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In one of the tallest trees on Earth, a tan, mottled salamander ventures out on a fern growing high up on the trunk. Reaching the edge, the amphibian leaps, like a skydiver exiting a plane.

The salamander’s confidence, it seems, is well-earned. The bold amphibians can expertly control their descent, gliding while maintaining a skydiver’s spread-out posture, researchers report May 23 in Current Biology.

Wandering salamanders (Aneides vagrans) are native to a strip of forest in far northwestern California. They routinely climb into the canopies of coast redwoods (Sequoia sempervirens). There — as high as 88 meters up — the amphibians inhabit mats of ferns that grow in a suspended, miniature ecosystem. Unlike many salamanders that typically spend their days in streams or bogs, some of these wanderers may spend their whole lives in the trees.
Integrative biologist Christian Brown was studying these canopy crawlers as a graduate student at California State Polytechnic University, Humboldt in Arcata, when he noticed they would jump from a hand or branch when perturbed.

Now at the University of South Florida in Tampa, Brown and his colleagues wondered if the salamanders’ arboreal ways and proclivity to leap were related, and if the small creatures could orient themselves during a fall.

Brown and his team captured five each of A. vagrans, a slightly less arboreal species (A. lugubris), and two ground-dwelling salamanders (A. flavipunctatus and Ensatina eschscholtzii). The researchers then put each salamander in a vertical wind tunnel to simulate falling from a tree, filming the animals’ movements with a high-speed camera.

In all of 45 trials, the wandering salamanders showed tight control, using their outstretched limbs and tail to maintain a stable position in the air and continually adjusting as they sailed. All these salamanders slowed their descents’ speed, what the researchers call parachuting, using their appendages at some point, and many would change course and move horizontally, or glide.

“We expected that maybe [the salamanders] could keep themselves upright. However, we never expected to observe parachuting or gliding,” Brown says. “They were able to slow themselves down and change directions.”
A. lugubris had similar aerial dexterity to A. vagrans but glided less (36 percent of the trials versus 58 percent). The two ground huggers mostly flailed ineffectively in the wind.

The wandering salamanders’ maneuverable gliding is probably invaluable in the tops of the tall redwoods, Brown says. Rerouting midair to a fern mat or branch during an accidental fall would save the effort spent crawling back up a tree. Gliding might also make jumping to escape a hungry owl or carnivorous mammal a feasible option.

Brown suspects that the salamanders may also use gliding to access better patches to live. “Maybe your fern mat’s drying out, maybe there’s no bugs. Maybe there are no mates in your fern mat, you look down — there’s another fern mat,” Brown says. “Why would you take the time to walk down the tree and waste energy, be exposed and [risk] being preyed upon, when you could take the gravity elevator?”

There are other arboreal salamanders in the tropics, but those don’t live nearly as high as A. vagrans, says Erica Baken, a macroevolutionary biologist at Chatham University in Pittsburgh who was not involved with the research.

“It would be interesting to find out if there is a height at which [gliding] evolves,” she says.

A. vagrans’ relatively flat body, long legs and big feet may allow more control in the air. Brown and his colleagues are now using computer simulations to test how body proportions could impact gliding.

Such body tweaks, if they do turn out to be meaningful, wouldn’t be as conspicuous as the sprawling, membraned forms seen in other animals like flying snakes and colugos that are known for their gliding (SN: 6/29/20; SN: 11/20/20). There may be many tree-dwelling animals with conventional body plans that have been overlooked as gliders, Brown says. “The canopy world is just starting to unfold.”

Four billion years ago, lava spilled onto the moon’s crust, etching the man in the moon we see today. But the volcanoes may have also left a much colder legacy: ice.

Two billion years of volcanic eruptions on the moon may have led to the creation of many short-lived atmospheres, which contained water vapor, a new study suggests. That vapor could have been transported through the atmosphere before settling as ice at the poles, researchers report in the May Planetary Science Journal.
Since the existence of lunar ice was confirmed in 2009, scientists have debated the possible origins of water on the moon, which include asteroids, comets or electrically charged atoms carried by the solar wind (SN: 11/13/09). Or, possibly, the water originated on the moon itself, as vapor belched by the rash of volcanic eruptions from 4 billion to 2 billion years ago.

“It’s a really interesting question how those volatiles [such as water] got there,” says Andrew Wilcoski, a planetary scientist at the University of Colorado Boulder. “We still don’t really have a good handle on how much are there and where exactly they are.”

Wilcoski and his colleagues decided to start by tackling volcanism’s viability as a lunar ice source. During the heyday of lunar volcanism, eruptions happened about once every 22,000 years. Assuming that H2O constituted about a third of volcano-spit gasses — based on samples of ancient lunar magma — the researchers calculate that the eruptions released upward of 20 quadrillion kilograms of water vapor in total, or the volume of approximately 25 Lake Superiors.

Some of this vapor would have been lost to space, as sunlight broke down water molecules or the solar wind blew the molecules off the moon. But at the frigid poles, some could have stuck to the surface as ice.

For that to happen, though, the rate at which the water vapor condensed into ice would have needed to surpass the rate at which the vapor escaped the moon. The team used a computer simulation to calculate and compare these rates. The simulation accounted for factors such as surface temperature, gas pressure and the loss of some vapor to mere frost.

About 40 percent of the total erupted water vapor could have accumulated as ice, with most of that ice at the poles, the team found. Over billions of years, some of that ice would have converted back to vapor and escaped to space. The team’s simulation predicts the amount and distribution of ice that remains. And it’s no small amount: Deposits could reach hundreds of meters at their thickest point, with the south pole being about twice as icy as the north pole.

The results align with a long-standing assumption that ice dominates at the poles because it gets stuck in cold traps that are so cold that ice will stay frozen for billions of years.
“There are some places at the lunar poles that are as cold as Pluto,” says planetary scientist Margaret Landis of the University of Colorado Boulder.

Volcanically sourced water vapor traveling to the poles, though, probably depends on the presence of an atmosphere, say Landis, Wilcoski and their colleague Paul Hayne, also a planetary scientist at the University of Colorado Boulder. An atmospheric transit system would have allowed water molecules to travel around the moon while also making it more difficult for them to flee into space. Each eruption triggered a new atmosphere, the new calculations indicate, which then lingered for about 2,500 years before disappearing until the next eruption some 20,000 years later.

This part of the story is most captivating to Parvathy Prem, a planetary scientist at Johns Hopkins Applied Physics Laboratory in Laurel, Md., who wasn’t involved in the research. “It’s a really interesting act of imagination.… How do you create atmospheres from scratch? And why do they sometimes go away?” she says. “The polar ices are one way to find out.”

If lunar ice was belched out of volcanoes as water vapor, the ice may retain a memory of that long-ago time. Sulfur in the polar ice, for example, would indicate that it came from a volcano as opposed to, say, an asteroid. Future moon missions plan to drill for ice cores that could confirm the ice’s origin.

Looking for sulfur will be important when thinking about lunar resources. These water reserves could someday be harvested by astronauts for water or rocket fuel, the researchers say. But if all the lunar water is contaminated with sulfur, Landis says, “that’s a pretty critical thing to know if you plan on bringing a straw with you to the moon.”

The pandemic has entered a murky stage, and social norms are quickly shifting, something I’ve thought a lot about lately. Many people are testing at home, or not at all. Here in Vermont, where I live, you can pick up a type of PCR test that can be taken at home. But state officials both here and elsewhere are no longer carefully monitoring the results of these tests, which means that the actual spread of coronavirus in the U.S. population remains unclear (SN: 4/22/22).

For a few weeks, rumors of a stealth COVID-19 wave have been circulating both in the media and on my Twitter feed. Now cases and hospitalizations are rising, as are the levels of coronavirus in wastewater. That suggests that more cases, and ultimately deaths, could follow.
Even with rising caseloads and a vaccination rate that has flatlined at about 66 percent of the eligible population, the American public has largely begun to move on from the COVID-19 crisis. People are shedding their masks, eating out, attending concerts, traveling to far-flung locations, having large, indoor weddings and doing all the social things that people tend to do when left to their own devices.

The 2,600-person White House Correspondents’ Association dinner late last month is a case in point. Just as host Trevor Noah prophesied, many of those in attendance have since tested positive for COVID-19, including U.S. Secretary of State Antony Blinken and reporters from NBC, ABC, the Washington Post, Politico and other media outlets. And those who almost certainly knew better — cue White House Coronavirus Response Coordinator Ashish Jha — nonetheless made an appearance.

Myriad quirks related to human behavior undoubtedly underpin these arguably poor choices. The Decision Lab website has a list of the biases and mental shortcuts people use to make decisions. The one that caught my eye is social norms. This particular quirk outlines what behaviors people deem appropriate in a given situation.

I started thinking about social norms while writing a feature on how to get people in the United States to eat less meat when the practice is so, well, normal (SN: 5/11/22). Social norms, my research informed me, vary with the group one is hanging out with and one’s environs. “We rapidly switch our perspective depending on the context of the situation we find ourselves in,” writes marketing expert John Laurence on the Decision Lab site.

I might have found this idea of rapid switching suspect had I not recently experienced the phenomenon. My husband’s Disney-phile brother and his wife had been planning a family reunion in Disney World in Florida since the start of the pandemic. And I, a curmudgeonly sort not prone to feeling the magic, long ago agreed to go on the condition that other people do all the planning. And so it was, after multiple COVID-related postponements, that my kids, my husband and I landed in Orlando on a blisteringly hot April day.

Disney normal, I soon learned, bore little resemblance to Vermont normal. This was obvious immediately from people’s attire. All around me parents and kids dressed in coordinated outfits and matching Mickey Mouse ears. (Apologies to my kids — your mom missed the fashion memo.)
Social norms almost certainly arose to foster cohesion among our earliest ancestors, who needed solidarity to hunt large prey, share limited resources and ward off predators and enemy tribes. In-group norms also provide humans with a sense of belonging, which research suggests is vital for our overall health. A meta-analysis of more than 3.4 million people followed for an average of seven years showed that the likelihood of dying during the study period increased by 26 percent for participants who reported feeling alone (SN: 3/29/20).

Not surprisingly, then, one of the strongest drivers of human behavior is to seek out belonging. At Disney, that quest means blocking out the reality that exists just outside the fiefdom. Wars, climate crises, political fighting and the like have no place within those magical walls. Nor do reminders of a global health crisis that, according to the latest World Health Organization estimates, has thus far killed nearly 15 million people worldwide.

Within Disney’s walls, throngs of mostly maskless tourists packed onto iconic rides and into restaurants. When halfway through our trip, a Florida judge ruled that masks could not be mandated on public transit, nary a mask was to be seen on buses shuttling people to the Magic Kingdom and Epcot Center. And everywhere, all the time, people seemed to be coughing, sniffling or blowing their noses.

As a science reporter covering COVID-19, I certainly knew that I should keep my mask on. And yet, my resolve soon faltered. My kids pointed out that no one else was masking, not even my typically rule-following relatives. Donning my mask meant confessing that I was not reveling in the sparkle and glitz and magic and making all too obvious to my beloved extended family that I did not, in fact, belong. I kept my face covering in my pocket.

Humans’ tendency toward conformity is not all bad. In a now classic study from the 1980s, researchers investigated how to reduce water consumption in drought-prone California. Signs at the University of California, Santa Cruz asking students to turn off the shower while soaping up led to only 6 percent compliance. So researchers recruited male students to serve as norm-setting role models. These role models would hang out in the communal shower until they heard another student come in, and then soap up with the water off. When one role model soaped with the shower off, roughly half of the unwitting students also began turning off their faucets at soaping time. Compliance jumped to 67 percent when two role models followed the sign.

But conformity can also distort how we make decisions. For instance, in the summer of 2020, when the pandemic was still new, researchers asked 23,000 people in Mexico to predict how a fictional woman named Mariana would decide whether or not to attend a birthday party. Most participants believed Mariana should not attend. But when they read a sentence suggesting her friends would attend or that others approved of the party, their predictions that Mariana would also go increased by 25 percent, researchers reported in PLOS ONE.

My decision to conform to Disney normal ended predictably — with a positive COVID-19 test. After weeks of coughing and sleepless nights, though, my frustration is less directed at myself than at political leaders who so blithely ignore both epidemiology and human behavior research and tell us to live like it’s 2019. It’s not. Nor is it 2020 or 2021. It’s the murky year known as 2022. And the rules of behavior that bolster our social norms — such as role models who refrain from large, indoor, unmasked gatherings, and leaders who uphold mask mandates on public transit to protect the most vulnerable — should reflect this liminal space.