- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
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...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Snakes' Family Values
17 February 2004 (All day)
Snakes are often thought of as loners. But new findings reveal that sisters of at least one rattlesnake species recognize each other and prefer each other's company over that of strangers. Experts say the discovery is further evidence that snake behavior is more complex than previously suspected.
Despite snakes' reputation as antisocial, there have been a few reports over the decades hinting at social tendencies in these often reclusive and hard-to-observe hunters; for instance, herpetologist Harry Greene of Cornell University and others found in 2002 that maternal care of newborns is widespread in pit vipers.
Cornell University wildlife biologist Rulon Clark had followed radio-tagged adult timber rattlesnakes (Crotalus horridus) in the field for years. He found them far more gregarious than expected; for instance, females often basked together. In a follow-up study in the lab, he raised 24 of these snakes--10 females and 14 males--from three litters. He then housed pairs of snakes together for periods of 3 days in four combinations: sisters, unrelated females, brothers, and unrelated males.
In a paper published online by the Proceedings of the Royal Society Biology Letters on 13 February, Clark reports that when resting coiled, on average, females kept within about 6 centimeters of a sister, but stayed twice as far from unrelated females (~14 cm). (Males, on the other hand, kept at least 20 cm distance from each other, whether they were related or not.) Sisters also touched each other significantly more (~78% of observations) than did unrelated females (~43%).
The findings show that the rattlesnakes can recognize their relatives, despite being raised in isolation from each other for more than 2 years. It suggests the species, and potentially others, "may lead much richer social lives than previously thought," Clark says. Family groupings may protect snakes from predation by safety in numbers as happens elsewhere in the animal kingdom, says Clark, who next plans to see how the rattlers hang out in the wild and how they recognize each other.
Snakes in Australia exhibit "social" behaviors as well, notes evolutionary biologist Rick Shine of the University of Sydney. "It's likely these will prove to be widespread," he says.