Roaming a Myrtle green swath of forest in the Pearl of Africa, Maureen McCarthy attaches what looks like an oversized electric-yellow iPhone to a long stick and extends it skyward in a tiny clearing among a canopy of trees.
The device is a Global Positioning System (GPS) that the USC College Ph.D. student is using to record the location of a foraging party of chimpanzees in the Kasokwa Forest Reserve in Uganda.
McCarthy spent three months in the tropical rain forest this past summer tracking the ranging patterns of 16 chimps living in a small, long and narrow — roughly 1.5 square miles by 500 feet — patch of land cut off from main forest blocks such as Budongo. Small isolated populations of humans’ closest relative have developed in the area as a result of an expansion of sugarcane fields.
Forest clearing throughout Uganda for timber, charcoal and firewood has been rigorous for the past 200 years, particularly in the last half century. The riparian forests have been converted to cropland and the essentially trapped chimps face local extinction if females are not able to disperse to other communities.
McCarthy is a doctoral student in the College’s Integrative and Evolutionary Biology (IEB) graduate program. In her second year, she is conducting her dissertation research on the behavioral ecology of chimpanzees stranded in fragments of forest that have been carved up by agriculture. A USC College Doctoral Fellowship and the USC Jane Goodall Research Center covered the cost of her research trip.
Using the GPS, McCarthy is studying the ranging patterns of these chimps trying to survive in a limited space with nontraditional food supply. While their main food source used to be figs, they are now forced to eat sugarcane and human crop food, such as bananas, mangoes and papayas. Some of the extinction dangers they face are disease, genetic inbreeding, poaching and hunting, and severe injuries and death due to wire snares or jaw traps meant to capture small mammals such as bush pigs.
“I’m interested primarily in their conservation,” McCarthy said of the chimps she’s studying in Uganda. “I hope there are implications to my research. I hope to find something that will benefit humans living there as well as the chimps. But it’s too early to know.”
Back in Uganda, McCarthy watches the chimps — ranging from infants to approximately 30- year-old adults — munching on sugarcane. The summer trip was her second to Uganda. In 2007, while a graduate student at Central Washington University, she assisted a University of Oxford Ph.D. student researching chimpanzees there.
Through binoculars, she has witnessed many scenes. One rainy morning, she watched a slumbering mother and her baby cuddled in their tree nest. She observed a toddler chimp race up and down a tree branch, leap and tumble into his nest and repeat the stunt over and over.
“He was like a child jumping on the bed,” she said.
She observed the group’s alpha male named Komuntu (meaning “human” in Nyoro) sharing with other chimps the meat of a black and white colobus monkey he had just killed. She came across a mother chimp right after she had given birth, the baby’s umbilical cord still attached.
She waits until the chimps have left, then she stands in the spot where they were and records the location. Tracking the chimps on the GPS for about a year will enable her to among other things track what they are eating and measure their nutritional intake.
Her project is among the first tracking chimps’ ranging patterns within small patches of forest. There is also a possibility that the chimps have found a way to other fragments or to the nearby Budongo Forest. The broader impacts of the study in its early stages will help uncover the effects of forest fragmentation and guide conservation measures in western Uganda and elsewhere.
Conservationists have suggested that a solution to high conflict between villagers and the chimps may be translocation — moving the entire Kasokwa chimpanzee community to another forest. McCarthy questions that approach at this point in her research.
“Even if one moved to another location, it could be disastrous,” McCarthy said. “The chimps in the other locations would be very territorial. Any new chimp introduced could be injured or killed.”
McCarthy obtained the GPS unit from the College’s Spatial Sciences Institute (SSI), which provides technological support and education on geographic information systems (GIS) in disciplines across the university. She’s currently taking a course through the institute to learn more about how she can utilize her recorded data in her research.
A GPS unit, basically a radio receiver and a computer, measures the distance from where it is to each of several surrounding satellites.
“There’s a great deal of environmental research in which specific animals both alter and are altered by their environments,” said John Wilson, professor of geography in the College and institute director. “Scientists interested in studying and explaining these interactions look at how things are organized in both space and time.
“The GPS unit we loaned to Maureen helps her understand where the chimpanzees spend their time because the unit automatically records locations in a globally recognized and usable geographic referencing system. It also can record digital information regarding what they were doing at different places and times during the period they were observed.”
Once back at USC, the digital data collected with the GPS can be utilized with other data sets — map data, satellite imagery, etc. — to examine the relationships of interest. In McCarthy’s case, how the chimpanzees respond to human encroachment, forest deletion, different food supplies, among other things.
Craig Stanford, professor of anthropology and biological sciences, and co-director of the Goodall Center, is McCarthy’s adviser. He said GPS is becoming an essential tool for students conducting land use research.
“Maureen’s use of GPS to map the use of fragments is exciting because fragments are inherently hard to study, being scattered, unpredictable as to where the chimps will be,” Stanford said. “In the 21st century more and more chimp habitat is becoming fragmented. It’s essential that we know the effects on chimp societies.”