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Cliff via Wikimedia Commons // CC BY 2.0
Cliff via Wikimedia Commons // CC BY 2.0

Human-Made Noise May Interfere with Panda Sex

Cliff via Wikimedia Commons // CC BY 2.0
Cliff via Wikimedia Commons // CC BY 2.0

Pandas are not the most motivated animals when it comes to sex. Their apparent disinterest in self-preservation has vexed even the most dogged conservationists for more than 50 years. Why, scientists have asked, won’t they just mate? Researchers think they may have found one reason: noise pollution. They published their findings in the journal Global Ecology and Conservation.

Sound is an essential element of panda sex. Unlike other bears, female pandas are spontaneous ovulators; that is, it happens when it happens, instead of being triggered by an external factor like sex or seasonal changes. But giant pandas are loners, which means it's unlikely that a male panda and a female panda will be in the same place when she starts ovulating. To find each other, they start yelling, and continue to do so even once they’re together. Each outburst could potentially contain a lot of important information about the noise-maker, including their location and their intention—but only if other pandas can hear and understand them.

While we know a lot about bears, we know very little about their hearing. There’s only one species whose hearing abilities have been quantified: polar bears. So conservation biologists at the San Diego Zoo decided to give their five pandas a hearing test.

“… The ability to discriminate between fine-scale differences in vocalizations is important for successful reproduction,” lead author Megan Owen said in a press statement, “and so, a thorough understanding of acoustic ecology is merited in order to estimate the potential for disturbance.”

For obvious reasons, this was a slightly complicated endeavor. First, the researchers had to construct a soundproof testing booth, which in this case meant gluing acoustic foam and plywood onto a transport crate. They outfitted the booth with microphones, speakers, a camera, colored lights, a camera, and a target.

The pandas were somewhat used to taking tests, so it wasn’t difficult for the zoo staff to train them in the booth. The test format played to their natural strength: not moving. The bears were taught to stay still until they heard a noise, at which point they would turn and put their noses against the target.

Once a bear was in the booth, the researchers played a series of noises that pandas might hear in the wild, including cubs crying and squawking and adults growling. As in hearing tests for humans, the sounds varied in pitch and volume.

The researchers found that the pandas had surprisingly sensitive hearing and were able to detect noises between 0.10 and 70.0 kHz—well into ultrasonic range. Their ears were as sharp, and, at some pitches, sharper, than polar bears’.

Wouldn't acute hearing be a good thing for a species that relies on sound to get busy? Yes and no. It’s great if pandas are the only noisemakers around. But as climate change reduces their habitat, even pandas on nature reserves are being pushed closer to people and all of our noisy business. The researchers say anthropogenic, or human-made noise, may drown out the sounds the pandas most need to hear.

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Animals
Where Do Birds Get Their Songs?
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iStock

Birds display some of the most impressive vocal abilities in the animal kingdom. They can be heard across great distances, mimic human speech, and even sing using distinct dialects and syntax. The most complex songs take some practice to learn, but as TED-Ed explains, the urge to sing is woven into songbirds' DNA.

Like humans, baby birds learn to communicate from their parents. Adult zebra finches will even speak in the equivalent of "baby talk" when teaching chicks their songs. After hearing the same expressions repeated so many times and trying them out firsthand, the offspring are able to use the same songs as adults.

But nurture isn't the only factor driving this behavior. Even when they grow up without any parents teaching them how to vocalize, birds will start singing on their own. These innate songs are less refined than the ones that are taught, but when they're passed down through multiple generations and shaped over time, they start to sound similar to the learned songs sung by other members of their species.

This suggests that the drive to sing as well as the specific structures of the songs themselves have been ingrained in the animals' genetic code by evolution. You can watch the full story from TED-Ed below, then head over here for a sample of the diverse songs produced by birds.

[h/t TED-Ed]

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Animals
Watch the First-Ever Footage of a Baby Dumbo Octopus
NOAA, Wikimedia Commons // Public Domain
NOAA, Wikimedia Commons // Public Domain

Dumbo octopuses are named for the elephant-ear-like fins they use to navigate the deep sea, but until recently, when and how they developed those floppy appendages were a mystery. Now, for the first time, researchers have caught a newborn Dumbo octopus on tape. As reported in the journal Current Biology, they discovered that the creatures are equipped with the fins from the moment they hatch.

Study co-author Tim Shank, a researcher at the Woods Hole Oceanographic Institution in Massachusetts, spotted the octopus in 2005. During a research expedition in the North Atlantic, one of the remotely operated vehicles he was working with collected several coral branches with something strange attached to them. It looked like a bunch of sandy-colored golf balls at first, but then he realized it was an egg sac.

He and his fellow researchers eventually classified the hatchling that emerged as a member of the genus Grimpoteuthis. In other words, it was a Dumbo octopus, though they couldn't determine the exact species. But you wouldn't need a biology degree to spot its resemblance to Disney's famous elephant, as you can see in the video below.

The octopus hatched with a set of functional fins that allowed it to swim around and hunt right away, and an MRI scan revealed fully-developed internal organs and a complex nervous system. As the researchers wrote in their study, Dumbo octopuses enter the world as "competent juveniles" ready to jump straight into adult life.

Grimpoteuthis spends its life in the deep ocean, which makes it difficult to study. Scientists hope the newly-reported findings will make it easier to identify Grimpoteuthis eggs and hatchlings for future research.

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