Dr. Nancy Merrick is a primary care and internal medicine doctor who has more on her mind than just the humans who pay her visits; Merrick also has the safety and welfare of the global chimpanzee population resting on her shoulders.

Speaking at a recent Ventura Sierra Club meeting in Ventura, Merrick presented Chimpanzees: In Their World, a talk on her work with Dr. Jane Goodall in Africa, to a crowd of around 150 people. Her recently published book, Among Chimpanzees: Field Notes From the Race to Save Our Chimpanzees, documents her experiences working with Goodall and her four-decade-long work to raise awareness of the chimpanzee population.

In 1972 as a student at Stanford, Merrick was given a seven-month scholarship to travel to Tanzania to join Goodall at Gombe Stream Research Center, where she had firsthand experiences with chimpanzees.

Merrick followed mother and infant chimps in Western Tanzania for upward of 10 hours at a time, an experience that Merrick says had her “almost rethink what it means to be human” as the chimpanzees used tools and interacted with each other.

“When I went to Africa in 1972 there were millions of chimps and we never worried about extinction,” says Merrick. “Today there are fewer than 300,000.”

The reason for the chimpanzee decline is multifaceted, says Merrick. The local human populations in Tanzania and in other areas where chimpanzees reside tend to be poor, making deforestation harder to control. Multinational corporations buy the land and hire locals to grow tobacco or oil palm trees in sensitive areas.

Rampant population growth spurs construction, meaning the acceleration of deforestation. Chimpanzees come into contact with humans more often and are susceptible to many of the same viruses. Polio and the Ebola virus have eradicated many chimp communities and Merrick cites the case of a chimpanzee that lost the use of its hands due to polio.

The chimpanzees now mostly reside in islands of forests cut off from other chimpanzee communities. For highly social animals like chimpanzees that often share members between communities, this means a decline in the number of communities and the degrading health of those that exist.

“Chimps are extinct in four countries of Africa now and they’re teetering on the edge of extinction in 10 others,” says Merrick. “Along with the bonobo, they are definitely considered to be man’s closest relative with only a 1 [percent] to 2 percent difference in our DNA.”

More than likely, she says, the orangutan which makes its habitat in Southeastern Asia where palm oil plantations are rampant will most likely be the first species to go extinct.

Merrick points to a small community of chimpanzees living outside of the national park in Uganda as an example of what is happening to the population as a whole.

“The entire area has been cut down by poor farmers just to get by,” says Merrick. “That forest has been largely cut down to grow tobacco. As soon as their forests are gone, they no longer have fruit trees and all of a sudden these chimps have to steal from farmers just to survive.”

Merrick says that things are looking up, however. Multinational corporations like Nestle and Unilever are listening to activists and sourcing palm oil from sustainable sources. Consumer interest in products that contain palm oil has given rise to more label-reading, smart-choice-making consumers in store aisles. Mobile apps designed specifically to tell a shopper which products make use of palm oil have risen in popularity as well.

“What’s been amazing to me is that consumers can have the kind of success that they’re having,” she said. “It’s truly a great example of how we can use our consumer interests to make a difference.”

Through the website chimpsaver.com, Merrick and her fellow activists give updates on the African chimp populations and ways in which to get involved.