Salad Days

Heart disease doesn’t just hit humans. It’s the leading killer among male zoo gorillas, and scientists want to know why. Obesity? Perhaps, but the term has yet to be defined for the primates. Diet? Likely, and Elena Hoellein Less of Cleveland Metroparks Zoo is trying to prove it. As part of a multi-zoo study, she’s been feeding her two gorillas, Bebac and Mokolo, a trial menu meant to mimic the largely vegetarian one eaten in the wild. Heavy on leafy greens, the new diet is also modeled after a heart-healthy human one, says Less. Judging by the 65 pounds each of her charges has shed so far, it’s nothing to take lightly. —Catherine Zuckerman

OLD MENU  Since 2008, 22 gorillas at five zoos—in Cleveland and Columbus, Ohio; Asheboro, North Carolina; Seattle; and Toronto—have been weaned off specially formulated biscuits (left). The edibles delivered all the right nutrients but also a starchy, caloric punch.

NEW MENU  The gorillas now munch on many pounds a day of slimming, fiber-rich produce—including endive, dandelion greens, romaine lettuce, and alfalfa hay.

PHOTOS (FROM LEFT): REBECCA HALE, NGM STAFF; CLEVELAND METROPARKS ZOO

*ESTIMATED FIGURES FOR DEPTH AND TEMPERATURE
SEAN MCNAUGHTON. ART: HERNÁN CAÑELLAS. SOURCE: RENEE C. WEBER, NASA

THE FIRE WITHIN  | When Apollo astronauts visited the moon, they drilled no deeper than ten feet. Yet the instruments they left behind are helping us learn even today about the inner life of our celestial neighbor. The latest look at seismic data from four decades ago confirms that deep inside this cold, dry satellite is a hot, liquid core.

"The molten core tells us a lot about the evolution of the moon,” says NASA’s Renee Weber, who studied readings dating from 1969 to 1977, only a quarter of which had been analyzed since the Apollo missions. The power of modern computers enabled Weber and her colleagues to examine the remainder, with a focus on deep moonquakes. Like the Earth, the moon has a center consisting of liquid and solid layers, the innermost being the hottest yet solid due to intense pressure. But whereas the Earth’s core is convecting—that is, dynamic, giving rise to plate tectonics, volcanic activity, and a magnetic field—the moon’s is thought to be stagnant.

The liquid present in the outer core suggests the moon may have been entirely molten when it formed 4.5 billion years ago, says Weber. “Even though the Earth and moon formed at similar times, the moon is smaller, so it has lost heat and energy faster.” At some point the lunar core may have convected as well. How do we know? Magnetic traces on surface samples brought back by the astronauts. —Luna Shyr

An inside look at the moon’s molten core

The moon’s crust is highly uneven due to meteoritic battering of the surface.

The lunar core is about 60 percent liquid by volume, according to a new analysis of Apollo-era seismic data.

Pint Size(s)

One-third empty or two-thirds full? The British Beer & Pub Association (BBPA) is optimistic that another serving-size option for draft pints will revive an industry whose market share is wobbling under the influence of wine and spirits.

British law has long dictated that pubs sell beer and cider only in an imperial pint (pictured), which is about 20 percent larger than a U.S. pint, or in glasses one-third or one-half that size. But this year Parliament is set to scrap several restrictions on weights and measures to encourage innovation. This would legalize a two-thirds pint—an amount some are calling a schooner based on a similar-size Australian pour. Brits drink some 23 million pints of beer a day, but sales have dropped 19 percent over the past six years, and 25 pubs close in an average week, says the BBPA’s Neil Williams. He thinks the traditional pint glass “is seen as very much a male preserve.” If the new size can win over women, the industry may find that less is more. —Amanda Fiegl

Bugging Out

The Salt Creek tiger beetle (below) is unlovely and obscure. It scuttles, six legged, through its two-year life span in a wetland near Lincoln, Nebraska. Not even its looming demise is novel. By last year all but about 200 adults had disappeared from Little Salt Creek—more victims of urban sprawl and habitat loss, though natural flooding dilutes the salt seeps that feed the marsh.

University of Nebraska entomologist Steve Spomer isn’t giving up on the lowly insect. He and a few others have rallied the city and state governments, area zoos, and the U.S. Fish and Wildlife Service to save it. The state has used lottery money to help preserve its habitat. And the bug is being bred in local labs. Why? Because no one knows its real value to the ecosystem. As Spomer says, “If the Salt Creek tiger beetle goes, what goes with it?” —Peter Gwin

PHOTOS: REBECCA HALE, NGM STAFF (LEFT); JOEL SARTORE

Spotting the Leopard Writer Rudyard Kipling imagined a leopard’s spots came from the fingertips of a human, to help it blend in with the jungle. William Allen of the University of Bristol took a digital approach to breaking the camouflage code of it and other Felidae members. After comparing photos of the cats with a mathematical model of pattern development on their flanks, Allen and colleagues concluded that the complexity of many coat patterns was related to habitat. Spotted cats are typical of closed environments like forests; plain-coated ones tend to inhabit open spaces. Behavior also plays a role. The more time a cat spends in trees and is active at night, for instance, the more elaborately marked its coat is likely to be. “In evolutionary time periods cats can change their patterning relatively easily,” says Allen. “Perhaps in the future we may marvel at striped leopards and spotted tigers.” —Erin Friar McDermott

A census of WILD TIGERS in India shows their numbers have risen 20 percent—from 1,411 to 1,706—since the last count, in 2007. • Two species of ANTARCTIC PENGUINS have declined in the past 30 years. Scientists believe krill loss is the cause. • The name ZHUCHENGTYRANNUS MAGNUS was bestowed on a T. rex-size dinosaur whose fossil was recently discovered in China. • University College London researchers suggest that POLITICAL BIASES are reflected in brain structures.

Is It a Spider or a Scorpion?

With eight legs like a spider and claws like a scorpion, pseudoscorpions come fearsomely equipped. Meet the newest addition to the few thousand known species: the Parobisium yosemite, so named for its home, California’s Yosemite National Park.

Venomous? Yes. But humans have nothing to fear. The arachnid’s claws aren’t even big enough to penetrate our skin, says James Cokendolpher, a research scientist at the Museum of Texas Tech University who helped document the species. Like many other cave-dwelling pseudoscorpions, this beast could fit on a fingernail—fully stretched, it’s about half an inch long. Slender hairs help it sense air movements, and chemical receptors on the tips of its legs and pincers help it identify any creatures it encounters. In a cave’s rocky rubble, unsuspecting tiny spiders and soft-bodied insects would translate into a tasty meal. —TP

A Radiant Shell Green doesn’t always mean go. In the case of the marine snail Hinea brasiliana, flashing green sends a clear signal to crabs and other predators: Stop. This resident of Australia’s rocky shores isn’t the only bioluminescent snail, but its shell is one of a kind, says Dimitri Deheyn of the Scripps Institution of Oceanography who co-authored a report on the findings late last year. Other snails have transparent shells or body parts that glow when protruding, but not this one. Its opaque yellow shell scatters green light (pictured, in study simulation) produced by tightly packed cells on the snail’s body. Deheyn believes it may be the shell’s specific crystalline and protein structure that enables it to spread the light so effectively. So when predators come knocking, the snail’s entire surface flashes like an alarm system—possibly even temporarily blinding some nocturnal intruders. —Thomas Pierce