Why Do Pirates Love Parrots? (24 page)

W
e’ll give you the executive summary first. When a vulture circles before eating, there are probably one or two reasons for the behavior—it is checking to make sure that the prey is actually dead or it is looking for other possible predators, especially land predators that might serve as competitors for the food. Vultures are eaters, not fighters, and neither want to kill a potential food source nor fight four-legged or winged competition for a meal.

But the executive summary leaves out a lot of fascinating information about vultures and the most shocking surprise ending since
Psycho.
There are three different species of vultures found in North America. The turkey vulture (mistakenly called buzzards by many) is by far the most common, found in all fifty of the United States, Canada, and Mexico. The black vulture generally is found only in the southeastern United States, and the California condor (despite the fancy name, it’s really a vulture), nearly extinct just decades ago, can be found in the wild not only in California, but also in Arizona and Baja California, Mexico. Unless otherwise specified, we’re talking primarily about the turkey vulture in this discussion.

One of the big differences between turkey vultures and their two relatives is that the turkey vulture has a strong sense of smell along with excellent vision. Another difference is that turkey vultures tend to fly lower than the other two species. These two distinguishing characteristics are likely not a coincidence, as one of the ways in which the vulture identifies its prey as dead is by smelling mercaptan, a gas emitted by decomposing carrion. The very smell that disgusts us is like the aroma of freshly baked chocolate-chip cookies to them. Ornithologists have tested vultures’ sense of smell by hiding carrion; the vulture can find the dead animal just from the odor.

Vultures may be scavengers, but they do have strong preferences in food. They choose to eat herbivorous animals, such as cows and deer, over meat-eaters like dogs, cats, and coyotes, although if hungry enough, they’ll settle for the less tasty carrion. They also have a strong preference for freshly killed meat over decomposed carrion, but because their beaks are relatively weak, they have problems penetrating the hides of animals. Black vultures and California condors have stronger beaks, and they occasionally “share” a meal of carrion that the turkey vulture could not polish off alone (it is far more likely, though, that the black vulture and condor will chase the turkey vulture off the prize, without so much as a finder’s fee as recompense). More often, the turkey vulture bides its time until it can devour the carrion itself.

Ready for the surprise ending? Most of the experts we consulted did not agree with the premise of the question. One turkey vulture expert, who prefers to remain anonymous, rather angrily pointed us to the FAQ (frequently asked questions) section of the Turkey Vulture Society’s Web site, which clearly states: “Contrary to popular belief, vultures do not circle over dead or dying animals.”

How can we account for the “myth,” then? To conserve energy, vultures flap their wings as little as possible. They can soar for great distances and long periods of time by taking advantage of thermals—updrafts of rising, warm air. Because of the birds’ less than sterling reputation, human bystanders might assume that the vultures are circling prey, but turkey vultures often circle together in thermals just to gain altitude—if they catch the drafts properly, they can soar for hours without flapping their wings.

Black vultures are much more social than turkey vultures. When they encounter large carrion, they often fly above the prey to attract fellow vultures to help polish off the carcass—the behavior isn’t necessarily altruistic, as there is safety in numbers. The black vultures are well placed to see turkey vultures below them, and can pick off a discovery from a turkey vulture. One turkey vulture has a good chance to fend off a single black vulture, but not a flock of them.

Whether we call it soaring, circling, or hovering, the vulture is careful to make sure its prey is dead before hitting the ground, and careful to look for competition from other birds and animals. But all experts agree on one thing—once the vulture thinks that all signals are go, it doesn’t dilly-dally: it swoops in quickly and chows down!

Although vultures may have many competitors for food, they have few natural predators, which is lucky for them, for they have few weapons in battle. Their best shot at deterring enemies is a direct result of their less than appetizing diet, as Sy Montgomery, in his article, “Heavenly Scavengers” in
Animals
magazine, explains:

Submitted by Susan Friend-Trommatter of Surry, Virginia.

T
he “SysRq” key, short for “System Request,” is one of those features added by computer geeks to let us average users know that we are but mere interlopers in their world. The good news is that pressing the SysRq key (sometimes labeled “Sys Req”) by mistake is unlikely to do any damage to your computer session. The bad news is that pressing the SysRq key is unlikely to do anything at all.

On most PC keyboards, the SysRq key shares a key with the Print Screen command, which has the virtue of actually doing something (creating screen shots of what you see on your monitor), but usually only if preceded by pressing Ctrl + Alt. In other words, if you are word processing and mistakenly hit the Print Screen/SysRq key, nothing seems to happen (in some systems, hitting Print Screen will make a copy of the screen on your clipboard).

At one time, IBM had great hopes for the now obscure SysRq key. It appeared as a function key on the keyboards used to control IBM’s popular 3270 terminals (designed to interact with IBM’s mainframe computers). SysRq allowed users to directly communicate with the underlying operating system to, say, switch sessions on the host server. Circumstantial evidence indicates that IBM had the same role in mind for the key for personal computers, as SysRq did not appear on the 83-key PC/XT keyboard but became the 84th key on the AT keyboard (designed to work with Intel’s then-snazzy 286 processor) in 1984. But most programs never took any advantage of the opportunity to develop this “attention” key.

SysRq is making a bit of a comeback, though, as the free and open-source operating system, Linux, offers users a “magic SysRq key.” Once this feature is enabled, by pressing Alt + SysRq, users can communicate directly with the underlying operating system. Once invoked, the magic SysRq key can do things like reboot the system when it is unresponsive to the usual methods or dump current memory to your console, helpful when debugging.

Although keyboards now sport twenty more keys than they did when the AT keyboard was king, most popular programs seem to utilize fewer function keys than ever (when’s the last time you used the “Scroll Lock” key?). But excising a key from the computer keyboard, even if it usually lay untouched, is harder to accomplish than scrubbing a pork barrel project from the home district of a member of the House Appropriations Committee.

Submitted by Darrell Wong of Pearl City, Hawaii.

I
t’s probably not a coincidence that this question came from New York City; we’ve seen this curious behavior most often in big cities. Sometimes when we are confronted with a new Imponderable, we play a little game of Malarky, and try to come up with bluff answers. In this case, we could think of at least three cool alternatives:

1. A.
   If you’re stopped safely at a stoplight and put the car in Park, the car can’t move accidentally. It’s done for safety reasons.
   
2. B.
   Putting the car in Park puts less wear and tear on the brakes.
   
3. C.
   Putting the car in Park allows drivers to rest their legs and feet.
   

When we posted this Imponderable on a couple of discussion forums for cabbies, the drivers let us know quickly that the correct answer is C. They thought the answer was obvious and let us know it:

No sir.

While agreeing with the main point, cabdrivers pointed out another benefit of putting the car in Park. By making sure the car is stopped, it’s safer and more convenient for a driver to goof around (e.g., reading the newspaper, checking out the legs on a fetching passerby, or changing the radio station) or to conduct business (particularly, paperwork necessary for their job).

As for the other Malarky bluffs, “A” makes sense, especially if the driver is distracted or is stopped on an incline. But “B” is pure hooey; constantly shifting the gears is more likely to put wear on the transmission than applying foot pressure, when stopped, is going to burn out the brakes.

And the “foot relaxation theory” explains why cabbies throw the car into Park more in big cities, where there is more stop-and-go driving—with the emphasis on
stop.

Submitted by Alona Amsel of New York, New York.

T
hey may not be much to look at, but utility poles are among the superstars of treedom. Although all logs might look alike to the layman, phone and utility companies pay several times the going price for the logs that become telephone poles, because the specifications are so strict. Although the individual utility rather than the government sets its own specifications, utility poles are expected to meet the standards set by ANSI (American National Standards Institute) and the REA (Rural Electrification Administration).

Logs are bought from outside vendors, sometimes via competitive bidding. The most common types of trees purchased are pines (especially Southern yellow pines), cedar, and fir. Specifications set by the utilities include requirements for height (a typical tree is thirty to forty feet high), width, treatment (most logs are treated to prolong their life), maximum taper (the ideal pole is as straight as possible), and the number and tightness of knots (the fewer the knots, the better).

Traditionally, logs have been treated with creosote, a liquid derivative of coal tar that has been the most popular wood preservative. The loggers are motivated to take this extra step because many utilities insist on warranties for a certain “life” of the pole (typically, twenty to thirty years). With particularly durable woods, such as cedar, sometimes only the portion of the log set into the ground is treated. As the rule of thumb is that ten percent of the log’s height plus two feet need be inserted, about the first five feet of the “butt” of the log is underground. Many logging concerns now use the synthetic pentachlorophenol (PCP) as a wood preservative. Isn’t PCP a carcinogen? Yep, but then so is creosote.

Submitted by Robert Holiday of Royersford, Pennsylvania.