Recent research reported by Dr Culum Brown of Macquarie University in Australia showed that some species of parrot such as the sulphur-crested cockatoo were entirely left-handed while others, including the king parrot, were mainly right-handed. The majority of parrots, including the budgie, galah and rainbow lorikeet - are ambidextrous.
''This is probably the first time we see some kind of mechanism trying to explain how handedness came about in the first place,'' Dr Brown said. ''It's clearly linked to brain lateralisation. So the brain lateralisation determines eye lateralisation, which determines hand preferences.''
There have been lots of reports over the years about various animals showing hand preference and here is a brief summary:
- Psychologists from Queen's University Belfast, who as part of their research played with 42 pet cats for weeks on end. They found that females are 'right-handed' while toms favour the left.
- Dogs are the same - until they are spayed or neutered, when the difference disappears, suggesting hormones play a role in left or right-handedness.
- Dogs wag their tails to the right when relaxed and to the left when agitated.
- Toads are mostly right-handed and pounce more quickly on morsels of food that enter their line of vision from their right.
- Fish will have a preference to left or right when they dodge a predator - this is likely to allow them to use a specific eye and side of the brain to deal with the threat. To test it out, place an unfamiliar object in the centre of your fish tank and watch which way your pet swims round it.
- Humpback whales prefer to use the right side of their jaws to scape up sand eels from the ocean floor.
- There has been a long-running Internet Meme that all polar bears are left-handed but we cannot find any scientific evidence to support it. In fact, one study of injury patterns in polar bear forelimbs found injuries to the right forelimb to be more frequent than those to the left, suggesting, perhaps, right-handedness.
If you come across any other reports on animals that are left-sided or disagree with any of those above, please
add a comment to this article.
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https://veggierevolution.blogspot.ca/2011/04/orangutans-are-lefties-chimps-and
Parrots tend to be "left handed," study finds
SYDNEY | Thu Feb 3, 2011 1:44pm EST
SYDNEY (Reuters) - Parrots, like humans, choose to use one side of their body more than the other, with more of them left handed -- or, more precisely, left footed than anything else.
Some species even try out both before deciding on one side.
Australian researchers found that virtually all the parrots they studied prefer to use either their left eye and left foot, or right eye and right foot.
"Basically, you get this very close relationship with the eye that they use to view the object and then the hand that they use to grasp it, and it's very consistent across all the species except a couple," said Calum Brown, a senior lecturer at Macquarie University in Sydney, who led the study.
"In some species, they're so strongly right or left handed at the species level that there's effectively no variation."
In the study, published in "Biological Letters," Brown and his colleagues studied roughly 320 parrots from 16 different Australian species to see which eye they used to view potential foods.
Ultimately, they found that roughly 47 percent were left handed, 33 percent right handed, and the remainder ambidextrous.
In addition, in some cases young birds appeared to experiment with both sides before finally settling on one.
"With Sulphur-crested cockatoos -- every single individual we've seen is left-handed. But when you see the juveniles which have just fledged, they're experimenting with both hands, all the time," Brown said.
"They eventually settle on using their left hands."
The idea of handedness in humans is tied to the use of one hemisphere of the brain over another, known as "lateralization." In the case of the parrots, this appeared to be an advantage regardless of whether the left or the right side dominated.
"It's quite obvious that in terms of direct foraging, as well as more complicated problem-solving situations, that if you're very strongly lateralized, irrespective of whether you're right or left handed, you tend to be better at this sort of task," Brown said.
He added that lateralization allowed much more efficiency, the way a computer with two processors can do two things simultaneously and effectively multi-task.
"We think that's possibly what's going on with parrots," he said.
(Reporting by Elaine Lies; editing by Sanjeev Miglani)
https://www.reuters.com/article/2011/02/03/us-parrots-hands-idUSTRE71277420110203
It is a known phenomenon that in some lobsters are born lefties.
Being somewhat ambidextrous, I started cutting them the way they laid.
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