Some of the chimpanzees were rejected pets. Others were captured in the wild. All of them were taken in the mid-1970s to a research laboratory in Liberia, where for decades they were infected with diseases, and their blood was drawn and tested for research that helped lead to a hepatitis B vaccine and safer blood transfusions for humans.
The New York Blood Center, a nonprofit that ran the lab, ended its research in Liberia in 2005 and retired the chimps to a collection of uninhabited mangrove islands in a river. For nearly a decade, the center supplied the animals with food and clean water, which aren’t available on the islands. Then, in 2015, as the impoverished nation staggered through an Ebola epidemic, the charity withdrew funding, saying the chimps were now the government’s responsibility.