"Long before it's in the papers"
August 26, 2015


Parrot found able to “conclude by excluding”

Aug. 26, 2015
Courtesy of the University of Vienna
and World Science staff

Gof­fin cock­a­toos, a cu­ri­ous par­rot spe­cies, can choose the cor­rect an­swer in a task by rul­ing out wrong al­ter­na­tives, a study has found.

Re­search­ers from the Un­ivers­ity of Vi­en­na set out to de­vel­op a game that could test this abil­ity in dif­fer­ent spe­cies. De­vel­op­ing this game was not an easy puz­zle it­self.

A cockatoo pecks at a pic­ture on a touch screen. (Cour­tesy U. of Vien­na)

One of the prob­lems of pre­vi­ous stud­ies, they said, was to ex­clude the pos­si­bil­ity that an­i­mals chose a new an­swer, or stim­u­lus, just out of cu­ri­os­ity rath­er than by ex­clud­ing known wrong an­swers.

The re­search­ers turned to a tou­ch screen com­put­er to pre­s­ent the test ma­te­ri­al.

Gof­fin cock­a­toos are an In­do­ne­sian par­rot spe­cies al­ready prov­en to have re­mark­a­ble cog­ni­tive ca­pa­ci­ties and great cu­ri­os­ity—a trait pos­sibly en­hanced by liv­ing on is­lands with few preda­tors.

In the task, the Gof­fins had to learn to as­so­ci­ate a pic­ture with a re­ward that they would re­ceive right af­ter tou­ching the pic­ture. An­other, ac­com­pany­ing pic­ture would net no re­ward. 

Dur­ing the train­ing, the un­re­warded pic­ture oc­ca­sion­ally was re­placed by new, un­known pic­ture. Only once the birds re­liably chose the “good” pic­tures over the wrong or new ones were they tested for their in­fer­ence skills. This was meant to en­sure that the cock­a­toos wouldn’t choose new pic­tures just out of cu­ri­os­ity.

In the fol­low­ing tests, var­i­ous com­bina­t­ions of nov­el and known pic­tures, which could be re­warded or un­re­warded, were pre­s­ented. Their per­for­mance al­lowed the re­search­ers to tell apart oth­er strate­gies that the birds may have used. 

“More than half of our cock­a­toos choose their pic­tures in a way that clearly in­di­cates the abil­ity of in­fer by ex­clu­sion about re­warded stim­u­li. How­ev­er al­ter­na­tive strate­gies al­so play an im­por­tant role,” said Mark O’Hara of the uni­vers­ity, who de­vel­oped the task with col­leagues.

“Con­sid­er­ing the cock­a­toos’ ca­pa­ci­ties in pre­vi­ous tasks we ac­tu­ally ex­pected that they would show in­fer­ences by ex­clu­sion, but this was the first test if we could de­tect this abil­ity with our new task. That we could show this sort of rea­son­ing, to­geth­er with oth­er strate­gies… lets us hope that the meth­od will be ap­pli­ca­ble to many spe­cies and ul­ti­mately might help us to un­der­stand some­thing about the ev­o­lu­tion of this abil­ity,” he added.

The study is pub­lished in the re­search jour­nal PLoS One.

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Goffin cockatoos, a curious parrot species, can choose the correct answer in a task by ruling out wrong alternatives, a study has found. Researchers from the University of Vienna set out to develop a game that could test this ability in different species. Developing this game was not an easy puzzle itself. One of the problems of previous studies, they said, was to exclude the possibility that animals chose a new answer, or stimulus, just out of curiosity rather than by excluding known wrong answers. The researchers turned to a touch screen computer to present the test material. Goffin cockatoos are an Indonesian parrot species already proven to have remarkable cognitive capacities and great curiosity—a trait possibly enhanced by living on islands with few predators. In the task, the Goffins had to learn to associate a picture with a reward that they would receive right after touching the picture, whereas the picture next to it would lead to no reward. During the training, the unrewarded stimulus occasionally was replaced by new, unknown stimuli. Only once the individuals chose reliably the positive stimulus over the negative or novel ones they were tested for their inference skills. This procedure was meant to ensure that the cockatoos would not choose new pictures purely based on curiosity. In the following tests however, various combinations of novel and known pictures, which could be rewarded or unrewarded, were presented. Their performance allowed the researchers to tell apart other, strategies that may have used by the animals. “More than half of our cockatoos choose their pictures in a way that clearly indicates the ability of infer by exclusion about rewarded stimuli. However alternative strategies also play an important role,” said Mark O’Hara of the university, who developed the task with colleagues. “Considering the cockatoos’ capacities in previous tasks we actually expected that they would show inferences by exclusion, but this was the first test if we could detect this ability with our new task. That we could show this sort of reasoning, together with other strategies… lets us hope that the method will be applicable to many species and ultimately might help us to understand something about the evolution of this ability,” he added. The study is published in the research journal PLoS One.