Koko gained public attention as the subject of two national geographic cover stories and, in 1985, the best-selling children's picture book, koko's kitten. Koko became the world's most famous Ò€¦ The gorilla foundation is best known for conducting the longest interspecies communication study in history (almost 5 decades) and the only one involving gorillas:

Koko, the western lowland gorilla that died in her sleep tuesday at age 46, was renowned for her emotional depth and ability to communicate in sign language.