BIRDS CAN RECOGNIZE PEOPLE'S FACES AND KNOW THEIR VOICES
Science Daily, June 22, 2012

New research suggests that some birds may know who their human friends are, as they are able to recognize people's faces and differentiate between human voices.

more at:
http://www.sciencedaily.com/releases/2012/06/120622163056.htm

RAVENS REMEMBER RELATIONSHIPS THEY HAD WITH OTHERS
Science Daily, April 19, 2012

In daily life we remember faces and voices of several known individuals. Similarly, mammals have been shown to remember calls and faces of known individuals after a number of years.

more at:
http://www.sciencedaily.com/releases/2012/04/120419132558.htm