When Rebecca Calisi first moved to New York City, she ran into two immediate concerns. First, the New York City Department of Health and Mental Hygiene had encouraged her to have her children tested for lead sometime that year, since the state mandates that children under 6 be tested on an annual basis. The idea seemed sensible, given they had moved into one of the city’s prewar apartments, which are notoriously full of lead paint. Next, she needed to find a new research subject. As a biologist with a specialty in avian biology, Calisi knew a readily available bird species would be best. And in a city like New York, there’s nothing quite so omnipresent as pigeons.

“You could walk outside and sit down on a bench and your subject would come right up to you,” she tells mental_floss.

It was only a short stretch for Calisi to connect the two items on her to-do list—lead levels and pigeons—and before long she was measuring the blood of pigeons from zip codes all over the city. What she found in her survey of 825 birds over five years correlated precisely with data from the city’s health department. Just like human New Yorkers, pigeons are very attached to their neighborhoods. They live in a small area for the majority of their lives, and the birds were exposed to many of the same sources of lead as human residents. Sure enough, her initial results showed that the birds’ blood showed similar levels of contamination. In other words, Calisi found, pigeons were like urban canaries in a coal mine. They were perfect biomarkers for lead contamination.

Now an assistant professor in the Department of Neurobiology, Physiology, and Behavior at the University of California-Davis, Calisi has a new study out in the journal Chemosphere detailing her findings [PDF]. The results clearly showed the link between the health of a city’s human inhabitants and its wildlife.

As cities and their populations expand, engulfing areas previously left for farmland or untouched wilderness, encounters between humans and wildlife are on the rise. Consider the coyotes roaming the streets of New York, or bears in cities all over Southern California. While these confrontations are often framed as antagonistic, viewed through the lens of biological research like Calisi’s, the encounters can actually be mutually beneficial.

For example, Calisi says, “If somebody had been monitoring the levels in lead in pigeons in Flint, Michigan, might there have been warning signs before children started getting sick?” Lead isn’t the only hazardous substance studying birds could detect. She hopes to expand her research to investigate other heavy metals, pesticides, pollutants, and fire retardants in other cities as well as more rural populations.

Calisi isn’t the only person intrigued by what the animals we live beside can teach us about our environment. Scientists at the University of Rochester Medical Center recently found a link between highway pollution and cardiovascular health. The Rochester-based team took lab rats on a road trip between Rochester and Buffalo. The rats, exposed to the same type of pollution as drivers or people living near highways, showed immediate health effects that lasted for up to 14 hours. Their heart rates quickly dropped after exposure to airborne pollutants, and their nervous systems were negatively impacted as well. The study offered new insights into why urban hospitals often seen an uptick in heart attacks on smoggy days.

Then there’s the paper that revealed how artificial lights impact the reproductive systems of European blackbirds (Turdus merula). A study by ecologists and evolutionary biologists at the Max Planck Institute for Ornithology in Radolfzell, Germany found that even low intensities of artificial light can alter the timing of reproductive development in songbirds. Birds exposed to light with an intensity even 20 times lower than the light emitted by a normal street lamp developed their reproductive system as much as a month earlier than birds kept in the dark at night. They also molted earlier. For humans living in the incandescent glow of urban areas, artificial light can be just as harmful: Disrupted circadian rhythms are linked from everything to metabolic disorders to an increased risk of cancer.

 
If it seems like city life is killing its inhabitants—feathered, furred, and bipedal creatures alike—there’s reason for hope. Urban wildlife don’t just reflect the risks of urban living; their rapid evolution hints at how humans might also change to cope. The pressures are undoubtedly great, but for animals that find ways to adapt, there are numerous opportunities to thrive. In one recent study, ornithologists showed that European blackbirds from cities are far less sensitive to stress than their rural cousins. The city birds had a much lower hormonal stress response, which scientists hypothesized could be the result of selective pressures in an urban environment.

These pressures make up a large part of what Jason Munshi-South, an evolutionary biologist, investigates from his lab at Fordham University. With a collection of students and colleagues, Munshi-South has tracked down white-footed mice [PDF] in slivers of parks throughout the city, as well as salamanders and rats. Creatures this small can roam throughout the city and incorporate human infrastructure into their daily needs—though, like pigeons, they tend to stick to a small home area. White-footed mice and salamanders have found a way to exist in tiny pockets of wilderness, surrounded by the rush of 8 million people. And those challenges have led to some surprising rapid adaptations.

“They’ve evolved to eat different diets, to deal with pollution. Their overall life history may evolve if populations are crowded—they’ll have offspring at a younger age. Those are the things we found with white-footed mice,” Munshi-South explains to mental_floss. “With rats, similar things are going to apply. You’ll see adaptations in the skeleton for living in different structural environments.”

For example, he says, “You have a lot of rats in New York City living in underground infrastructure and coming up and down, not burrowing into the ground.”

 
Genetic tests on the rodents have revealed that these changes extend even into the animals’ genomes. Munshi-South said they found evidence that the city critters are becoming distinct from their country relatives simply because of the extreme pressures to survive. And while the differences aren’t yet large enough to separate the two groups into distinct species, it’s a possibility in the future.

The ability of these animals to adapt and thrive in city environments—to live alongside humans and even act as early warning systems for certain pollutants—might seem to suggest that nature will triumph in the face of human progress. But neither Calisi nor Munshi-South are particularly optimistic when it comes to conservation.

“I guess we’re lucky that some species can live in cities and adapt, since most of them can’t,” said Munshi-South. “But I don’t think we’ve figured out a good way to use urbanization as a tool to prevent broader habitat loss yet.”

Calisi just hopes that the species who do manage to build niches in cities will stop being regarded as nuisances or invaders. Instead, she says, we should view them as partners—and acknowledge that we’re all in this rat race together. 

Attention, travelers (and Guinness World Records officials): Austrian airline People’s Viennaline claims to have launched the world’s shortest international flight. The Points Guy reports that the trip—which transports passengers 13 miles from St. Gallen, Switzerland to Friedrichshafen, Germany—takes only eight minutes.

The regularly scheduled, twice-daily flights will officially began on November 2, 2016. Passengers will fly on a 50-seat Embraer 135 jet, and tickets will cost around $45 (including taxes and fees).

St. Gallen (which serves as capital city of the canton of the same name) is a little over an hour’s drive away from Friedrichshafen, a German industrial center. The two are separated by Lake Constance, and the car trip around the body of water is about 47 miles long. In contrast, People’s Viennaline’s new flight zips directly across the lake—a route that’s only 13 or so miles.

The airline isn’t simply trying to provide day-trippers with an easier journey, or worm its way into the record books: According to The Daily Mail, People’s Viennaline wants to use the eight-minute journey as a feeder flight so travelers can connect with their Friedrichshafen-Cologne route.

Curious which airline holds the current record for shortest domestic flight? That would be Loganair’s mile-long journey from Westray to Papa Westray in Scotland’s Orkey Islands. The trip takes 47 seconds, and covers a little over a mile. In contrast, the world’s longest nonstop flight goes all the way from New Zealand to Dubai, and takes more than 17 hours.

[h/t The Points Guy]

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National Geographic has a new web series called Ingredients, in which chemist George Zaidan walks us through the ingredients in typical household materials. First up is a video about toothpaste. Zaidan checks the ingredients list and explains what everything does, discusses the history of toothpaste, and even gets into how you can make toothpaste at home.

What’s impressive about this video is that Zaidan actually explains the chemistry of these ingredients and what they do. It would be easy to make a few wisecracks and move on, but this video is genuinely educational. Learn up!

From the YouTube description, here’s an important update:

UPDATE: Since we filmed this video, the FDA has banned triclosan and 18 other ingredients from “consumer antiseptic wash products” (aka soap). You can read the details below, but the FDA is basically saying that none of these ingredients clean your hands any better than plain old soap and water. The FDA did not ban triclosan from toothpaste, but you can easily check whether your toothpaste has it by checking the ingredients label. Triclosan would be listed under “Active Ingredients” in the “Drug Facts” box on the back of the package. Most toothpastes don’t have triclosan, so you can choose to brush without it if you’d like.

A group of West Coast tech entrepreneurs are so confident self-driving cars are the way of the future, they want to dedicate an entire highway lane to them. CBC News reports that Madrona Venture Group, which is made up of several high profile tech industry experts, recently released a report proposing that at least one lane of the I-5 highway connecting Seattle and Vancouver be given over to autonomous cars.

The report addresses American and Canadian policymakers, arguing that self-driving cars will soon begin to take over the roads, and that dedicating an I-5 lane to them would make transportation easier between the two tech hubs. Madrona wants autonomous cars to begin by sharing an HOV lane with regular vehicles—as autonomous cars become more dominant, however, Madrona believes it will be necessary to give them exclusive use of an entire lane.

An autonomous car lane would make commuting more appealing and save money, Madrona says. Instead of spending money on expensive train tickets, or wasting hours behind the wheel of a car, commuters would be able to relax in the back of their own self-driving car or a shared taxi-style autonomous van. Additionally, Madrona argues, the autonomous car lane could serve as a cheap alternative to large-scale transportation projects, like the high-speed rail that has been proposed to connect Seattle and Vancouver.

Ultimately, Madrona argues, the autonomous lane could revolutionize commuting. “The principal benefit is that it allows drivers to recapture all the time otherwise spent behind the wheel,” the report explains. “This is at least two and one half hours from Seattle to Vancouver. Imagine being able to watch a video or sporting event, prepare for a business meeting, work on your novel or plan a game with your children.”

[h/t CBC News]

China’s massive Three Gorges Dam is 600 feet tall and home to what is probably the world’s largest elevator. The impressive feat of engineering can lift up to 6.7 million pounds, although it generally does not lift more than 3000 deadweight tons at a time.

As seen in the video below (spotted by Gizmodo), large ships enter the loading dock filled with water, and then the lift carries them to the top or back down in about 40 minutes. It’s estimated that the lift will get an extra 6 million tons of goods through the dam each year.

While dams are useful for controlling the flow of water and generating power, drastically changing the water heights on each side of the dam can make getting ships across a challenge. Most dams have adopted a lock system that can slowly get ships across by locking the boats in chambers and adding or removing water.

Three Gorges Dam also has a lock system in place, but that system has two series of ship locks that consist of five stages each, which can take a while. The long process takes about four hours, which is a lot longer than a (relatively) quick trip in an elevator.

[h/t Gizmodo]

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The little pinprick spots on apples, pears, and potatoes are called lenticels (LEN-tih-sells), and they’re very important.

Plants need a constant stream of fresh air, just like people, and that “fresh air” means carbon dioxide. Flowers, trees, and fruit all take in carbon dioxide and give off oxygen. But unlike people, plants don’t have nostrils.

That’s where a plant’s lenticels come in. Each little speck is an opening in the fruit or tuber’s skin or the tree’s bark. Carbon dioxide goes in, and oxygen comes out. Through these minuscule snorkels, a plant is able to “breathe.”

Like any opening, lenticels are vulnerable to infection and sickness. In an apple disease called lenticel breakdown, a nutrient deficiency causes the apples’ spots to darken and turn into brown pits. This doesn’t hurt the inside of the fruit, but it does make the apple look pretty unattractive. In the equally appealing “lenticel blotch pit,” the skin around the apple’s lenticels gets patchy and dark, like a weird rash. 

The California Academy of Sciences has a live Shark Cam on YouTube. It shows an HD underwater view of a shark lagoon, and it even works at night (in black and white night-vision mode).

The display is very soothing, though the actual shark content is quite low. If you like watching rays cruise by—and who doesn’t?—you’ll love this. You may also enjoy putting it on as soothing background video. Chill out and watch:

If you’re curious what species you’re seeing, check this field guide. Long story short, it’s tons of rays (of various species) and diamond fish. If you want more sharks, check out the Monterey Bay Aquarium’s Shark Cam.

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