City Streetlights, Even Stoplights, Blink a Bright Red and Green
Not only are Christmas lights bright enough to see from space, they also give NASA clues about who heads home for the holidays and who stays put. Satellite data shows that in the US, “nighttime lights shine 20 to 50 percent brighter during Christmas and New Year's” compared to the rest of the year. Lights increase especially in suburban areas, where people tend to celebrate at home and have bigger yards (all the better for those inflatable snow globes and festive Snoopy doghouses).
Austria’s Underwater Hiking Trails
Act now, while you’ve still got time to book a chilly springtime scuba diving trip to Austria’s underwater park. “Hiker’s paradise” Grüner See (Green Lake) is usually not a lake at all, but when snow starts melting off the Hochschwab Mountains in the warmer months, a 40-foot-deep, emerald-green, crystal-clear lake emerges. The photos in this gallery showcase submerged hiking trails, grass, trees, and even park benches.
Singing Mice
In 1926, a man was convinced he had a singing mouse in his house. Apparently it sounded so much like a bird that he caught it, put it in a cage, and gave it to some scientists, who wrote an article about their observations. But no one really did anything about it until recently, when behavioral ecologist Matina Kalcounis-Rueppell started analyzing unusual sounds she noticed in her California forest field site. Her research suggests that some mice really do sing: not only that, but the songs may be specific to males or females, differ across species, or even get more complex as the mouse gets older (and presumably wiser).
Smithsonian’s report reminds us that there’s always more than meets the eye:
Her discovery reminds us that each species perceives the world in a unique way . . . and so finds itself in a slightly different world. … Ants see polarized light. Turtles navigate using the earth’s magnetic field. Birds see ultraviolet markings on flowers, signs invisible to us.
Don’t miss last issue’s feature on mice, “Born to Be Wild.”
Blue-Eyed Reindeer
Speaking of ants seeing polarized light, a 2013 article in Proceedings of the Royal Society described how reindeer eyes change color with the seasons, from gold to icy blue. “This is the first time a color change of this kind has been shown in mammals,” University College London neuroscientist Glen Jeffery told reporters. The changes helps reindeer adjust to the extreme climate conditions of the arctic, where summer comes with continuous daylight and winter means continuous darkness. In the winter, when their eyes are blue, reindeer have a sort of night vision and increased sensitivity to light. Jeffrey’s team earlier demonstrated that reindeer can see ultraviolet, handy during those dark nights—and maybe on foggy Christmas Eves. The blue in the winter eyes seems to help with ultraviolet sensitivity.
