As for intelligent mammals/animals...
The parrot isn't the only animal that is capable of mimicking human speech and learning by its' usage.
The Mynah bird does the same thing, as well as cockatiels, and a few others.

But who says that vocalizing is the ultimate arbiter of intelligence? For years, primates (primarily chimpazees,
but big apes as well) have been trained in the use of sign language, and more recently in the use of symbols
in communications with humans. The studies have found that they are capable not only of communicating
by the base use of these methods, in addtion they can communicate abstract ideas! This was
seemingly a natural progression for the scientists directly involved with the study. But for behavioural
scientists, child psychologists and the like, the findings were troubling: up until now, it was assumed that
humans, as a species, are the only beings on this rock who are truly sentient. Hmmm... by what criteria?

As advanced as our species is, and as objective as science can be, there remains a slight problem-
we still tend to be conceited to the point that sentience requires a "soul", walking upright, self-awareness,
and so on. It's the same neighbourhood of the judeo/christian belief that not only are we at the center of
the universe, we're the only ones in it.

Awfully arrogant of us, don't you think?
good post BTW, general philosophical questions are vastly entertaining, Thanks!

Zaddikim