Wild Things: Life as We Know It
Gray seals, alligators and the world’s largest flower
Gray seals have a surprising way to make their air last longer: "deferred food-processing." The marine mammals can stay submerged 20 minutes without coming up for a breath, gulping down as many fish as they can stomach. Most animals start digesting their food as soon as they eat it. But digestion uses oxygen, a precious commodity for an animal holding its breath. Gray seals can put off digestion until after they stop hunting and return to land—sometimes hours later—according to new research from the University of St. Andrews in Scotland. This ability may let seals forage longer and in deeper water.
Orphan Flower Finds Family
The world's largest flower, indigenous to Indonesia, has finally found a home on the tree of life. Reeking of rotting flesh, Rafflesia arnoldii has no leaves, stems or roots—features typically used to classify plants. But a Harvard-led study that analyzed DNA from the flower and its few relatives now says they belong to the family that includes the poinsettia and rubber tree.
Gators in the Gym
Alligators on a treadmill have helped give scientists new insight into how birds fly. The key is a single ligament tying the upper arm to the shoulder joint. In alligators, which are in fact closely related to birds through a common evolutionary ancestor, the ligament isn't prominent, and the reptiles use muscle power to keep their shoulder from dislocating while walking, say researchers at Brown University and Harvard. But in pigeons it's the ligament that holds the shoulder together, freeing up muscle power and enabling the joint to withstand the extreme forces of flight.
The largest study of a tiger population has yielded a rare bit of good news for the highly endangered cats. Researchers working in Nagarahole reserve in southern India, where tigers are relatively safe from poachers, set out camera traps for nine years. They were able to track 74 individual tigers (identified by their stripes). Intriguingly, the overall tiger population grew by 3 percent a year, despite the fact that 23 percent of the tigers died or left the reserve each year. The reason for the growth? Fecundity. Nagarahole's abundance of deer and other ungulates apparently enabled the tigers to breed more readily than expected. Prey is "a key pillar" in tiger conservation, says Ullas Karanth of the Wildlife Conservation Society in Bangalore.
Name:Condylura cristata, or the star-nosed mole, a semiaquatic mammal
native to eastern North America
Hidden Talent: Sniffing under water
Hidden? With that nose?: Yes. That "nose" is actually two nostrils surrounded
by 22 appendages that are supersensitive to touch.
So moles inhale water?: No. Kenneth Catania of Vanderbilt University recently found that, underwater, star-nosed moles exhale air bubbles onto objects and then re-inhale the bubbles. That air carries odorants back through the nostrils, whence they're processed as smells.
Isn't that special: Yes, but not unique. Water shrews can smell this way too.