Birds like crows and parrot have demonstrate their cognitive prowess time and fourth dimension again . But despite being outstandingly intelligent , birds have small brains . A macaw , for good example , has a brain the size of it of a walnut tree . Now , investigator studying mind from 12 of mintage bring out that bird brains bear very large numbers of small , tightly - packed neurons . Ounce for ounce , birds have as many neurons in their brains as high priest . The findings are published inProceedings of the National Academy of Sciencesthis week .
Among their many cognitive feat , parrots and corvids ( crows and ravens ) have been love to make anduse tools , problem solve , recognizethemselves in mirrors , andplanfor their next needs . Additionally , songbirds are able of outspoken encyclopedism – something only a few species ( including humans ) have a capacity for , and parrots not only learn human words , they can habituate them to communicate with us . Yet the brain of a mutual raven is 15.4 grams on average , and that of the hyacinth macaw is 24.7 gm . Small brains are ask to have a low-spirited information - processing electrical capacity .
A team take by Pavel Nemec of Charles University in Prague wanted to liken neuron numbers across birds and mammal of like body size . They measured the phone number of neurons in the brains of 28 snort mintage : 11 parrot species , 13 vocal find out songbird species ( including six corvids ) , and four other birds ( an emu , barn owl , red junglefowl , and a pigeon ) . A few of these brains are pictured above .
" In designing brains , nature has two parameters it can play with : the size of it and number of neuron and the statistical distribution of nerve cell across different brain center , ” study cobalt - writer Suzana Herculano - Houzel of Vanderbilt University said in astatement . “ And in birds we find that nature has used both of them . " The team found that bird mentality have more nerve cell than mammal brains – and even primate brains – of standardised mass , and they have higher neuronic densities too . The brains of parrot and songbird species bear about twice as many neuron as primate brains of the same mass and two to four times as many as that of rodent brain . what is more , compared to mammals , a greater proportion of Bronx cheer nerve cell are locate in the prosencephalon , the area link with intelligent behaviour .
While the relationship between intelligence and number of neurons is n’t firmly lay down , these determination demonstrate that there ’s more than one fashion to design a brain . “ snort brainiac show that there are other ways to add together nerve cell : keep most neuron small and locally connect and only allow a small part to grow large enough to make the long connexion , ” Herculano - Houzel explicate . “ This keep the average size of it of the neurons down . ”
