London, August 5 (ANI): A pair of British researchers have cast doubt on the suggestion that New Caledonian crows plan their actions ahead of time to achieve a goal.
Past studies have shown that the cunning birds can sculpt twigs into hooks and wield multiple tools in succession to obtain an otherwise unreachable snack, prompting some scientists to conclude that they plan their actions beforehand to achieve a goal.
Joanna Wimpenny and Alex Kacelnik, at the University of Oxford, tasked seven too-totting crows with snagging a snack to find out whether they are schemers.
The snack used for the study was a morsel of pig heart trapped down a clear tube.
To get this treat, the birds needed to use a short stick to ferret an intermediate stick out of a different tube, which they used to obtain a third stick, which was long enough to reach the food.
Four New Caledonian crows passed Kacelnik's test, but they had previously practised one part of the sequence: retrieving stick tools with their beaks and using the tool to get a treat, and even then they varied in the amount of attempts they took to complete the task.
Two birds that had never rehearsed the basic task struggled to complete even one step, while a third untrained bird learnt to extract food in a simpler task, after 21 failures.
Kacelnik said that the errors suggested that the crows understood some aspects of the test, but probably not the full complement of sequences required for success.
The researcher further pointed out that crows tended to swap smaller sticks for larger ones, but not always.
If the birds had formulated step-by-step plans, according to him, they would not have made such errors.
"The fact that an animal is statistically better than random should not be confused with the animal being perfect," New Scientist magazine quoted him as saying.
A research article describing the study has been published in the journal PLoS-ONE. (ANI)