Thirsty crows and true fables

Remember Aesop's fable about the thirsty crow? The one that finds a half-filled glass of water, but isn't able to reach it's beak down into the glass to drink. Not to be discouraged, the crow gathers rocks and stones, dropping them into the glass and raising the level of water, until at last, it's able quench its thirst.

I read the fable at some point, probably in English class, and always thought it was a lesson in persistence and creative thinking. I didn't know it was a real phenomenon.

But it is. When presented with a similar situation - this time, with a bit of meat on a styrofoam disk floating in a tube of water for extra motivation - New Caledonian crows  drop in rocks to raise the water level until they can reach the meat.

Through a range of challenges, the crows prove their causal thinking skills. If researchers set out heavy stones and "imposter" styrofoam stones, the crows preferentially choose the the heavy stones that will raise the water level. And if crows are presented with two tubes with food, but one with an already high water level and the other with a low water level, they go first to the tube with higher water.

Crows are smart. Their intelligence rivals that of dolphins and orangutans, and is up there with that of young children.

I used to think of crows as pests. After all, they made a mess at dumpsters and ate Robin eggs and blared their loud "caws" in nearby trees. But now, when I see a crow, I watch carefully to see what it's going to do next. Because it just might be something really interesting.

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some info from: Jelbert SA, Taylor AH, Cheke LG, Clayton NS, Gray RD (2014) Using the Aesop's Fable Paradigm to Investigate Causal Understanding of Water Displacement by New Caledonian Crows.

Life that glows

As a child, I loved watching fireflies light up the dark corners of our backyard. But I never thought to ask how a little bug could make it's very own light. 

Photo by Smoken Mirror on Foter.com

It turns out that making light all comes down to energy and some special molecules (luciferin, and the enzyme luciferase). Those words both come from the Latin "lucifer" or "lightbringer." You might recognize "Lucifer" from the Bible - he was the angel who wanted to be more powerful than God and ended up falling from heaven to hell.

But back to glowing things (which also include certain mushrooms and marine creatures): the luciferin molecule uses energy to react with oxygen, and the luciferase enzyme speeds it all up. Through the reaction, electrons in the luciferin molecule are excited, or have a little more energy than normal. When the electrons relax and go back to their normal state, that extra energy is released as light.

Amazingly, this whole process of bioluminescence is super efficient: most of the energy (up to 80 or 90 percent) is transformed into light. An incandescent lightbulb, by comparison, transforms less than 5 percent of the energy it receives into light (90 percent turns into heat), while LEDs come in at 20 percent. So while a lightbulb gets warm when it glows, fireflies and mushrooms do not.

For fireflies, the light can help attract mates and show predators they don't taste good. For mushrooms, a recent experiment showed the light may help attract insects, which then help spread the mushroom's spores.

Unfortunately for me, there's nothing glowing in the high rockies - I'll just have to Youtube glowing creatures to get my bioluminescence fix. Unless I can grow these myself...

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image credits: Photo by Smoken Mirror on Foter.com

Where crows wander

Crows are found all over the world. Usually, they hang out near people - cities, suburbs, anywhere with a good dumpster that's often filled. But they can still be found in the wild. The desert, the mountains. Probably returning often to the beaten paths, picking up the leftover beef jerky or bits of granola bars that hikers and bikers and campers have left behind. 

I've seen them out there, in the not-so-faraway wild. Soaring up above 13,000 or 14,000 feet. Getting a view worthy of angels, as they loop and dive through breezes and winds. I've seen them in canyons, too, where ancient art sits on rust-orange rock walls, and silence winds around you like a thick blanket. And I've seen them on city streets, working together to corner a mouse or flying away with a hot dog bun in beak.

Next time you're outside, anywhere, don't be surprised if you find a few crow companions. Maybe you'll hear them first - the long, cra-craaa that echoes and splits the silence. And then, if you look up, you might see one or maybe two, sliding through the air, wings outstretched and steady, catching the wind.

Ode to my heart

It was just February. American Heart Month. A good time to step back and give thanks for this muscular organ that works constantly, every day of our lives.

Design a machine that pumps every second of every day, without stopping ever – not for maintenance or a vacation or just to take a break. Instead, it pumps constantly for 36 years.  37, 38, 80 years, more. Lots and lots of pumping.  A technological marvel.

And that’s what you do, my heart.

You’re the size of my fist. But you pack a big punch. The center of my circulatory system - pump, tubes, fluid. Simple, really.

Push blood to the lungs, where the blood picks up oxygen and drops off carbon dioxide, waste; then push blood out through the body, within a few cell widths of every single cell, so it can drop off oxygen and pick up carbon dioxide, waste. Miles and miles of blood vessels.

I’ve never been around the world, but it’s like my blood goes there every day. Twice. Because there are 50,000 miles of blood vessels in my body. Two trips around the earth, at its equator. All right here.

Pump, tubes, fluid.

Lub-dup, lub-dup, lub-dup.

Beat, beat, beat.

I walk through every day without giving you a second thought. 

But tonight, for just a second, I stop. And I listen. In thanks.

For you, my circulatory system. My blood vessels. My blood. My heart.