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5 December 2013 11:26 am ,
Vol. 342 ,
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Playing the Odds as a Newt
14 January 2000 5:00 pm
A male slithers into a bar looking for a date. He spies a female surrounded by three suitors. What should he do?
Well, if he's a red-spotted newt, he'll back off in a hurry. This common salamander knows when there's too much competition, and three seems to be the magic number. But it's not arithmetic that the newt goes by; rather, he's sniffing an antimale pheromone produced by the competition, Daesik Park of Northern Arizona University in Flagstaff reported last week at the annual meeting of the Society for Integrative and Comparative Biology in Atlanta.
Although some insects are known to emit odors repellent only to males, no such substance in a vertebrate had ever been described, Park says. But his team thought newts might be armed as such because the pond dwellers are known to exude odors for use as long-distant lures and short-distance seducers. Besides, the males need all the help they can get in fathering offspring: They outnumber the females in breeding ponds.
With Northern Arizona reproductive endocrinologist Catherine Propper, Park a graduate student, used a Y-shaped chamber to test whether a male would approach a new newt couple. He found that the lovelorn male is just as likely to go for a female consorting with one or two males in one arm of the Y as he is to choose one on her own in the other arm. But if a female has three suitors, the stag newt will usually opt for the lone female. In other tests, Park found that a male close to a female emits a repelling compound into the water. The more courting males, the more potent the smell--to the point where three stinkpots will put off an aspiring newcomer, Park suggested.
The work "provides us with one more mechanism by which males may compete with other males to enhance their reproductive success," says David Pfennig of the University of North Carolina, Chapel Hill. As Park observed, if a newt decides to hit on a perhaps less desirable but more available female, "the reproductive success of both the pheromone-releasing and -receiving males may be increased."