I just read on CNN about a remarkable African grey parrot named Alex, who unfortunately has suddenly died. Parrots are well-known for their ability to reproduce human speech, but are widely considered to have no comprehension of the sounds they are copying. This is in contrast to animals such as chimpanzees and dolphins who have considerable intelligence but lack the physical apparatus (such as a voice box) to produce sounds resembling human speech. However, as the CNN article describes,
Alex’s advanced language and recognition skills revolutionized the understanding of the avian brain. After [animal psychologist Irene] Pepperberg bought Alex from an animal shop in 1973, the parrot learned enough English to identify 50 objects, seven colors and five shapes. He could count up to six, including zero, was able to express desires, including his frustration with the repetitive research.
Although one should always remain skeptical—could this be a complicated set of conditioned responses?—my cursory perusal suggest that Alex did possess some understanding of these concepts. His achievements are quite impressive and well beyond what most people would expect birds capable of doing. It’s a shame this remarkable bird has been lost.
For more information, see Wikipedia, Nature News, the Scientific American blog, or a 2004 Scientific American article (PDF) describing Alex. You can also watch video of Alex as part of the Scientific American Frontiers program on PBS (“Entertaining Parrots”, 2001).