True, this ability is limited to determining the correct length of tool, because in experiments only one parrot is able to make a device that is quite narrow which can penetrate the hole behind the bowl.
In a study published in the PLOS One scientific journal, six cockadopheid parrots were supposed to be captured in a glass box. Each bird is given a sheet of cardboard, but the cake is placed 4 to 16 centimeters from the opening in the glass box.
In general, all the abilities of parrots crawling along the cardboard line are desired to overcome them.
"Parrots are cut from the desired length of cardboard strips using the maxilla and lower jaw as scissors, or folded to the desired length and appear with a funnel. The subjects also draw their cardboard pieces, which turn out to be food pieces, but return to them when the food placed in the distance, "the researchers wrote.
If in the first attempt the tool was too short, the birds deliberately made their second teeth longer. Researchers think this is a strategy to avoid risk.
True, when the device is narrowed, the parrot has a problem. Only one bird is able to make its gear quite narrow when its opening is smaller.
In the future scientists plan to use other ingredients to see if birds are able to overcome other problems.