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Predators eat rotten meat, lightning strikes fish, Everest scrapes the stratosphere

Q: Why are predators and, of course, scavengers unaffected by rotted meat? Scott, Tucson, Arizona

A: Predators and scavengers can eat rotted meat thanks to a germ-hostile digestive system. All vertebrate predators have remarkably similar systems: a short pipe — six times the body length — with a bulge (the stomach) in the middle.

Wolf and scavenging ravens feeding on elk that the wolf killed. [Douglas Smith, National Park Service]

Because it’s short, food doesn’t stay long in the gut. Bacteria have little time to multiply and cause problems. The stomach, moreover, brews a vicious batch of hydrochloric acid that not only dissolves gobbled meat and fat but also kills most bacteria and other microorganisms.

"Practically the whole gastrointestinal tract of a carnivore is sterile," says Barry Groves, British nutritional scientist.

Rotting meat is rich in protein, amino acids, fat, lipid components, and minerals. Scavengers usually find dead meat soon after a kill so it loses little nutritional value. Eating rotted meat helps the species to survive.

"Hunger will drive most animals to feed on what’s available," says Dan Stahler, project biologist with the Yellowstone Gray Wolf Restoration Program, National Park Service. "These meat eaters can handle a high bacterial load due to their short digestive system and appropriate digestive enzymes and acids."

So can we. In Europe, people "regularly hang beef three weeks in a fridge before eating it," says Groves. Inuits leave fish to rot for months. By then, according to the anthropologist and Arctic explorer, Vilhjalmur Stefansson, it has the consistency of ice cream. "At first repelled, he grew to like it," says Groves.

Further Surfing:

Second opinions: The design of our digestive organs and digestive enzymes today by Barry Groves

University of California, Berkeley: Scavengers benefit by dining with wolves by Dan Stahler 

Lightning strikes fish

Q: If lightning strikes the ocean, do the marine animals get hurt or killed? Vicki, Sault Ste. Marie, Minnesota

A: A single lightning stroke can deliver a billion electron volts and 100,000 amps. Air within a lightning stroke can be hotter than the Sun’s surface.

Lightning hitting the open ocean [Moonraker Australia Communication Systems]

So, yes, if such a lightning bolt directly hits a marine animal swimming on the surface, it will undoubtedly hurt or kill her.

But, that’s not quite your question. What if the bolt strikes the water nearby the animal? Lightning comes in all shapes and sizes. What if it’s a lesser discharge? Ah, this gets tricky but it would probably harm her, at least. If she’s down deep, though, she’s safe.

When lightning strikes the ocean or other large water bodies, it spreads out over the conducting surface. It also penetrates down and can kill fish in the nearby region, says Don MacGorman, physicist at the National Severe Storms Laboratory (NSSL).

"Lightning strikes have killed or injured people on the surface more than 30 yards away," says David Schultz of the NSSL.

In fact, the 45^th Weather Squadron lists water as the second most dangerous place to be during a thunderstorm. (The first is an open field.)

Lightning, however, rarely strikes most of the open ocean although some sea regions are lightning "hot spots". The Gulf Stream, for example, where fish abound, has as many lightning strikes as the southern plains of the USA.

Lightning-producing storms arrive on the west coast of the U.S. frequently during the winter, says Schultz. "Winter storms passing off the east coast often erupt with electrical activity when they cross the warm waters of the Gulf Stream."

But, as Schultz says: "We really have no idea about the mortality rate of marine animals due to thunderstorms." Fortunately, only 10 to 20 percent of humans hit by lightning die and probably the same holds true for the animals.

Further Surfing:

NOAA/National Severe Storms Laboratory: Lightning impacts, avoidance, and weather-related research

NASA: Where lightning strikes

Moonraker Antenna Systems: Lightning at sea

West Virginia Lightning: Lightning formation illustrated with animated displays

Museum of Science, Boston: How lightning happens

USA Today: Lightning science by Jack Williams

Everest scrapes the stratosphere

Q: Mount Everest is so tall it actually touches what? Melissa, Kashmir, India

A: The stratosphere. Mount Everest pokes two-thirds of the way through the air of the Earth’s atmosphere to the ozone-producing stratosphere — 5.5 miles (8.7 km) up. Stratosphere air contains little water vapor or dust; only wispy cirrostratus clouds streak the distant sky. Storm clouds, however, can and certainly do form around the landmass of Everest.

The Himalaya Mountain maze from space, yellow arrow points to Mount Everest. Astronauts, orbiting at 5 mi/sec (8 km/sec), have seconds to find it. [NASA]

The mountain peak (29,035 feet) scrapes the jet stream. In the winter, the high-flying jet stream hurtles in from the north and batters Mount Everest with hurricane-force winds exceeding 177 mph (285 km/h).

Few Earthlings venture this high. Men struggled from 1921 on to scale the peak.

On the first expedition, A.F.R. Wollaston, the medical officer, saw a bearded vulture soaring over North Peak at about 25,000 feet. At 22,000 feet, a naturalist on the next expedition discovered Earth’s highest permanent residents. Some minute black spiders (Attid spiders) lurk in crevices among rocky debris. What they eat is a mystery. No plants or any visible sign of organic life lives this high.

Finally, in 1953, Edmund Hillary and Tenzing Norgay succeeded in climbing Earth’s highest mountain.

Further Surfing:

Panoramas: Turn slowly around and see the 360-degree top-of-the-world view from Mount Everest’s summit. Photos by Roderick Mackenzie

NASA: Find Mt. Everest in the maze of mountains

Expeditions: Fauna and flora on the mountain

Peakware World Mountain Encyclopedia: Mount Everest

(Answered Mar. 5, 2004)