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December 15, 2015

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Parrots seen using pebble-tools in new way

Dec. 16, 2015
Courtesy of the University of York
and World Science staff

Cap­tive par­rots of a spe­cies known as Great­er Va­sa have been doc­u­mented for the first time us­ing tools—and do­ing so in ways nev­er re­ported among oth­er an­i­mals, sci­en­tists say.

The birds used small peb­bles or date pits to grind cal­ci­um pow­der from sea­shells, or to break off bits of shell to swal­low, ac­cord­ing to the new find­ings. That’s the first ev­i­dence of a non­hu­man us­ing tools for grind­ing, said the sci­en­tists. 

A Greater Vasa Parrot in Madagascar. Cap­tive par­rots of the spe­cies (scientific name Coracopsis vasa) have been doc­u­mented for the first time us­ing tools and do­ing so in ways nev­er re­ported among oth­er non-hu­man an­i­mals. (Im­age cour­tesy of Snow­man­radio)


The birds al­so some­times share the tools, which is rare, they added, al­though at oth­er times they just steal them from each oth­er.

Re­search­ers in the De­part­ment of Psy­chol­o­gy at the Un­ivers­ity of York in the U.K. ob­served the be­hav­iors among 10 cap­tive par­rots from the spe­cies, na­tive to Mad­a­gas­car and near­by is­lands.

“Whether these birds al­so use tools in the wild re­mains to be ex­plored,” said Megan Lam­bert, a doc­tor­al stu­dent in York’s De­part­ment of Psy­chol­o­gy and lead au­thor of a re­port on the find­ings pub­lished in the jour­nal Bi­ol­o­gy Let­ters.

“The use of tools by non­hu­man an­i­mals re­mains an ex­ceed­ingly rare phe­nomenon,” she added. “These ob­serva­t­ions pro­vide new in­sights in­to the tool-us­ing ca­pa­bil­i­ties of par­rots and give rise to fur­ther ques­tions as to why this spe­cies uses tools.

“Tool use could re­flect an in­nate pre­dis­po­si­tion in the par­rots, or it could be the re­sult of in­di­vid­ual tri­al and er­ror learn­ing or some form of so­cial learn­ing.”

They posted a YouTube vi­deo show­ing the var­i­ous tool uses and re­lat­ed be­hav­iors, with some of the more amus­ing sec­tions be­ing en­ti­tled “tol­er­ated theft” and “protested theft.”

Ob­serv­ing and film­ing the par­rots from March to Oc­to­ber of this year, re­search­ers doc­u­mented their in­ter­ac­tions with cock­le shells on the floor of their aviary. Shells are a source of cal­ci­um for birds. Five out of ten birds were doc­u­mented us­ing tools, plac­ing ei­ther peb­bles or date pits in­side shells to grind against the shell, or us­ing them as a wedge to break apart the sea­shell.

In­ter­est in the shells was great­est from March to mid-April, just be­fore the breed­ing sea­son; this may be due to cal­ci­um sup­ple­menta­t­ion be­ing crit­i­cal for egg-laying, the in­ves­ti­ga­tors said.

Re­search­ers were thus sur­prised at first to find that the great­est in­ter­est in shells came from males, not fe­males. A pos­si­ble ex­plana­t­ion emerged, though: the males were al­so seen feed­ing fe­males by re­gur­gi­tat­ing—a com­mon behavior—be­fore cop­u­lat­ing with them. This might pass on the cal­ci­um ben­e­fits to the fe­males, the re­search­ers pro­posed.


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Captive parrots of a species known as greater vasa have been documented for the first time using tools—and doing so in ways never reported among other animals, scientists say. The birds used small pebbles or date pits to grind calcium powder from seashells, or to break off bits of shell to swallow, according to the new findings. That’s the first evidence of a nonhuman using tools for grinding, said the scientists. The birds also sometimes share the tools, which is rare, they added, although at other times they just steal them from each other. Researchers in the Department of Psychology at the University of York in the U.K. observed the behaviors among 10 captive parrots from the species, native to Madagascar and nearby islands. “Whether these birds also use tools in the wild remains to be explored,” said Megan Lambert, a doctoral student in York’s Department of Psychology and lead author of a report on the findings published in the journal Biology Letters. “The use of tools by nonhuman animals remains an exceedingly rare phenomenon,” she added. “These observations provide new insights into the tool-using capabilities of parrots and give rise to further questions as to why this species uses tools. “Tool use could reflect an innate predisposition in the parrots, or it could be the result of individual trial and error learning or some form of social learning.” They posted a YouTube video showing the various tool uses and related behaviors, with some of the more amusing sections being entitled “tolerated theft” and “protested theft.” Observing and filming the parrots from March to October of this year, researchers documented their interactions with cockle shells on the floor of their aviary. Shells are a source of calcium for birds. Five out of ten birds were documented using tools, placing either pebbles or date pits inside shells to grind against the shell, or using them as a wedge to break apart the seashell. Interest in the shells was greatest from March to mid-April, just before the breeding season; this may be due to calcium supplementation being critical for egg-laying, the investigators said. Researchers were thus surprised at first to find that the greatest interest in shells came from males, not females. A possible explanation emerged, though: the males were also seen feeding females by regurgitating—a common behavior—before copulating with them. This might pass on the calcium benefits to the females, the researchers proposed.