There are other intelligent species throughout the world but none of them can quite compete with the human being. We are capable of speech, which some believe is the only true way of gauging intelligence. We have the ability to articulate and create while expanding into territory that did not start off as our own. Some scientists even believe that the only reason we are superior in any fashion is because of our opposable thumbs.
I think out greatest redeeming qualities are our curiosity and need for knowledge. The downside to those qualities is the short-sightedness we often display. In our rush to explore and conquer we pay little attention to the intended or unintended consequences to our actions. Yes, there is destruction, betrayal, and arrogance to be found in other species throughout the hemispheres but none so much as what humankind has subjected this planet to.
I think that intelligence can be measured by actions and sometimes we just don’t rate. The human body is this amazing machine that is capable of unbelievable feats powered by the brain that can process more data in seconds than the most powerful computer ever created. However, we are also the subjects of our own premeditated destruction.
Through thousands of years of evolution the human race will face extinction not at the hands of others, as so many species have, but those of our own.