The case of the talking parrot
1. How are birds able to speak?
As a rule, as the basic intelligence of birds is extremely limited (i.e. limited to fulfilling its basic instincts of hunger, sleep, sex and fear), it is impossible for birds to achieve the feat of talking and acquiring an extensive vocabulary. The ability to speak in birds is either because it is affected or possessed by a ghost (demon, devil, negative energy, etc.) or because the bird is a devolved human being. That means it was a human being in its past life.
A human being can be devolved to be born into a lower species either because of his own wish or if he has excess demerits or cursed by a spiritually evolved person. In fact Spiritual research has revealed that 30% of animals are devolved humans.
2. Why would a spiritually evolved human being wish to take birth in a lower species?
A spiritually evolved being can opt to take birth in the animal or bird species out of his own free will to pursue his spiritual practice undisturbed by the distractions faced in a human birth. It is possible for spiritually evolved beings to carry on spiritual practice even when in the animal or bird species because 98% spiritual practice is subtle and internal to the person, i.e. not in terms of any tangible actions. When a spiritually evolved being takes birth in a lower species, it is up to him to also decide when to end that existence.
A person could also be born into a lower species as a result of a curse or as punishment for his intense demerits.