Science  19 Apr 2013:
Vol. 340, Issue 6130, pp. 256

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  1. Hares Wear Winter White, Even When It's Warm

    Deadly mismatch.

    Climate change could put color-changing hares out of sync with snow cover.


    For hares, fashion is life or death. Blending in with the environment is how they avoid being eaten: In winter, their coats turn white; in summer they are a mottled brown. This wardrobe switch starts at about the same time each spring and fall, a new study shows—which means that as the climate warms, by midcentury hares could be more than a month out of sync with snow cover.

    L. Scott Mills, a wildlife biologist at the University of Montana, Missoula, and his colleagues put radio tags on about 50 hares during the winters of 2010, 2011, and 2012. Every week, the team monitored how well each hare matched its background.

    Although one winter included 160 days of snow cover and another 190 days, the hares had trouble changing their coats to match, Mills and his colleagues report online this week in the Proceedings of the National Academy of Sciences. The results "provide a really compelling visual effect of climate change," says Daniel Blumstein, a behavioral ecologist at the University of California, Los Angeles.

  2. More Hints of Dark Matter?

    Physicists working with a supersensitive particle detector deep underground have spotted three events that could be particles of dark matter bumping into atomic nuclei. However, that's too few events to say anything definite, caution the researchers, who work with the Super Cryogenic Dark Matter Search (SuperCDMS) experiment that sits 713 meters down in the idled Soudan mine in northern Minnesota. "We certainly think it's interesting, but it doesn't rise to the level of discovery," says Blas Cabrera, a SuperCDMS team member from Stanford University in Palo Alto, California. The events could be "background" from ordinary particles, although the team estimates the chances of that at 0.2%.

    The hint, reported at a meeting of the American Physical Society in Denver, has others excited. "I'm thrilled!" says Rafael Lang of Purdue University in West Lafayette, Indiana, who works on the competing XENON Dark Matter Project. He notes that yet another experiment called CoGeNT in Soudan has reported similar, but more ambiguous signals. "This is how discoveries happen," Lang says, "they creep in and at some point you can't explain it away anymore." Look for results from XENON and other experiments within a year or two.