In An Immense World - How Animal Senses Reveal the Hidden Realms Around Us, science writer Ed Yong takes the reader through a variety of species and their notable senses. These senses include: smell, taste, light, colour, pain, heat, contact, vibrations, sound, echoes and electric and magnetic fields.
Listening to the audiobook narrated by the author, interesting quirks of nature caught my attention along the way. One of those was the fact that the ears of owls are uniquely asymmetric. The left ear of an owl is higher than their right ear, enabling the bird to use the difference in timing and loudness to distinguish sounds in the vertical and horizontal.
When relating just how sensitive the sense of smell is in dogs, the author tells us:
"In past experiments they have been able to tell identical twins apart by smell. They can detect a single fingerprint that had been dabbed onto a microscope slide then left on a rooftop and exposed to the elements for a week. They could work out which direction a person had walked in after smelling just five footsteps. They have been trained to detect bombs, drugs, landmines, missing people, bodies, smuggled cash, truffles, invasive weeds, agricultural diseases, low blood sugar, bedbugs, oil pipeline leaks and tumours." Chapter 1 Leaking Sacks of Chemicals: Smells and TastesInsects can taste with their body parts and some have taste receptors on their wings enabling them to identify traces of food as they fly around.
In a chapter about bats and their ability to hunt prey with echo location, the author meets with a bunch of Lepidopterists at their lab. Entering the flight room of the bats, Yong can see a cloud of snow like substance hanging in the air that has come off the moths brought in for the bats to catch. If you've ever caught a moth or butterfly - or even cleaned up a dead one - you'll have noticed the powder or dust that comes off them after handling.
I was surprised to learn this substance is actually made up of tiny scales that serve an important function for moths and butterflies and apparently it's a common occupational hazard for Lepidopterists to become allergic to the scales due to overexposure.
"When not inflaming the airways of scientists, the scales protect the bodies of moths by absorbing the sound of a bats calls and muffling the resulting echoes. This acoustic armour is just one of several anti-bat defences." Chapter 9 A Silent World Shouts Back: EchoesVery interesting. An Immense World - How Animal Senses Reveal the Hidden Realms Around Us by Ed Yong was a detailed and thorough look at the senses of multiple species in depth and I'll admit my attention started to wander. The frequent references to a creature's umwelt* during the audiobook's 14+ hours of listening time become repetitive and I wished the author had used an alternate phrase from time to time.
An Immense World is recommended for those interested in biology, science, chemistry, physics, nature and the environment.
* I'd never heard of the world 'umwelt' and had to look it up, but it means 'the world as it is experienced by a particular organism.'
