Given that we now live in era of almost constant surveillance (never thought I’d write that in an offhand manner), and that Earth is apparently ensconced within a cocoon of satellites, I’m always surprised to learn just how much we don’t know about our home planet. For example, even though African elephants are the largest terrestrial animals on Earth, we haven’t the slightest idea how many of them are left. Population estimates range all the way from 250,000 to 690,000, but it’s difficult to find more accurate data since the last pan-African aerial survey was conducted in the 1970s. The matter assumes even greater importance in light of a new report published in this week’s Proceedings of the National Academy of Sciences. George Wittemyer and and his coauthors conducted a field survey of elephant carcasses in Samburu, Kenya, and determined that African elephants are now more threatened than ever. The authors explain that a growing demand for black-market ivory in China has fueled widespread illegal poaching in Africa. Conservationists are now sounding the alarm on behalf of elephants, but it’s difficult to initiate conservation efforts when you don’t even know how many elephants are left. In an effort to finally attain some concrete numbers, conservationists have initiated a year-long project known as the Great Elephant Census. Funded by Microsoft billionaire Paul Allen, the project will also count other savannah species, including giraffes and hippopotami. Team leaders expect to have the results tallied by this time next year. To learn more about the plight of African elephants, check out the links here, here, and here.