The word
Bookends
Bat walking
Grounded thinking Human Impacts on Amazonia edited by Darrell Addison Posey and Michael J. Balick, Columbia University Press, £48/$74.50, ISBN 0231105886 Reviewed by Adrian Barnett
DIETMAR NILL/FOTONATURA/MINDEN
THE scene: a pond on a common in south London, long past 10 pm. The players: a group of bat enthusiasts and their guide, squinting into the darkness. “There’s one! Quick, tune to 21 kilohertz,” someone cries. The enthusiasts tune their detectors, which pick up the high-frequency noises and convert them into “smacks”, “tocks”, “ticks”, “chipchops” and “warbles” that people can hear. The bats come to this pond to drink and hunt insects. The humans come to marvel at these creatures of the night. Welcome to bat walking, the latest global nature-watching craze. Where there are bats, you’ll likely find a batwalking group – and many of them are oversubscribed (see www.bats. org.uk and www.batcon.org for local details). With numbers of bats worldwide in decline, conservationists are keen to build on this enthusiasm. Next Saturday (26 August) is European Bat Night, when conservationists in some 30 countries will try to raise awareness of the 45 species of bat that live in Europe through lectures, exhibitions – and bat walks (see www. eurobats.org). Why all the excitement? People seem to have cottoned on to the fact that bats are strange and fascinating creatures. They are the only flying mammal: their formal name, Chiroptera, comes from the Greek for “hand wing”, as the open wing resembles an outspread hand but with a membrane between the fingers that also links wing to body. Their sophisticated high-frequency
“More promising in the horror stakes are the two bat species that eat other bats” echolocation system makes bats formidable night flyers and hunters. They use the echoes from the sounds they make to create “audio maps” of space, to distinguish objects and find prey. And bats are voracious: a single animal can devour up to 1000 mosquitoes an hour. Bats also hold a more sinister attraction. They have long been associated in folk tales with foreboding and vampires, and to symbolise ghosts, death and disease. Yet contrary to popular opinion, most are not bloodsuckers, preferring insects or the juices
of fruits. Of the 1100 bat species worldwide, only three – all of them of the leaf-nosed family of central and South America (Phyllostomidae) – drink blood or prey on vertebrates. More promising in the horror stakes are the two species that eat other bats: the spectral bat, also of the Americas, and Australia’s ghost bat. Bats can also have a genuinely deadly side, at least in some parts of the world. Their mobility and their evolutionary development alongside humans together make them natural vectors for viruses that can cause diseases such as rabies and West Nile fever. You could hardly describe bat walking as dicing with death though, even if the few people in the US who die each year from rabies usually pick up the disease through being bitten by bats. ●
No. 1405 Richard England
the sum of the three integers must be a 4-digit number that consists of four different digits and is itself divisible by each of its four digits. Please submit the three integers.
Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to enigma@ newscientist.com (include your postal address). The winner of Enigma 1399 is J. Jamieson of Marlow, Buckinghamshire, UK.
FIND a 2-digit integer, a 3-digit integer and a 4-digit integer that between them use all the digits 1-9 in such a way that each integer is divisible by each of its digits; in addition
£15 will be awarded to the sender of the first correct answer opened on Wednesday 20 September. The Editor’s decision is final. Please send entries to Enigma 1405, New
Answer to 1399 A row of numbers 1) Frances won 2) Frances won 106 games, Matthew won none, and there were 84 draws.
Star-struck The Starry Messenger: Visions of the universe Exhibition at Compton Verney, Warwickshire, UK, until 10 September 2006 (www.comptonverney.org.uk) Reviewed by Colin Martin
48 | NewScientist | 19 August 2006
FITZWILLIAM MUSUEM/BRIDGEMAN ART LIBRARY
Enigma Digitally divided sum
AN ECLECTIC range of anthropologists, botanists and economists present what we know about traditional Amazonian ecological knowledge, and how it is crucial for conservation. The 20 accessible chapters meld together academic studies with pragmatic assessment and include discussions on the history of indigenous peoples’ contact with Europeans, European perceptions of “the tropics”, biopiracy and traditional life in the Amazonian rainforests and savannahs. The overall message: “short-term capitalism does not work here”.
TAKING its title from Galileo’s book The Starry Messenger, this perfectly curated exhibition explores our fascination with the universe, and how it has inspired scientific investigation and artistic imagination since the early 1600s. Artworks including an etching by William Blake are juxtaposed with 20th-century sci-fi comics and astronomical books and artefacts, conjuring up a lively interplay between science and art in the transmission and exploration of ideas about heavenly space.
www.newscientist.com