Posts Tagged ‘animals’
Bats Have Unique Superfast Squeak Muscles to Make Superfast Echolocation Calls
Bats start out with shorter-rate chirps, increasing their frequency as they approach their quarry and culminating in a superfast pulse called the terminal buzz. Watch the video below to see what this sounds like. Coen Elemans and John Ratcliffe at the University of Southern Denmark set out to study how bats produce this buzz. They also wanted to determine whether the upper buzz limit is a function of how quickly the bats can hear the return signals that bounce off their prey, or whether it’s because of the bats’ own call-producing abilities.
They set up a chamber with 12 microphones and recorded the activities of five different free-flying Daubenton’s bats, little bats found in woodland areas from Britain to Japan. The bats hunted mealworms that were suspended in the chamber. The animals’ chirp rate was so rapid that the researchers knew they couldn’t be using normal skeletal muscle.
They attached the bats’ vocal muscles to a motor and a force monitor, and stimulated the muscles to flex. The researchers monitored how long it took a muscle to twitch, and determined the muscles were able to contract and relax at frequencies up to 180 Hz and, in one case, up to 200 Hz.
They also noticed that echoes from individual calls ended before the start of the next call, so the bats don’t confuse themselves. But a bat could theoretically produce calls at a greater frequency than 200 Hz — up to 400 Hz before echo interference would become a problem. The reason they don’t? The superfast muscles are only so fast.
Andrew Mead, a biology graduate student at the University of Pennsylvania’s School of Arts and Science, said the muscle performance could be equated to a car engine: “It can be tuned to be efficient, or tuned to be powerful depending on what you want it to do.”
Bats trade off some force to achieve the rapid oscillations, he said . “In a way it's like an engine that's been tuned for extremely high RPM.”
These laryngeal muscles contract at a rate 20 times that of the fastest human eye muscles, and about 100 times faster than typical skeletal muscles, the researchers say.
Previously, scientists thought these ridiculously quick muscle contractions were only found in the sound-producing organs of rattlesnakes and some types of fish. In 2008, Elemans , too, and now he’s found them in the first mammal. It suggests that these special muscles are more common than previously thought.
The research is published in today’s issue of the journal Science.
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Video: Plucky Fish Swims Far Away to Find Proper Tool For Eating Dinner
The orange-dotted tuskfish, a species of wrasse, is the second type of wrasse documented using tools in the past few months. A blackspot tuskfish was caught on camera earlier this year; now the first video has been .
The fish digs around in the sand to find a choice clam, picks it up, then swims for a while until it finds a good rock. It proceeds to throw the clam against said rock to open it. This is a fish, remember — not the type of creature you might expect to see using tools. , elephants, , sure — but a fish?
“It requires a lot of forward thinking, because there are a number of steps involved. For a fish, it's a pretty big deal,” said , professor of ecology and evolutionary biology at the University of California, Santa Cruz, who shot the video.
The fact that this behavior has been seen in other fish indicates it may not be a , but a deep-seated behavioral trait in wrasses — and maybe other fishes, too.
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A Heated Robotic Mother Hen Improves Quail Chicks’ Spatial Learning Abilities
QuailBot has a space between its wheels where chicks can go get warm
Researchers at the University of Rennes in France built two comfy cube-shaped robotic mother hens, and introduced them to 36-hour-old Japanese quail chicks. The team took 24 chicks and divided them into groups of four. All six groups hung out with the robot for an hour a day for 10 days in a row, according to an . Three groups spent time with a mobilized version of the robot, and three groups got a stationary one. The chicks stopped interacting with the robot after the 10th day.
On the 13th day, the researchers placed the chicks back with their robots and watched what happened. The chicks with the mobile robot mother moved around a lot more, emitting more distress calls. The chicks with the immovable object mother were less active.
On the 14th day, the researchers placed the chicks facing each other, with a grid in the way. The chicks with the mobile mommy navigated around the grid more quickly than the chicks with a stationary HenBot, the researchers said. All this is to show that the chicks with a mobile robot mother had a slight advantage in spatial understanding.
But here’s the rub: This evaporated after a few days. On the 20th day, the team repeated the grid experiment, and found the chicks with the stationary robot had improved so much, there was no longer a significant difference in their behavior.
Still, it’s an interesting example of how robotic technology can impact animal development. Imagine a zoo or a rehabilitation center with some orphaned animals; if they have a movable object the birds can bond with, the birds might do a little better, this study suggests.
The other QuailBot we’ve seen was developed to monitor . It's nice to know this new QuailBot could conceivably help their offspring.
The study was published in the journal Bioinspiration and Biomimetics.
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Scientists Successfully Induce Hibernation in Animals for the First Time
Then they wake them up again
Why is hibernation importnat? Hibernating animals can reduce their metabolism severely, which reduces heart rate and blood flow, enabling them to consume much less oxygen and survive in environments (especially in cold winters) that a non-hibernating animal would not be able to cope with.
These researchers discovered that the molecule that induces hibernation is adenosine, which is produced by all animals, including humans. When adenosine attaches itself to receptors in the brain, it causes the animal to feel sleepy. But in hibernating animals like the arctic ground squirrel, during hibernation season the body produces a huge amount of adenosine, which triggers a much more intense form of sleep--torpor, or hibernation. From that discovery, the scientists created an artificial form of adenosine as well as a synthetic version of caffeine, which was expected to have the opposite effect.
The results were actually a little mixed; the scientists definitely did managed to induce and reverse torpor in the ground squirrels, but that success was partly dependent on the season. During the middle of the hibernation season, torpor was successfully induced in every case, but only a third of the squirrels could be put back into hibernation during the early part of the hibernation season. The scientists are not quite sure yet how the season affects the animal's susceptibility to the drug.
Next up is an attempt with rats, which will give a better sense of how the drug might work on humans. And there are indeed some serious medical uses for induced hibernation: After intense episodes like a heart attack or stroke, many lives could be saved if highly reduced blood flow could be induced. Why else would be looking into it?
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Approved for Use: the First Birth Control for Wildlife
Keeping wildlife baby-free is a hazardous business
An amorous deer is a dangerous deer. While pursued by stags, females often crash into backyards and run into traffic (deer cause about 1.5 million car crashes each year). Insurance claims for deer collisions are three times higher in November, when the animals are usually in heat. Finally, after three decades, a new form of animal birth control has appeared, this time without side effects.
The GonaCon vaccine for whitetailed deer is the first contraceptive approved by the Environmental Protection Agency for use in the wild. After a ranger traps a female, he gives the deer an injection, rendering four out of five females infertile, and thus unattractive to males, for up to five years. When injected, the vaccine, which was developed at the National Wildlife Research Center in Colorado, makes the immune system produce antibodies that bind to gonadatropin-releasing hormones, which inhibits the release of sex pheromones. This May, Maryland became the first state to add GonaCon to its list of approved deer-control devices, alongside bullets and poison.
But trapping animals to administer vaccine injections requires a lot of labor. And in some cases, it’s very dangerous. Take, for example, the four million tusked, up to 400-pound feral hogs that cause more than $400 million in damage to the Texas economy every year by digging up sweet potato fields and rooting where they don’t belong. Feral pigs are intellegent, elusive, and sometimes violent. Duane Kraemer, a professor of veterinary medicine at Texas A&M university, is working on a pig contraceptive delivered out of a feeder. The feeder uses cameras and facial-recognition software to give a dose to pigs and not, say, raccoons. Kraemer says that he hopes to field-test his feeder this fall.
China Makes Clones Of Super-Swine That Survived ’08 Quake
The castrated ‘Strong-Willed Pig’ could not otherwise reproduce
The bacon piglets will probably be sent in pairs to live at a museum and a genetic institute, , which quoted the Hong Kong-based Sunday Morning Post. It’s not clear what will become of them, but perhaps scientists are interested in the genetic traits that helped Zhu survive his ordeal.
Zhu was hailed as a hero after the magnitude 8 earthquake in May 2008, which claimed tens of thousands of human lives and left millions more homeless. The 330-pound hardy hog was trapped beneath rubble for 36 days, but survived by drinking rainwater and chewing charcoal, the AFP reported. He is now 5 years old, which is pretty old for a pig, AFP says — something like 60 in human years.
The pig was castrated pre-quake, so the only way to produce a new generation of super-Zhu was through cloning.
Since Dolly the sheep was cloned in 1996, scientists have been cloning animals for a variety of reasons, including , superior , (really) and even . These little piggies could conceivably serve as a gene bank so scientists can study what made Zhu so tough.
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Amazing Cat Goes Missing in Colorado, Found Five Years Later in New York City, Alive and Well
Found via implanted microchip, she just wanted to try to make it in the big city
It's a hazardous trip, those 1,800 miles, filled with coyotes, foxes, owls, and all kinds of other large animals that prey on cats. We may never know what Willow saw on her journey east, or why she came at all (certainly many New Yorkers would love to make the exact reverse trip, ending up in beautiful Boulder, CO). Maybe she wanted to see The Book of Mormon, or parade her calico self around Fashion Week.
Willow was found on East 20th street, a mere few blocks from PopSci headquarters (home of several avowed cat-lovers) and taken to a shelter run by Animal Care and Control. Luckily, her family, the Squireses of Colorado, implant microchips in all their pets, and ACC was able to scan her chip and locate her family. One of the Squires children was not even born when Willow began her long, strange journey, and only remarked "That's a pretty cat!" when shown a photograph. But her older siblings and her parents all knew Willow immediately, and were understandably stunned.
Even better, the Executive Director of the ACC described Willow as "healthy and well-mannered," noting that she probably had not spent much time hanging around Manhattan. Willow will fly back west in around two weeks, where this adorable story ends in an even more adorable way: "We still have her little Christmas stocking," said Jamie Squires. It may not be as long as the , but we feel pretty comfortable tipping our hats to the best-travelled housecat we've ever seen.
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