Does this parrot know nothing?

We know about zero, does this parrot?

Researchers explore whether parrot has concept of zero - www.world-science.net
Has a parrot has developed a numerical concept that mathematicians failed to grasp for centuries: zero.

Researchers explore whether parrot has concept of zero - www.world-science.net
Has a parrot has developed a numerical concept that mathematicians failed to grasp for centuries: zero.