Incredible Journeys: Exploring the Wonders of Animal Navigation
Hodder and Stoughton RRP $32.99
INCREDIBLE JOURNEYS is a dense and entertaining book that recounts how animals – from bacteria to baleen whales – use a staggering array of cues to find their way, often performing complex calculations to account for the seasons and our shifting geomagnetic landscape. Author David Barrie deftly weaves together interviews with scientists and exposition on aspects of earth science, illustrated with helpful diagrams.
Researchers studying animal navigation are a particularly patient lot. Barrie stayed with Australian scientists studying bogong moths (Agrotis infusa) for weeks; their experiments involved tethering the moths with threads to allow them to fly in a particular direction according to cues, without flying away.
It took three years of repeated experiments before the team realised the moths were using visual cues as well as the Earth’s magnetic field to set their course – navigating by the Milky Way.
Barrie is no stranger to navigation. At the age of 19 he crossed the Atlantic in a 10.6-metre yacht, and today he is a fellow of the Royal Institute of Navigation. In his capable hands, the book describes the two main ways animals (including humans) navigate.
The first, described in part one, is by following cues such as the sun, stars and polarised light. The tiny desert ant finds its way back to its nest using multiple tools: the sun as a compass, allowing for its changing azimuth, as well as a magnetic compass, polarised light, and even counting its steps like an odometer.
The second main method is by using a mental map, which offers great advantages in that it allows the construction of shortcuts that save valuable time and energy, or detours to avoid obstacles. Barrie recounts the development of the “cognitive map” idea and the latest evidence in birds and rats.
The final part of the book considers what the science of navigation means to us – especially in light of our now near-total reliance on GPS to find our way.
We have an idea of where we want to go but at a great cost, Barrie writes, likening our attachment to satellite-based navigation to a Faustian contract. We barely look at our surroundings anymore, and this is just another way that modern humans are disconnected with nature.
Incredible Journeys invites the reader to “learn again the language of the Earth”, and reconsider slavishly following the sat nav, or the blinking blue dot on our phones.