whale March 6 that scientists were able to pull off a significant amount of rope.

Jamison Smith, NOAA Fisheries large whale disentanglement coordinator, managed to shoot two separate darts containing the equivalent of two cups of sedative into the animal's back end from a boat more than 50 feet away. After an hour and 15 minutes, scientists were able to approach the whale, which had been evasive before.

Smith said the whale did not stop swimming or breathing as a result of the sedative, which pierced its blubber and entered its muscle. "It just didn't care that we were right next to it," he said, adding that rescuers pulled off 90 percent of the rope entangling the animal over the course of multiple attempts. "As soon as we pulled the rope off it, you could tell it really picked up speed."

A record number of right whales -- five -- have become entangled in fishing gear off the East Coast this calving season, but a coalition of federal and state officials, working in concert with private researchers, have been able to free four of them.

-- Juliet Eilperin

THE HOLY GRAIL OF PHYSICS

Scientists at the Fermi National Accelerator Laboratory, the atom smasher in Batavia, Ill., are touting a milestone in the search for what has been called the Holy Grail of physics, the Higgs boson.

After many years of smashing together protons and anti-protons and searching through the subatomic wreckage, the scientists say they've been able to reduce the range of possible masses of the theoretical Higgs. They are hoping that their collider, the Tevatron, may yet tweeze a Higgs from the flotsam of atomic debris before the Large Hadron Collider, the Europeans' new, balky collider near Geneva, manages to find it.

"It is possible we will see good evidence for the Higgs before the LHC has enough data to do the same," said Jacobo Konigsberg, a University of Florida physicist working at Fermilab.

No one has ever seen a Higgs. It exists only in theory, the logical product of the Standard Model of particle physics. The Higgs, in theory, is what gives other particles the property of mass. If the theory is correct, Higgs particles have likely been produced in Tevatron collisions, but they remain hard to discern in the general spray of particles in the detector.

The LHC, housed in an 16.74-mile-long tunnel, is still being repaired after an explosion in September, shortly after engineers turned it on. That collider, operated by the European consortium known as CERN, is many months from operation and many more months from producing scientific results. But the more modest Tevatron has been running for nearly a decade, and the Fermilab physicists say its best work may yet lie ahead.

The new result identifies a range of mass in which the Higgs is clearly absent. Konigsberg uses a fishing analogy: "If you fish in a certain region, you're not going to find the Higgs. We've fished enough to know that it cannot be there. So now we have to move to another part of the lake."

There is one other possibility: The Higgs hasn't been found because -- defying conventional wisdom and the dictates of the Standard Model -- it doesn't exist, anywhere, ever.

-- Joel Achenbach