When i hire a new person, the first impression i have regarding their intelligence just from looking at their expression always proved to be true. Plus if you add some observing…
That approach leaves you wide open to unconscious bias and if you admit to hiring based on that, any reputable company will send you to HR so fast your head would spin.
Have you understood the issues raised here?
1) As a humans, we have a poor insight into avian intelligence. We try to judge them by human standards rather than recognising the way that they are adapted to figuring out how to survive as a bird. The simple actions of take off, flight and landing involve far more mental calculations than you or I are capable of making. A flighted bird is capable of changing direction and height mid-flight, swerving rapidly and almost hovering. Having that kind of control over one's body is an exceptional skill that no human can match.
2) Different species of bird are adapted to different environments. These different environments call for different strategies to survive. Survival may be found in establishing and nurturing connections in a large flock. Survival may be found in creating a solid pair-bond that will last for decades. Survival may be found in being able to fly for vast distances, alert to any potential food source. Survival may be found in learning how to exploit a new food source. Survival may be found in remembering and looking back. Survival may be found in anticipating, planning and looking forward.
A macaw, used to lush forests, could not survive in the arid deserts of Australia where cockatiels thrive.
Individuals may also different in terms of skills. A species needs the birds who seek out novelty to identify new foods, roosting sites and so on - but those birds are also more likely to die as a result of their curiosity. Flocks need the birds who are alert and wary to act as sentinels and keep the flock safe, but these birds may be too highly-strung to survive on their own. Flocks need the birds that are good communicators and friendly and easy-going to maintain the social connections within the flock. Are any of these birds stupid or less intelligent? Not at all - and the flock has room for different roles.
Intelligence - and identifying intelligence in humans, birds and other animals - is a vastly complicated subject and you would do well to be open-minded about it.