Schaller is recognized by many as the world's preeminent field biologist, studying wildlife throughout Africa, Asia and South America.

Schaller also, in 1964, recounted this epic two-year study in The Year of the Gorilla, which also provides a broader historical perspective on the efforts to save one of humankind's nearest relatives from the brink of extinction.

[13] The American zoologist Dian Fossey, with assistance from the National Geographic Society and Louis Leakey, followed Schaller's ground-breaking field research on mountain gorillas in the Virungas.

[2][6][17] In the fall of 1973, Schaller went to the remote Himalayan region of Dolpo, an area of Nepal occupied by people of the Tibetan culture and ethnicity.

[10] Schaller was there to study the Himalayan Bharal, (blue sheep), and possibly glimpse the elusive snow leopard, an animal rarely spotted in the wild.

[11] In 1980, as part of a cooperative project between the World Wildlife Fund (WWF) and China, Schaller carried out field research on the giant panda in the Wolong Nature Reserve in Sichuan Province.

Schaller also found evidence that pandas were originally carnivores, but underwent an evolutionary change to accommodate a diet of bamboo, which is difficult to digest, reducing competition with other animals for food.

[13] During his time in China, Schaller would hand out cards to wildlife hunters that read: "All beings tremble at punishment, to all, life is dear.

[22] While in Tibet, Schaller worked on researching the rare Tibetan antelope, or chiru, whose population declined due to trophy hunting for their exotic wool.

[24] Working with Tibetan authorities, and the Liz Claiborne and Art Ortenberg Foundation, Schaller helped protect the breeding and calving grounds of the chiru in the Kunlun mountains of Xinjiang Province.

[1][8][13] In danger due to their impressive spiral horns, which can measure up to 6 feet (1.8 m) in length, the sheep is sought out as a trophy by international hunters.

[1][5][8] Schaller's work in conservation has resulted in the protection of large stretches of area in the Amazon, Brazil, the Hindu Kush in Pakistan, and forests in Southeast Asia.

"[26][27] In a 2003 Denver Post article Schaller said that he is troubled that no Bigfoot remains have ever been uncovered, and no feces samples have been found to allow DNA testing.

They married in 1957 and Kay was an indispensable partner in life to her husband George for nearly seven decades where she assisted in fieldwork, edited and typed his manuscripts, and allowed him to pursue his passion for wildlife studies.