Alex the Parrot dies in research lab

Before Pepperberg's work with Alex, it was widely believed in the scientific community that birds were not intelligent and could only use words by mimicking, but Alex's accomplishments indicated that birds may be able to reason on a basic level and use words creatively.[4] Pepperberg wrote that Alex's intelligence was on par with that of dolphins and great apes.[5] She also reported that Alex had the intelligence of a five-year-old human[3] and had not reached his full potential by the time he died.[6] She said that the bird had the emotional level of a human two-year-old at the time of his death.[7]

Like parrots can, he also picked up one-liners from hanging around
the lab, like “calm down,” and “good morning.” He could express
frustration, or apparent boredom, and his cognitive and language skills
appeared to be about as competent as those in trained primates. His
accomplishments have also inspired further work with African Grey
parrots; two others, named Griffin and Arthur, are a part of Dr.
Pepperberg’s continuing research program.

Even up through last
week, Alex was working with Dr. Pepperberg on compound words and
hard-to-pronounce words. As she put him into his cage for the night
last Thursday, Dr. Pepperberg said, Alex looked at her and said: “You
be good, see you tomorrow. I love you.”

He was found dead in his cage the next morning, and was determined to have died late Thursday night.