Cary

Here’s a memorable encounter between David Attenborough and a three-toed sloth, as shown in Life of Mammals. Sloths normally spend their lives hanging from high branches, but this one ambles down to the ground at the 1:10 mark. “It wants to defecate,” says Attenborough, “and the only place it’s happy doing that, oddly enough, is down on the ground.”

This happens once a week. The sloth climbs down, digs a small bowl in the ground with its tail, and poos.  It covers up its latrine with leaves before climbing back up.

This behaviour is bizarre. Sloths not only burn 8 percent of their daily calories on these laborious descents and climbs, but they are incredibly easy prey on the ground. Look at the video—Attenborough only has to slowly lean forward to scrag the animal. In fact, more than half of all sloth deaths are due to predators killing them while travelling to and fro their low latrines. If a sloth s**ts in the woods, predators seem to know.

So why do it? Surely, there must be some advantage. Otherwise, why waste energy and risk death, when they could just defecate from high branches and let gravity carry their poo away? Some people think that the sloths are fertilising their favourite trees, while others have suggested that they communicate with other sloths using the latrines.

But Jonathan Pauli from the University of Wisconsin-Madison has a different explanation. It involves thinking of a sloth as less of an individual, and more of a mobile ecosystem.

In their fur, sloths host a diverse community of fungi, algae, insects, mites and ticks. (In one case, scientists found 980 beetles in the fur of a single animal). Many of these residents are found nowhere else. To them, the sloth is the only world they know. The three-toed sloth even has adaptations that help it cultivate these partners. For example, its hair contains cracks that collect rainwater, and acts as miniature hydroponic gardens for growing algae.

The fur also contains moths. Cryptoses moths live exclusively on sloths, probably feeding on their skin secretions or algae. There can be up to 120 of them in one individual.

The moths are entirely dependent on the sloths, and specifically on their daring defecation descents. While the sloths do their thing, the female moths fly off and lay eggs in the fresh dung. The larvae eat nothing else. Surrounded by a banquet of delectable sloth faeces, they slowly transform into adults, before flying into the canopy and colonising more sloths. Beautiful.

So Pauli wondered: do the sloths also depend on the moths? Is that why they risk the dangers of terra firma, even though a squatting sloth is a sitting duck?

To find out, his team compared two types of sloth in Costa Rica—the brown-throated three-toed sloth, which always defecates on the ground, and Hoffmann’s two-toed sloth, which only sometimes does so. They cut locks of hair from the animals, sucked up all the moths using an “invertebrate vacuum”, and analysed the chemical composition of the remaining fur and algae.

They found that the number of moths, the amount of algae, and the nitrogen content of the fur were all connected. If an individual has more moths, it also has more algae and more nitrogen. And three-toed sloths have more of all the above than the two-toeds.

Pauli believes that the moths seed the sloth’s fur with nutrients that spur the growth of the algae. Maybe they’re transporting nitrogen-rich waste from the dung pile into the fur. Maybe they die in the fur and release nitrogen when they’re decomposed by fungi. Either way, they seem to fertilise the algae.

This matters because, according to Pauli, the algae are an important food source for the sloths. His team mixed the sloth fur with bacteria from a cow’s stomach and showed that the algae within can be easily digested. They also analysed the chemical make-up of the algae and found that it has as much carbohydrate and protein as the leaves that the sloths normally eat, but three to five times more fat. (It’s possible that the algae, by painting the sloths green, help to camouflage them from predators like harpy eagles.)

So, the moths help to fertilise the sloths’ algal gardens, which gives the sloths a valuable energy boost to supplement their otherwise poor diets. The sloths, in turn, defecate on the ground to help their partners-in-gardening to complete their life cycle. They may die, but that’s a risk they have to take. They are locked into this partnership.

This would explain why the three-toed sloth always defecates on the ground while its two-toed cousin will often do it from the trees. The two-toed forages on a wider range of food so, as Pauli found, it isn’t so reliant on the moths or the algae.

But there are still a few loose threads. For example, the team haven’t calculated how much energy the algae could hypothetically provide, and whether that makes up for the cost of travelling to the ground once a week.

And Brazilian researcher Adriano Chiarello points out an even bigger problem with the hypothesis. He and his students have spent more than 1,000 hours watching maned sloths in the wild. “We never saw sloths behaving in a way that might suggest or indicate that they were somehow extracting algae or other nutrients from their fur,” he says. They’re not like cats; they clean their fur with their front paws rather than their mouths. “I don’t remember ever seeing a sloth licking or lapping its fur.”

So, how exactly are they eating the supposedly nutritious algae? “Perhaps sloths do this secretly, or solely at night when such behaviour would be even more difficult to witness,” says Chiarello. Or, perhaps they’re absorbing the nutrients directly through their skin. He’s not convinced by either possibility and, either way, “the smoking gun is missing”.

Still, Chiarello says the study is a strong piece of work. “Testing hypothesis with sloths is not easy as they are difficult to capture and observe in their natural environment,” he says. “The authors are making their best with available data.” He hopes that more will come.

Reference: Pauli, Mendoza, Steffan, Carey, Weimer & Peery. 2014. A syndrome of mutualism reinforces the lifestyle of a sloth. Proc Roy Soc B http://dx.doi.org/10.1098/rspb.2013.3006

More on sloths: Portable brain activity-recorder shows that sloths aren’t all that sleepy

What if I told you, you can have creme brûlée at any time of the day and nobody would ever question you about your dessert obsession? These four bloggers get it –– they've managed to sneak that creme brûlée taste into unassuming recipes like French toast and oatmeal.

READ MORE »

"Don’t Judge Me… This Is Art!"

For only $770.01, you not only get a swinging outdoor bed, but an insane run-on-sentence title. (Check out the actual name of the product, for real.)

humansofnewyork:

"What’s your favorite thing about each other?"
"His honesty."
"Her hashbrowns."

Short height and long life have a direct connection in Japanese men, according to new research. Shorter men are more likely to have a protective form of the longevity gene, FOXO3, leading to smaller body size during early development and a longer lifespan. Shorter men are also more likely to have lower blood insulin levels and less cancer.

The Ivanpah Solar Power Facility is a very large solar thermal power facility.  And by “very large,” I mean very large.  In fact, it is so enormous it’s hard to even wrap your mind around how large it is.   It also cost about 2.2 billion dollars, which is quite a lot of money.   A reasonably sized nuclear power plant could be built for the same cost.  In the US, this would be difficult, given the regulatory costs, but other countries have built modern Generation III+ reactors for two billion dollars per unit or less.

 

Of course, that’s just the capital cost.  It’s harder to pin down the operational cost.  As many will point out, it doesn’t use any fuel in the conventional sense.  But it does employ 86 full time workers, plus an even larger number of contractors.  It also has a lot of sensitive equipment baking in the sun, which is likely to need frequent replacement.   It’s hard to know exactly what it costs to operate the plant and what the cost per kilowatt hour comes out to be, because the operators have kept much of the relevant financial data confidential.

What is known is that the agreed price per wholesale kilowatt hour is “at or below” 12.5 cents per kwh, before time and demand adjustments.  That would seem to imply it is more expensive than other methods of power generation.   Published data indicates the cost of operating a solar thermal power plant is more than 2.5 times that of a coal or nuclear facility.  The Ivanpah facility may benefit from economics of scale to bring that down a bit, but it’s still clear that the plant has a much higher cost per megawatt-hour than a fossil fuel power station.

None the less, plants like Ivanpah are financially viable, at least for the time being.  They receive massive tax credits and other

But in terms of power output, it’s not actually that big…

The total nameplate capacity of the Ivanpah facility is anticipated to be 377 megawatts, when complete.  That’s not small, but it’s not really that large either.  In utility terms, if it were a standard thermal power plant, it would be considered medium sized.  By comparison, a modern nuclear facility with two generation III+ reactors might have an output of between 2.5 and 3.5 gigawatts.  Large coal and gas plants can be equally large and occasionally larger.

377 megawatts, however, would be enough to power the New York City subway system, but not during rush hour.  It would power a medium sized aluminum smelter.  It would not be enough to power a city of any size, but could provide the power used by a medium sized town on a summer day.

Of course, 377 MW is the anticipated nameplate capacity of the plant.  The capacity factor is only about 30%, meaning that the plant could be thought of as the equivalent of a continuously operating base-load power plant that produces about 110-120 megawatts.  Most nuclear and coal plants operate at near full capacity most of the time.  There are also many hydroelectric plants that crank out a continuous 120 megawatts night and day.

In utility terms, that’s hardly a lot of power.  It’s more than enough to power everything in many homes, but a power plant with this capacity would not be considered very large at all. It’s more in line with the kind of “distributed” power plants that might be used to provide local peaking and load-following.  It’s less power than a large ship produces.  Even a single 747 can produce more power when cruising.  It is, however, enough to power a few dozen small to medium sized locomotives.

So it is not tiny but not that big, and comes at a huge financial cost.

But there is another cost, not as obvious but a bit more dramatic:

The Ivanpah Solar Power Facility has killed quite a few birds.   Other things kill birds too, of course.  Wind turbines are notorious for killing birds.  Birds also fly into radio towers and they strike large glass paned windows.  But the the Ivanpah facility kills birds in a uniquely dramatic, even disturbing way.

Via Desert Sun:

Birds going up in smoke at Ivanpah solar project

A new report from the U.S. Fish and Wildlife Service has labeled BrightSource Energy’s Ivanpah project a “mega-trap” for insects and birds that may get singed or in some cases, burned alive flying through the intense solar radiation reflecting off the thousands of mirrors surrounding three solar towers at the plant in eastern San Bernardino County.

The Center for Biological Diversity posted the report to the California Energy Commission website on Monday as part of its testimony opposing BrightSource’s 500-megawatt Palen project, located east of the Coachella Valley, which would use similar technology — soaring solar towers surrounded by thousands of reflecting mirrors.

Read the report

“Although not analyzed in detail, there was also significant bat and insect mortality at the Ivanpah site, including monarch butterflies,” the report said. “It appears that Ivanpah may act as a ‘mega-trap,’ (original emphasis) attracting insect-eating birds, which are incapacitated by solar flux injury, thus attracting predators and creating an entire food chain vulnerable to injury and death.”

Solar flux is the intense radiation coming off the reflecting mirrors. At Ivanpah, the radiation is so intense it creates what look like small clouds around the boilers at the top of the project’s three 459-foot-tall solar towers. These clouds appear to be attracting the insects which in turn attract the birds.

….

“Ivanpah employees and OLE staff noticed that close to the periphery of the tower and within the reflected solar field area, streams of smoke arise when an object crosses the solar flux fields aimed at the tower. Ivanpah employees use the term ‘streamers’ to characterize this occurrence.

“When OLE staff visited the Ivanpah Solar plant, we observed many streamer events. It is claimed that these events represent the combustion of loose debris, or insects. Although some of the events are likely that, there were instances in which the amount of smoke produced by the ignition could only be explained by a larger flammable biomass such as a bird. Indeed, OLE staff observed birds entering the solar flux and igniting, consequently becoming a streamer.

“OLE staff observed an average of one streamer event every two minutes. It appeared that the streamer events occurred more frequently within the ‘cloud’ area adjacent to the tower. Therefore we hypothesize that the ‘cloud’ has a very high temperature that is igniting all material that traverses its field.”

The birds really don’t seem to stand a chance. The intensity of the concentrated beam of light is so great that they actually burst into flames as soon as they enter it. It’s reported to be a very dramatic (and frequent) site.

Exactly how many birds have been killed by the facility is more difficult to determine than it might seem. The report from the Fish and Wildlife Service cited 71 charred bird carcasses found on site. It is, however, a very large area, and it’s certainly not unreasonable to suppose many were not found, especially if they were severely burned and decomposed. It has also been observed that not all birds are killed by the beams. Some may enter in an area of lower flux or at a time of day when the sun is not as intense. In these cases, the birds would be severely injured, but not incinerated, and could leave the area before dying of the injuries.

So while it is currently difficult to give any solid numbers, what can be said is that this does not appear to be an uncommon event. In fact, based on what workers have been seeing, it happens many times per day.

It is just another example of a “green and environmentally friendly” power generating technology having an embarrassing flaw.

On whether the bird deaths are “worth it:”

Whether or not burning a few birds is a worthwhile sacrifice is a complex question.  Nearly all human development has some environmental costs.  Thermal power plants routinely kill fish larva and birds lose their lives as a result of skyscrapers, antenna masts and large glass curtain windows.

The Ivanpah Solar Plant has other impacts to the local environment.  Its construction led to a loss of habitat for a number of threatened or endangered species, most notably the desert tortoise.  It also is a major consumer of local water resources, despite using a cooling system that is primarily air-based and thus uses less water than alternative cooling methods.  This also does not include the total environmental impact of things like replacement parts, energy expended in transporting workers to work and the cost of eventually decommissioning the plant.   At present, there is little good data on the full life-cycle impacts of the plant.

At least in my opinion, the death of some birds might well be a worthy sacrifice IF the plant actually generated very large amounts of reliable energy and did so with good economics.  It doesn’t.  Thus, any added costs simply makes an already bad deal even worse.   So while nuclear plants may kill plankton and fish larva and hydroelectric facilities impact fish and aquatic life, those impacts are generally a small price to pay for the energy produced.  Here, you are getting much less than what you pay for.

Hey chickadees, want something to do while I’m off doing that “being social” and “getting married” thing? I mean, besides giving me a wedding gift of cat surgery money? ;P

Learn some chem with Compound Interest! Okay, I know it’s a painful subject. In fact, organic chem is why I gave up my initial desire to become a veterinarian. But despite the pain, it’s fascinating. And Compound Interest is a master at accurate, catchy infographics, helpful study advice, and chemistry lessons from the most unexpected places.

They’re also proponents of stopping bad science, and stopping bad reporting of good science, so they’re ace in my books. 

Compound Interest on Tumblr

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Official Compound Interest Infographics

Seriously guys, I cannot express my level of new-found fascination with chemistry thanks to these guys. I’d forgotten how cool it was and how much I really loved the chemistry of microbiology, even when I didn’t always understand it.

Compound Interest: Officially loved by Biomedical Ephemera! :D

A Georgia Republican candidate said he would rather see another terrorist attack than submit to the “jack boot” thugs in the Transportation Security Administration.

Bob Johnson, a Savannah surgeon running in the First Congressional District GOP primary, made the remarks during a February campaign appearance, but video of the event was first reported Tuesday by Politico.

“The TSA is doing something really profound — they’re indoctrinating generations of Americans to walk through a line and be prodded and probed by uniformed personnel, agents of the government, like sheep,” Johnson said during a campaign forum in Waycross.

“Now this is going to sound outrageous,” Johnson continued. “I’d rather see another terrorist attack — truly I would — than to give up my liberty as an American citizen. Give me liberty or give me death. Isn’t that what Patrick Henry said at the founding of our Republican — or, republic?”

Sources told the Atlanta Journal-Constitution that all the other Republican candidates were present at the event.

“People are saying, ‘Now everyone wants security before anything else. I want a perfectly safe flight,’” Johnson said. “You’re not going to have it. We’re going to have jack-boot uniformed people in our backyards.”

State Rep. Jeff Chapman of Brunswick and physician Earl Martin of Blackshear can be in the video flanking Johnson, but they did not visibly react to his remarks.

State Sen. Buddy Carter is considered the frontrunner, the newspaper reported, with Johnson and businessman John McCallum his most likely runoff opponents in the solidly conservative district.

Farmer Darwin Carter is also among the candidates vying to replace Rep. Jack Kingston (R-GA), who is running for the U.S. Senate.

A spokesperson for Johnson said Tuesday that the candidate described his remarks as “stupid,” but he repeated his criticism of the TSA.

“As a 26-year Army Ranger, head and neck surgeon and even a Christian medical missionary, I’ve sworn my life to defending this country and keeping people safe,” Johnson said in a statement. “And as a Constitutional conservative, it angers me that we are giving up our liberty to the bureaucratic TSA and spying on our own people in the name of false security and that has to stop.”

“I’m very passionate about the ideals of liberty, freedom and maintaining a strong national defense, and these conservative ideals shouldn’t be at odds with each other,” Johnson added. “In the heat of the moment, while making the point that I would much rather fight the enemy than our federal government, I said something stupid and should have chosen my words more carefully.”

Watch video of Johnson’s remarks posted online by Aymon Laforge:

[Image via Facebook]

Oregon-based artist Jennifer Delaurenti has always created her amazing selection of sketches as a hobby. However, Reddit user delpaint believed that the work deserved more than just sitting around the house. So he posted his mother's work online and it has quickly become quite the hit. Upon first glance, viewers might believe that the image is all one piece. However, the truth is that each piece is a blend of photograph and sketch.

Delaurenti uses old photographs as the foundation for her work. She places a single image in the center of a composition and then extends the scene beyond the edges of the images by hand drawing the background. She uses a deliberately selected color palette of colored pencils to match the original, and the details of her drawings appear to perfectly match the rest of the documented moment.

Although Delaurenti used to only create the pieces for friends, in just days, the hobby has turned into a business. Original and commissioned pieces can be ordered online through Delaurenti's Etsy Shop.

Jennifer Delaurenti's Etsy Shop
via [Viral Nova]

One afternoon, my coworker Lisa Guy and I are looking through her photo archive, when I spy something that looks like an purple butterball turkey being attacked by a lime green scrunchie. Of course I have to find out what it is. When I ask, Lisa pulls up the photo and says “It’s a baby cormorant […]

zagreus-taking-time-apart:

steampoweredsass:

zagreus-taking-time-apart:

We teach kids to fear animals like rats, snakes, spiders, etc. that are harmless 99% of the time but do we ever warn them about the real danger

WHY DOES IT HAVE TEETH ON ITS TONGUE

I am a gooseologist and I can tell you that geese live on a healthy diet of children’s souls which can only be properly chewed with unholy tongue teeth

noodleweight:

catsgomeowalot:

my new favorite gum

what the fuck.

Buster Keaton and Kathryn McGuire ad nauseam (watch the original scene)

This pack of 1,600 papier-mâché pandas might look adorable, but they come bearing a more serious message. In real life, the species is in rapid decline due to loss of their ecosystem by human development. French artist Paulo Grangeon worked with the World Wildlife Fund (WWF), PMQ, and creative studio AllRightsReserved to craft this bevy of pandas that alerts the public on the tragic truth of these animals.

Each sculpture is made from recycled paper and represents a single member of the species that’s still alive today. It’s a bit shocking to look at this gathering and realize that this is all of the pandas that are left in the wild. The hope is that this large and impressive public project will spread awareness of this environmental crisis.

The pandas are currently on tour in Hong Kong and have already traveled to cities like Paris, Rome, Berlin, and Taipei. They will stop at 10 landmarks, including the Hong Kong International Airport and the giant Tian Tan Buddha beginning this June. Grangeon will also create four special-edition paper pandas, which will go on display at PMQ in support of conservation and to promote the message of a coexistence between humans and nature.

Paulo Grangeon papier-mâché page
via [designboom]

Big ol’ sexy thanks to my buddy, Jason for helping me work out this joke. Read his coooommmiiiiics!

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When Bill Moyers asked surveillance expert and author Heidi Boghosian if she considered Edward Snowden a “troublemaker” along the lines of the Occupy Wall Street movement, Boghosian went beyond that term in endorsing his revelations concerning the National Security Agency’s global data mining.

The former NSA contractor, she said on Moyers & Company, is “a troublemaker, and a true hero and patriot,” arguing that “working as he did for a private corporation, handling sensitive information, and being told basically that there was no problem, there was nothing he could do, he then took matters into his own hands, knowing that he would probably face imprisonment for the rest of his life.”

Though Snowden’s request for clemency from the U.S. has been rejected, Boghosian credited him with waking the American public up to the widespread nature of the NSA’s monitoring activities through his series of leaks to the British newspaper The Guardian.

“So it’s not a matter of your saying, as so many people are, ‘What if I’m not doing anything wrong, why should I care if anybody’s watching?’” Moyers asked her. “You’ve heard that, haven’t you?”

“I think that’s a very simplistic answer,” Boghosian replied. “Because when one is under constant surveillance, be it from a surveillance camera on the city block and we have so many here in New York, to the possibility that internet communications are being monitored, it necessarily alters how you communicate. It makes us tamp down things that we might say.”

Moyers also mentioned a New York Times report about the Central Intelligence Agency paying more than $10 million a year to AT&T to open their phone records up, a type of alliance Boghosian linked to the rise of consumerism in American society, as people are lulled into trusting corporations with more of their personal data.

“They are hand-in-hand working to gather information about Americans as well as people across the globe, to really be in a race to collect more information than any other country can,” she explained to Moyers. “I think in their eyes, having this information, storing it, and being able to access it for years on end is a symbol of power and control. So that you can’t really make that distinction anymore between big business and government.”

Watch Moyers’ interview with Boghosian, as released on Friday, below.