Using animals to explore the ‘rather wondrous’ sensory abilities of humans | CBC Radio

“Most scientists and neuroscientists nowadays would say we have upwards of 22 senses,” Higgins told CBC As It Happens host Carol Off.

Using 12 animals as case studies, Higgins honed in on 12 of those senses in her forthcoming book, Sentient: What Animals Reveal About Our Senses.

By focusing on the remarkable abilities of specific species, the animal kingdom can serve as “a mirror that we can hold up and get a clearer picture of ourselves,” Higgins explained. 

Desire’s in the air 

Take Europe’s giant peacock moth species, whose females are able to release pheromones, “which male moths can smell from up to three miles away,” Higgins said.

Smitten, the male moths stop what they are doing to trace the pheromones back to a willing mate.

“There is a big humdinger of a debate as to whether humans sense pheromones. I look at that and I playfully call the chapter the sense of desire,” she said.

Though pheromones may not be able to control our behaviour in the way they do for peacock moths, Higgins uses the species as a jumping-off point for a discussion on the way olfaction influences mate selection for humans.

Choosing a co-parent based on what you smell — however unconsciously — is “an evolutionary tactic that enables you to build immune diversity within your offspring, so that they’re going to be ruddy cheeked, healthy little babies,” she said with a laugh. 

Time and space

Trashline orbweavers, a species of spider found throughout the world, are the poster children for Higgins’s chapter on sensing time.

Scientists studying the orbweavers “noticed that these spiders were waking before sunrise every morning to rebuild their nests. They were using their body clock,” she said.

Not only that, the spiders are on an 18-and-a-half-hour cycle, so they’re “having to adjust all the time.”

“Scientists want to look at them to understand if they have some traits that enable us to cross time zones and not suffer jet lag,” Higgins said.

Another star species in Sentient is the bar-tailed godwit, whose epic migration across the Pacific Ocean from Alaska to New Zealand is the longest-known non-stop flight of any bird.

Birds like the godwits, Higgins says, have magnetoreception, meaning they can sense magnetic fields to guide their sense of direction.

Whether humans can do the same is unproven, she continued — but research is looking promising.

Higgins points to work being done at the California Institute of Technology that has unearthed “some really interesting and tantalizing evidence to suggest that we are able to sense changes in magnetic fields.”

A ‘happy message’ about human ability

Higgins, who was a zoology student of Richard Dawkins and who went on to make wildlife and science films, credits her love of the natural world to her mother.

“I spent my childhood rock-hopping and turning up stones in rock pools and prodding and poking and being curious,” she said.

With Sentient, Higgins hopes that readers are able to learn more about their own abilities, but also to embrace the connection they share with all living things.

“You’re related to your dog, but also that slice of lettuce you had at lunchtime,” she said with a chuckle.

“It’s important that we ourselves remember that we are rather wondrous,” she continued. “It’s a happy message.”

Interview produced by Kate Swoger. Story written by Kate McGillivray.