Random Samples

Science  27 Jan 2006:
Vol. 311, Issue 5760, pp. 447

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  1. Overfishing Bad for Birds

    Juvenile marbled murrelet. CREDIT: RICH MACINTOSH

    The decline of marbled murrelets, seabirds that nest in old-growth forests, has been blamed on logging in the Pacific Northwest. Butit now appears the birds are also the victims of overfishing.

    Ben Becker, a marine ecologist at Point Reyes National Seashore, and Steven Beissinger of the University of California, Berkeley, compared the diets of murrelets in central California before and after the collapse in the 1940s of the Monterey Bay sardine fishery. Analyzing the feathers of living and preserved birds, they found from nitrogen and carbon-isotope measurements that contemporary birds are missing out on high-nutrient prey. Instead of dining on sardines and anchovies, the birds are forced to scrounge for krill and other creatures low on the food chain. “It takes about 80 krill to equal the energy value of a single sardine,” says Beissinger, whose study is in press at Conservation Biology. As a result, few of the birds have enough energy to raise young, he says, and even in the best of times, fewer than half the adults are trying to reproduce.

    “This is very credible work,” says Kim Nelson, a wildlife biologist at Oregon State University, Corvallis, who has found marbled murrelets to be a threatened population in the Northwest. Unfortunately, she says, the U.S. Fish and Wildlife Service is proposing to remove the birds from endangered status in Washington, Oregon, and California.

  2. Asian Science on the Move


    Asia is now close to spending one-third of all the money the world is devoting to R&D, according to the newly released UNESCO Science Report 2005. Of the world's gross expenditure on research and development (GERD) in 2002, about $2.8 trillion, Asia accounted for 31.5%, up from 27.9% in 1997. At the same time, North America's share fell from 38.2% to 37.0%, and Europe's from 28.8% to 27.3%. The Asian spurt is led by China, whose GERD went from 3.9% of the world total in 1997 to 8.7% in 2002. Recent UNESCO figures indicate that the proportion of China's gross domestic product devoted to R&D more than doubled in less than a decade, reaching 1.44% in 2004.

  3. Donner Party Postmortem


    The newly excavated remains of a campsite have provided fresh evidence of the survival struggle of the Donner party, 81 settlers who were trapped in the snow in the winter of 1846-'47 while crossing the Sierra Nevada. About half the party survived, and contemporaneous accounts tell of cannibalism at the end.

    One campsite, made by 59 travelers, was excavated more than a decade ago. Now, archaeologists have discovered the exact site 11 kilometers away where 22 others hunkered down. The research team, which described its findings earlier this month at a symposium held by the Society for Historical Archaeology in Sacramento, California, found no human burials or signs of cannibalism such as cooked human bones. (Uncooked bones would be eaten away by the acidic soil.) But signs of suffering were evident. Scattered around the campfire were nails from furniture and wagon parts that were burned. Bones from cattle, horses, and even the family dog had been chopped into small pieces and boiled to extract the last bits of fat. Pieces of china that had been unpacked from wagons show that the settlers were “being proper and … trying to normalize the situation,” says Julie Schablitsky, an archaeologist affiliated with the University of Oregon, Eugene, who co-led the excavations. “They were doing everything possible to avoid cannibalism.” Fragments of writing slates suggest that Tamsen Donner, a schoolteacher, may have given lessons during the months-long ordeal.

  4. Tale of a Raptor

    Berger with skull and eagle model. CREDIT: ROBERT KOENIG

    A South African paleoanthropologist says he has “conclusive proof” that the famous Taung child, a skull of a 3-1/2-year-old hominid who died 2 million years ago, was killed and eaten by an eagle. Discovered in South Africa in 1924, the skull provided the first fossil evidence that humans originated in Africa.

    Experts initially thought the child had been attacked by a big cat. In 1995, Lee Berger of the University of the Witwatersrand in Johannesburg and his colleague Ron Clarke pro-posed that the killer was a raptor. But critics said the skull markings were inconclusive and doubted that a bird could kill and carry off a child weighing at least 10 kg.

    Berger says he reexamined the Taung fossil last fall after reviewing a paper about eagle marks on monkey skulls. In a paper to appear in the American Journal of Physical Anthropology, he reports that he found two marks, including an incision in the eye orbit, that looked just like those on the monkeys. The monkey paper's author, Scott McGraw, an anthropologist at Ohio State University, Columbus, agrees that the marks seem “consistent with those we identified in the Ivory Coast monkeys, … all of whom were victims of eagles”—and some of whom weighed more than 13 kg. But at least one doubter remains. Ohio State anthropologist Jeffrey K. McKee says that the damage to the thin bone of the eye orbit could have occurred after death.