On Throw Back Thursday:
Why can’t ostriches fly?
Answer: Because the dinosaurs went extinct.
Amazingly, this is true of emus, rheas, cassowaries, and the extinct moa, too.
Read how it happened in this vintage 2010 article: Why Don’t They Fly?
(photo from Wikimedia Commons. Click on the image to see the original)
When it comes to disasters it’s hard to beat the asteroid that hit Earth 66 million years ago and wiped out three-quarters of the plants and animals, including the dinosaurs.
The asteroid hit near the Yucatan and fried everything within 1,500 km (930 miles) — a huge area that includes Cuba, Florida, and a wide arc to Myrtle Beach, Nashville, Dallas and central Mexico. The impact left behind a huge crater called Chicxulub, half of which is underwater today.
Last year geologists pulled core samples from the crater’s underwater peaks and discovered an amazing thing. Life came back to the crater’s edge in only hundreds, not millions, of years.
The pioneering organisms were microscopic plankton, members of Thoracosphaera (spheres) and Braarudosphaera (dodecahedrons), whose tiny shells were found just above the devastation line. Here are examples of these tiny structures, so small that they can only be seen with an electron microscope.
Even though the ocean was toxic at the time, plankton recolonized it rapidly after Earth’s fifth mass extinction.
Oddly enough, this makes me hopeful.
Based on Earth’s current extinction rate of 1,000 times the normal background rate (predicted to become 10 times worse) scientists believe we’re at the start of the sixth mass extinction. I’ve already seen population declines in many of my favorite birds and I worry for the future of all plants and animals … and humans, too.
Life came back really fast after the last mass extinction. I hope it will do so again.
Read more here in Science News.
(painting of asteroid impact by Donald E. Davis in public domain, Thorascosphaere photo from Wikimedia Commons, Braarudosphaera bigelowii image linked from DodecaBeing blog. Click on the images to see the originals.)
p.s. The February 13&20, 2017 issue of The New Yorker has a great cartoon about the asteroid. Click here to see.
And now for something completely different. Here’s a fact I found surprising. Maybe you will, too.
Did you know that silver kills bacteria?
And even weirder: Did you know silver turns dead bacteria into zombies that kill more bacteria? Here’s how.
It sounds wonderful but silver isn’t useful in every situation. Read this Wikipedia article about the medical uses of silver before you use it.
Weird and wonderful.
(photo from Wikimedia Commons. Click on the image to see the original.)
Last month I randomly opened an encyclopedia for the letter P and found an animal I’d never seen before. Though he looks like an anteater he’s not related to them.
Pangolins are mammals with long thin snouts and long tails that eat ants and termites. Instead of having fur they’re the only mammal on earth with scales. The scales, made of keratin like our fingernails, provide protection. When a pangolin is attacked it rolls into a ball in the same defensive posture as a porcupine.
Eight pangolin species range from Africa to Asia and Indonesia. All are in severe decline, listed as vulnerable to critically endangered, because their meat is a Chinese delicacy and folk medicine. Even African pangolins are poached for this illegal trade.
Anteaters can’t help them. They’re not related.
Anteaters are furry mammals with long thin snouts and long tails, native to Central and South America.
They, too, eat ants and termites.
Anteaters and pangolins resemble each other because they need the same tools to gather food. Similar appearance in unrelated species, called convergent evolution, is true of my favorite bird, too.
Peregrine falcons resemble hawks because they both hunt for meat, but peregrines are more closely related to parrots than to hawks and eagles. They converged in appearance to get the job done.
(photos and maps from Wikimedia Commons; click on the images to see the originals)
16 December 2016
Uh oh! Blue light, though bright, isn’t better at night.
As cities switch from incandescent or mercury street lights to LEDs they’re saving electricity and money and providing more light. But brighter isn’t better if it’s blue.
The video above shows how the color temperature of light matters to our eyes and sleep patterns. Though the video doesn’t mention it, the color also matters to birds and animals.
It’s possible to buy yellow-toned LEDs but blue, because its bright, has been the default choice for city lights. We didn’t know that color mattered when the world began switching to LEDs and the bulbs have such a long life it’ll be decades before it’s time to replace them. Meanwhile humans, birds and animals will be coping with the change.
It makes me want to close my eyes.
(credits are in the captions)
p.s. Here’s a really helpful video showing the difference between incandescent, compact fluorescent and LED light bulbs in home use (the A19 screw base). You’ll also see the inside of an LED bulb. I was surprised to learn it’s a tiny computer.
2 December 2016
In my blog two weeks ago, the night sky video Lost in Light made me wonder how we’ll ever see the stars again.
Since then I’ve learned that our outdoor lights waste money and energy, disrupt wildlife, and ruin our own sleep patterns. What we can do?
The video above from McDonald Observatory shows a simple answer. Use lampshades.
The quick demonstration below shows why.
Right now our cities and towns are switching out incandescent street lights for LEDs. It’s the perfect time to put on lampshades. You can shade your home lights, too.
p.s. The color of LED light matters too! Blue light versus red spectrum: Uh Oh! Blue Light Isn’t Better.
(videos from McDonald Observatory and darksky.org)
The Rainbow Bridge in southern Utah is a bridge of solid rock carved by water during the last ice age. At 290 feet tall it’s one of the highest natural bridges in the world and held sacred by Native Americans in the region. But it doesn’t stand still. Like all structures it moves in response to vibration.
Last year the University of Utah obtained permission to measure resonance at the Rainbow Bridge. Their report, published in Geophysical Research Letters, found that the bridge is affected by both natural and human activity. Wind can make it hum. Waves from man-made Lake Powell on the Colorado River, only a mile away, make it sway a little. During two days of measurements the bridge felt three earthquakes, one of which was a man-made earthquake in Oklahoma.
The report includes this animation of the Bridge’s movements. There are moments when it looks positively scary!
Read about how the Rainbow Bridge moves at Resonance in Rainbow Bridge: University of Utah study listens to the natural bridge vibrate and sing.
And speaking of scary bridge movements …
Man-made bridges are engineered to move just a little in response to wind and other forces, but they mustn’t move too much or they break. In a spectacular case of poor design the Tacoma Narrows Bridge, built to withstand 120 mph winds, collapsed on 7 Nov 1940 in a 40 mph wind only four months after it opened. The cause was attributed to resonance, though more recently to aeroelastic flutter.
Watch as the bridge collapses in the video below. Read the whole story here.
(Tacoma Narrows Bridge destruction, 7 Nov 1940, video embedded from Wikimedia Commons)
(credits are in the captions; click on the links to see the originals)
On Throw Back Thursday:
How many house sparrows equal a common grackle? Find out in this September 2009 article …
28 September 2016
Right now it’s flu shot season, soon to be followed by flu season itself from December to March.
Wild birds have been blamed as a source of influenza but new evidence indicates they’re not the cause of bad flu. To understand why here’s a primer on where flu comes from, how it spreads, and why flu season is in the winter.
Where does flu come from?
Other people! It spreads best — and quickly creates new strains — where people are densely crowded. Amazingly, the Spanish Flu Epidemic of 1918 spread quickly because of crowded camps and trenches in World War I. A new study this month from the University of Chicago finds that “surveillance for developing new, seasonal vaccines should be focused on areas of east, south and southeast Asia where population size and community dynamics can increase transmission of endemic strains of the flu.” Click here to read why flu does so well in that part of the world.
How does flu spread? In the air. We breathe it in. Airborne transmission actually explains …
Why is flu season in the winter?
Not too long ago we were told that it’s in the winter because migratory waterfowl pass avian flu to domestic birds during fall migration. Wrong!!
Recent studies of avian flu transmission show that it spreads in poultry factory farms (crowded conditions!) and along our poultry trade routes. It follows our poultry, not wild birds’ migratory paths.
And the timing has nothing to do with migration. Flu season is in the winter because the pathogen stays airborne longer in dry winter air. It falls to the ground in summer humidity.
So why are waterfowl off the hook?
Wild birds aren’t spreading the worst strains of avian flu because they don’t have it.
After the H5 avian influenza A virus hit U.S. poultry farms in 2014-15, officials worried that avian flu would return when waterfowl migrated south again … but it didn’t. The reason was found by researchers from St.Jude Children’s Research Hospital who “analyzed throat swabs and biological samples taken from 22,892 wild ducks and other aquatic birds collected before, during and after a 2014-15 H5 flu outbreak in poultry.”(*) None of the birds had the highly pathogenic influenza A virus.
“Bad flu is not our fault,” say the ducks.
Read more here at: Evidence suggests migratory birds are not a reservoir for highly pathogenic flu viruses.
p.s. Remember to get a flu shot! However, if you’re over 65 immunologist Laura Haynes says you should get it after Halloween if you can. Click here to read her advice on NPR.
(photo by Brian Herman)
After two days of sad stories about fish populations in decline here’s some hopeful news.
With sensible catch limits and sanctuaries where fishing is prohibited, we can turn the tide on ocean species decline — but only if we can enforce the laws. Unfortunately the ocean is a huge place with few “cops on the beat” and a lot of places for illegal, unreported, and unregulated fishermen to hide.
Until now.
Last week Oceana, SkyTruth, and Google launched the public Beta of Global Fishing Watch (GFW), a free online tool that allows anyone in the world to monitor and track the activities of the world’s largest commercial fishing vessels in near real-time.
Here’s how it works: Every ship over a certain tonnage is required to transmit Automatic Identification System (AIS) data containing its identity, location, course and speed. The data, received by satellites and accumulated since 2012, is used to plot each ship’s movements. To determine which boats are fishing vessels, Global Fishing Watch developed an algorithm that identifies fishing by the characteristic patterns it makes on the map.
The map shows no-fish zones and Economic Exclusion Zones where it’s easy to see if illegal fishing is going on. Vessels that turn off their AIS transmitters or purposely falsify their GPS data are automatically suspect.
Nations at the mercy of illegal fishing are happy to use GFW. In December 2014, when the tool was still in test mode, SkyTruth analyst Bjorn Bergman (from his desk in West Virginia!) saw a Taiwanese boat fishing illegally in Palau’s protected waters. And it turned off its AIS. The boat left Palau and headed for Indonesia. When it returned in January Bergman remotely helped Palau authorities chase it down. Read the whole story here at the GFW blog.
So if you’re wondering how the U.S. will stop illegal fishing in 582,578 square miles of the newly expanded Papahanaumokuakea Marine National Monument (surrounding the Northwestern Hawaiian Islands) the answer is:
We’ll catch them from the sky.
For more information, watch the video and visit the Global Fishing Watch website.
(video from Global Fishing Watch on YouTube)