Superstar—Part 1

Back in 1971 Andrew Lloyd Weber and Tim Rice—two very talented Brits—conceived of the rock opera “Jesus Christ Superstar” and ushered in a new kind of entertainment, as well as provoked a lot of people to rethink the story of Jesus. I recently watched the 1973 movie once again—an inspired production filmed in the beautiful Israeli desert. I love the music!

What Sir Andrew and Sir Tim couldn’t anticipate was that decades after their opera, another type of superstar would be discovered—this time not by a couple of talented Brits, but by a skilled Israeli astronomer. Avishay Gal-Yam has an article in the June 2012 issue of Scientific American magazine, titled “Super Supernovae,” that describes how he and associates came upon these superstars. (Maybe super superstars?)

Prior to this discovery, the accepted wisdom in the astronomical world was that the largest a star could get was maybe as much as 100 times the size of our sun. There are many kinds of stars in our majestic universe—with a wide range of size, temperature, color, brightness, age, and number (single, double, or even triple stars). Each kind has its own type of life history. Every star winks into existence when a cloud of interstellar gas (almost completely hydrogen) collapses on itself and ignites under tremendous gravitational pressure, kicking off a nuclear fusion process. The star emits its shine for millions or billions of years, as the hydrogen fuel becomes slowly fused into helium.

When the hydrogen begins to run out is when stars get interesting. Their next act is a dying one—sometimes far more dramatic than what Shakespeare conjured up in “Romeo and Juliet.” The nature of that swan song depends mostly on the size of the star. Every star begins to collapse into itself, when its fuel diminishes. Some (like our sun) will then swell into red giants, and what’s left after that will then shrink back to a white dwarf. If the dwarf has a partner (part of a double star system) that’s still burning, the dwarf may steal some of its partner’s fuel and later explode into a nova. They are called that because, to the ancients (who were very familiar with the night sky), the explosion suddenly became very visible to the naked eye and seemed to them to be a new star appearing in the heavens.

More superstars next time…

Orange Newt

Corvid Mobsters—Part 2

I have wondered why it is that hawks allow themselves to be shoved around by a bunch of smaller birds (or the same for a crow being mobbed by songbirds). Sure, it may be outnumbered, but in short order a hawk could easily dispatch an overly aggressive and foolish crow—sending the others fleeing through the trees. I’ve watched a hawk try to ignore the mobbing flock, but subsequently choose to flee, with the crows diving and swooping from behind. The hawk doesn’t seem to be inclined to retaliate. Why not?

A little research told me that even though a hawk could easily kill a crow, the act may require an expenditure of too much energy. Food is not always plentiful for flying carnivores. Crows are agile aerial acrobats, and a hawk would likely have to work hard to catch one. It maybe just ain’t worth the effort, so it vacates the scene. Besides, a hawk is not all that territorial. If it just happens to be sallying through, it has no investment in the area, so it allows itself to be driven off. If the hawk has its own babies to protect, however, it’s a very different story. In this case the crows know it and don’t push their luck. Just a little mobbing noise to warrant their awesome reputation and then move on to easier targets.

This crew of crows that I heard the other evening kept up their raucous chorus for about a half hour, as the scene of the action floated through the woods. It suggested to me that they had themselves a real target and were not just playing or bluffing. In time, they calmed down, and quiet once again reigned in the woods. Then, after a while, I could hear one lone hawk plaintively calling out from the direction of where the mobbing had ended. It sounded weak or defeated. I tried to guess whether it was crying out of pain, or a dented ego, or just sassing back. It was not a happy or triumphant call. I think that crows prevailed on that one.

Dropped Blue Jay Feather

Left click for larger image.

Corvid Mobsters--Part 1

I recently listened to a horde of crows noisily and persistently squawking, cawing, and bellowing off in the woods. I could not see them to know who or what they were hassling, but it seemed to be a case of what is called “mobbing”: when a group of birds surrounds and attacks a larger predator or threat. I’ve watched a group of songbirds mob a crow that posed a threat to their babies. I’ve watched a band of crows mob a hawk, although I couldn’t figure out quite why the hawk was being targeted.

Maybe that’s what I was hearing the other day: crows mobbing a hawk? (They also mob owls and even raccoons, foxes, and house cats.) After nearly half an hour, the ruckus moved several hundred feet down the hill, toward the creek. This suggested to me that the crows were mobbing a bird that flew that way, rather than a mammal, since they remained in the trees and moved rather quickly. But what was really going on? I don’t think the crows were defending their babies—it’s late enough in the season that all youngsters would be fledged and pretty much on their own by now. Could the youngsters be playing some kind of game among themselves?

Crows tend to hang together in colonies, so when a threat is spied, they can depend on a group to quickly form, to harass and drive off the menace. They have several possible motivations for mobbing a larger bird: They may be defending their nests of eggs or nestlings. They may be protecting their food supply—crows are also predators of songbirds and other small critters. They may be teaching youngsters how to mob. Earlier in the season they may be showing off to potential mates. (“Hey, sweetie, see how brave I am? Want to hook up with me?”) Or maybe they’re just playing. Sometimes crows—especially young ones—will play a game of hide and seek, wherein the “it” crow tries to hide and the others fly about and shout at the hider, once he’s been spotted.

When crows mob, they are either trying to drive away a predator or simply alerting all birds in the vicinity that a pariah has entered the neighborhood. A hawk or owl may simply be passing through and resting on a branch for a few minutes—unaware that it has violated corvid territory. The crows’ frenzy is an ambivalent mixture of fear and aggression—fear for their individual safety and a boldness engendered by the need to appear formidable. If you watch crows mobbing a larger bird, you can see a fascinating dance, wherein each one tries to do it from a safe distance, while seeming to be fierce and intimidating. Like teenage urban boys bluffing, they sound as if they’re calling out, “Hold me back, boys, before I pound his ass into the pavement!”

The objective of mobbing may be to engage the intruder in multiple dive bombings and buzzings, to prevent the larger bird from being able to focus on one target. Keeping him distracted, they swarm around and cause the hawk to leave, just to get a little peace for itself. Or the crows may be attempting to teach a young hawk or owl to give crows a wide berth in the future: If they get one of their band to act as a decoy—causing the hawk to focus forward, as the others attack from behind—the young hawk might conclude that a crow is one of those magical critters that will fly in your face, as it simultaneously pecks at your butt. If that impressionable young hawk spreads the news by telling its buddies what happened, the crows will have achieved a great coup. The crows may even top off the humiliation by defecating on the hawk.

More on mobbing next time…

Concrete Block Makes a Solid Toad Abode

Granddaddy Red—Part 2

One of these harvestmen visited me the other evening, as I soaked in the outdoor tub. He had an attractive red body (most of them are gray or brown, so that caught my attention right away). I’ll call this guy “he,” because he was rather small, and male harvestmen are more diminutive than “harvest women.” Males are also more colorful, and this guy was pretty snazzy looking. So I’ll call him Granddaddy Red, or just Red for short.

I have a wooden paddle laid across the top of the tub, with which I occasionally stir the water, to even its temperature. (On winter nights, the water near the bottom of the tub cools quite quickly and needs to be stirred often, lest my butt get cold.) I first spotted Red as he sauntered down the paddle, towards me. When he reached the end, less than a foot from me, he stopped, waved a couple of legs out into space, and seemed confused that his plank road had come to an abrupt end. He stood still, lifting first one leg then another—appearing to be testing the solidity of air. Since I don’t wear my reading glasses in the tub and dusk was rapidly approaching, I was left wondering what he was up to. Guess I’ll have to live with the mystery.

I soon lost track of Red, as I sunk back into my soaking reverie. Darkness began to descend. A few minutes later, I absent mindedly picked up the paddle, stirred the water, and set it back down again. Something tickled the back of my hand. It was Red! My hand had apparently given him a way to continue his stroll forward. Not wishing to drown him. I tried to urge him back on the paddle, but he was having none of that. “Been there, done that… I’m moving on!” So I held my hand out to the wall next to the tub and Red promptly stepped off, climbed up the wall, went over the top, and was gone into the night. He’d found a way to keep heading south, using my hand to boost him along. Farewell, Red! May the road rise to meet you.

There is an urban legend that, although daddy longlegs are very poisonous, their fangs are too small to puncture human skin. As is the case with most urban legends, neither of these beliefs is true. First, they have no venom. Second, their fanglike mouthparts are able to take a harmless bite out of you, but why do so when you may get squashed in the process by the two-legged monster? No, they are innocuous.

In fact, harvestmen are quite beneficial to our world. They are scavengers, chowing down on decaying plant and animal detritus. They are also helpers in the garden, since the other half of their diet consists of aphids, flies, mites, wee slugs, and other tiny pests. They are mostly active at night, so we don’t get to watch what they are up to.

American Indians called them “Grandfather Graybeard.” I find it fascinating that different cultures often have such similar names for nature’s critters. So why is a dragonfly called an “eye-poker” in Sweden and an “adder’s servant” in Wales?