These parrots use their beaks as a 3rd limb to climb — and they're really good at it

It's hard to climb with two legs and no hands — unless you're a parrot.

Lovebirds, a type of parrot, have an incredible ability to use their beaks as a third limb while climbing, hoisting more than 70 per cent of their body weight using the muscles in their necks and heads, new research has found. 

It's an ability that's been observed across other species of parrots, too, and one that researcher Michael Granatosky calls "totally weird."

"For an animal to figure out odd uses of its different body parts, it's just crazy. It's really rare," Granatosky, an assistant professor of anatomy at the New York Institute of Technology, told As It Happens guest host Robyn Bresnahan. 

"This would be a [like] human pulling almost the equivalent of its entire body weight by its jaw and neck musculature."

Granatosky is one of the authors of a new study about the phenomenon, which was published Wednesday in the journal Proceedings of the Royal Society B.

Watch: A rosy-faced lovebird climbs in the lab:

In the animal kingdom, the distribution of limbs is usually even as a rule, says Granatosky.

It's extremely rare, he says, for an animal to break the mould and use another body part as a limb  — although it's not entirely unheard of. 

"We see it in things like kangaroos that use their tail as a fifth limb. Spider monkeys, they use their tails as a limb," he said. "But to our knowledge, it's the first example of an animal that actually uses its head to climb on these vertical surfaces."

The birds, he said, move almost like an inchworm, anchoring their legs, stretching their necks up to grab ahold of something, then pulling themselves up.

"Anyone who has a pet parrot, I think you can appreciate that they've seen this a million times. I have a parrot at home, and when he's tired of dealing with me, he just finds his way back to his cage, crawls up the wall and goes right back in," Granatosky said.

Every time I see my parrot want to get something or get to somewhere, it's just constantly astounding how he can do it- Michael Granatosky, New York Institute of Technology

"But trying to go into the scientific literature to find examples of this and understanding of this kind of movement, it just doesn't exist. So we're really happy that we're able to work on this."

Granatosky and his colleagues had six rosy-faced lovebirds climb a vertical surface equipped with sensors to measure how much force they were exerting, and in which directions.

They discovered the birds' neck and head musculature are incredibly strong — just as strong as their legs, in fact.  And the force generated by their beaks was equal to, or greater than, the proportional force exerted by the forelimbs of human and other primates when climbing.

It's perhaps not surprising when you consider that they can also use their powerful beaks to crack open nuts, Granatosky said.

"The amount of force that they use for biting into things is a lot more than they use for actual locomotion," he said. "Certainly in the lab, we have these scars to prove that all over our hands."

A possible tool for veterinarians 

Brian Speer, the director of the Medical Center for Birds in Oakley, Calif., said the study scientifically quantified what people have long observed about parrots, and could have implications for veterinary medicine.

"In some birds with chronic painful conditions (arthritis, articular gout of the feet and toes, etc.) you can see increased use of the maxillary [upper] beak to aid in movements, above and beyond what is normal — merely to aid their movements in the presence of pain or other disabilities," he said in an email.

So if a parrot starts using its beak in this way more often than usual, that could be used as "a means of assessing welfare, quality of life, and effectiveness of treatments being utilized."

So how did the birds evolve to be such good neck climbers?

"This is the big wide open question, actually, that we're still trying to investigate," Granatosky said. But his best guess is that they simply "figured it out."

After all, they're really smart.

"Parrots as a group, and I guess birds as a group in general, have always been portrayed as bird-brained, right? Not particularly intelligent. But when you actually look at the … brain anatomy of parrots, in particular, they rival primates for their intelligence on how they can figure things out," he said.

"Every time I see my parrot want to get something or get to somewhere, it's just constantly astounding how he can do it."

Written by Sheena Goodyear. Interview with Michael Granatosky produced by Leslie Amminson.