The animal depicted on this black-and-white picture postcard is an emu. The San Diego Zoo is in Balboa Park, San Diego, California. This is a Real Photo postcard (RPPC) made with Azo photo paper (as evidenced in the stampbox on the back of this card). The Real Photo process allowed photographers to take a "snapshot" and have it finished at a photo shop that printed it out on postcard backing for mailing. This type of Azo papers was made from 1926 to the 1940's (the first stable-emulsion photo paper).