Speaking of that, its behavior listed at some of the linked articles on the main site seems to closely resemble that of a 4 or 5 year old child (ignoring the guardian's writing style):

http://www.guardian.co.uk/science/grrlscientist/2012/dec/07/...

The first toy was a sound-activated squirt gun. This toy sprayed water on Pepper whenever he screamed. After an initial period of silent astonishment at his human companion's sheer ingenuity, Pepper tested the toy thoroughly and grew to love it. Of course, Pepper's shrieks were rewarded so he screamed more than ever, although now, his frustration was tempered with long moments of soggy, shrieking delight.

"He started using it as a bird bath", admits Mr Gray, who originally designed this particular toy to quiet Pepper. He added: but "then he'd scream just to be squirted."

Another parrot that was studied closely for its intelligence was Alex the Parrot. There was evidence it understood the concept of zero and could put together words to describe objects it hadn't seen before:

http://en.wikipedia.org/wiki/Alex_the_parrot

"Alex understood the turn-taking of communication and often the syntax used in language.[10] He called an apple a "banerry", which Pepperberg thought to be a combination of "banana" and "cherry", two fruits he was more familiar with.[14]"

Alex also had a tendency to turn the tables on the researches by giving incorrect answers when it knew the correct one as well:

Once, Alex was given several different colored blocks (two red, three blue, and four green—similar to the picture above). Pepperberg asked him, "What color three?" expecting him to say blue. However, as Alex had been asked this question before, he seemed to have become bored. He answered "five!" This kept occurring until Pepperberg said "Fine, what color five?" Alex replied "none". This suggests that parrots, like children, get bored. Sometimes, Alex purposely answered the questions incorrectly, despite knowing the correct answer.[15]

Though it's only self-anecdotal, I put some old peanuts out a while ago for some birds or squirrels to eat and noticed that a pair of Blue Jays were usually grabbing them. I started putting the peanuts in different locations and would observe how they would react. At first, they would look for them around their usual spot and then they would search around the yard until they discovered where they were located now.

I was going to take it a step further and cover one in some way (like with a paper cup) and another next to it exposed see if they would spot both of them. However, they stopped coming around one day and couldn't take my amateur experiment any further. They also were very observant to if you were watching them as well. At least several times they decided not to grab the peanuts that were closer to the house and where I was watching them through the window most likely because they detected me.

I can never get enough information on nearly any random topic and lately that's been extended to birds. The past few years that I have been studying birds more closely, I've realized that we underestimate the intelligence and cleverness of many of them despite being probably the most common animal we see in the wild on a daily basis.