This is where the case of the L'Aquila toads was different. Rachel Grant, a biologist from the Open University, was monitoring the toad colony as part of her PhD project. "It was very dramatic," she recalled. "It went from 96 toads to almost zero over three days."
Ms Grant published her observations in the Journal of Zoology. "After that, I was contacted by Nasa," she told BBC Nature.
Scientists at the US space agency had been studying the chemical changes that occur when rocks are under extreme stress. They wondered if these changes were linked to the mass exodus of the toads.
Their laboratory-based tests have now revealed, not only that these changes could be connected, but that the Earth's crust could directly affect the chemistry of the pond that the toads were living and breeding in at the time.
Nasa geophysicist Friedemann Freund showed that, when rocks were under very high levels of stress - for example by the "gargantuan tectonic forces" just before an earthquake, they release charged particles.
These charged particles can flow out into the surrounding rocks, explained Dr Freund. And when they arrive at the Earth's surface they react with the air - converting air molecules into charged particles known as ions.
Polistra was named after the original townsite of Manhattan (the one in Kansas). When I was growing up in Manhattan, I spent a lot of time exploring by foot, bike, and car. I discovered the ruins of an old mill along Wildcat Creek, and decided (inaccurately) that it was the remains of the original site of Polistra. Accurate or not, I've always liked the name, with its echoes of Poland (an under-appreciated friend of freedom) and stars. ==== The title icon is explained here. ==== Switchover: This 2007 entry marks a sharp change in worldview from neocon to pure populist. ===== The long illustrated story of Polistra's Dream is a time-travel fable, attempting to answer the dangerous revision of New Deal history propagated by Amity Shlaes. The Dream has 8 episodes, linked in a chain from the first. This entry explains the Shlaes connection.