Air Date: Week of February 21, 2020

The sulfur crested cockatoo using its left hand based on the orientation of its vision. (Photo: Simon Tout CC)

More than three quarters of humans are right handed, regardless of culture or where we live in the world. Scientists haven’t really figured out why our species has such a dominance for right handedness but they have found a similar preference in other species. BirdNote®’s Michael Stein reports.

Transcript

CURWOOD: It’s Living on Earth, I’m Steve Curwood.

[BIRDNOTE THEME]

CURWOOD: More than three quarters of humans are right handed, regardless of culture or where we live in the world. Scientists haven’t really figured out why our species has such a dominance for right handedness but they have found a similar preference in other species. BirdNote’s Michael Stein reports.

BirdNote®

Left Foot or Right? Handedness in Birds
Imagine you’re about to shake hands, but with a Sulphur-crested Cockatoo.

[Sulphur-crested Cockatoo calls, https://macaulaylibrary.org/asset/234725, 0.05-.07]

Should you offer your right hand or your left?

You should hold out your left hand. That’s because most Sulphur-crested Cockatoos are left-footed.

[Sulphur-crested Cockatoo calls, https://macaulaylibrary.org/asset/234725, 0.05-.07]

In complex tasks like manipulating a piece of fruit, these intelligent birds work intently with their feet. A parrot’s eyes are located on the sides of its head. So, if it wants to look at something -- say, a delicious piece of fruit -- it has got to cock its head one way or the other do it. And if it looks with its left eye, then uses its left foot.

Scientists call this handedness. That’s when one hand — or foot — is used consistently over the other for doing more complex tasks.

In a study of 16 Australian parrot species scientists found that about half were lefties, a third were righties, and a few were neither.

Handedness, once thought unique to humans, is also seen in chimps and gorillas — mostly righties — and orangutans — mostly lefties, as well as cats and kangaroos.

The evolution of handedness, for righties and lefties alike, improves skill and efficiency in complex tasks—for both parrots and for humans.

###
Written by Bob Sundstrom
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Recorded by V Powys ML234725.
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
Producer: John Kessler; Managing Producer: Jason Saul; Associate Producer: Ellen Blackstone
© 2019 Tune In to Nature.org February 2019/2020 Narrator: Michael Stein

ID# handedness-01-2019-02-07 handedness-01

CURWOOD: For pictures of these birds, fly on over to the Living On Earth website, loe.org.

 

Links

BBC Earth News | “Parrots Prefer Left Handedness”

Science Friday | “Do Other Animals Show Handedness?”

Listen on the BirdNote® Website