“The work revolutionized the way we think of bird brains,” said Diana Reiss, a psychologist at Hunter College who works with dolphins and elephants. “That used to be a pejorative, but now we look at those brains – at least Alex’s – with some awe.” Other scientists, while praising the research, cautioned against characterizing Alex’s abilities as human. The parrot learned to communicate in basic expressions – but it did not show the sort of logic and ability to generalize that children acquire at an early age, they said. Alex showed surprising facility. For example, when shown a blue paper triangle, he could tell an experimenter what color the paper was, what shape it was, and – after touching it – what it was made of. Even up through last week, Alex was working with Pepperberg on compound words and hard-to-pronounce words. As she put him into his cage for the night last Thursday, she recalled, 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, Pepperberg said. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! He knew his colors and shapes, he learned more than 100 English words, and with his own brand of one-liners he established himself in TV shows, scientific reports, and news articles as perhaps the world’s most famous talking bird. But last week Alex, an African Gray parrot, died, apparently of natural causes, said Irene Pepperberg, a comparative psychologist at Brandeis University and Harvard who studied and worked with the parrot for most of his life and published reports of his progress in scientific journals. The parrot was 31. In 1977, when Pepperberg, then a doctoral student in chemistry at Harvard, bought Alex from a pet store, scientists had little expectation that any bird could learn to communicate with humans, as opposed to just mimicking words and sounds. Research in other birds had been not promising. But by using novel methods of teaching, Pepperberg prompted Alex to learn scores of words, which he could put into categories, and to count small numbers of items, as well as recognize colors and shapes.