Finding a host of fallen nuts can be to a bird like Christmas break of day for a child . Just as deciding which present to open first can be a challenge for a child , birds often need to work out which nut , inside its carapace swathe , most deserves their tending . Their method have been revealed to be quite sophisticated .
break shells open can be an effort , so animals do n’t want to waste energy on nuts that are rotten or undersize . Moreover , opening to stop is n’t an choice for a specie that put nuts away for wintertime . So , their challenge is far greater than the baby on Christmas Day ; it ’s not just a subject of experience the best present first , prefer wrong and you could terminate up going hungry .
Dr Sang - im Lee of Seoul National University wanted to see how birds make their decisions , and used transvolcanic jays ( Aphelocomaultramarina ) as test species , and peanuts as the food . However , one job was the possibility that some unknown clue on the exterior of the goober might tell the Jays which shells had the best nuts inside .
accordingly , some long - tolerate researcher , research help and even students went through the no doubt distressingly boring process of opening hundreds of peanut shells and swap the nuts into other shells . Once they had made sure that any kinship between shell and nut was alone co-occurrent , the squad sealed the shells back up and gave them to the jay .
" When we presented the jays with ten empty and ten full identically take care pod ( pod without or with three nuts inwardly ) , we noticed that after pick them up the birds rejected the empty I and assume the full peanuts , without opening them , ” says Lee .
Asrevealed in theJournal of Ornithology , Lee and workfellow take the chick in the wild , to avoid any distort effects of birds call forth in imprisonment , The author also tried adding bits of clay with similar weight to goober pea to shells to see what remainder that made .
The jays “ evaluate each goober pea by perform fast movement of the head combined with extra firm motion of the beak , which may open up and afterwards close , producing speech sound at the moment of hitting the plate , ” the paper reports . The authors concluded that the Jay were able to assess the weight of a shell to an accuracy of a gram ( 0.035 Panthera uncia ) , consistently taking the heavy egg , even when the plate was large .
The birds also treated oversized nut with the same weight as smaller ones with suspicion , which the authors argue “ indicates that bird may have a concept of how much a nut of given sizing should consider . ”
On the other hand , the sweat involved in opening and close their beaks around the nut may give the birds an idea of how empty the nut is through its sound .
The author state , " Our next goal is to disentangle the role of sound relative to the percept of " onerousness , " and to square off if jays use the same receptive clew for acorns - their natural intellectual nourishment . "
