Chimpanzee Personalities

ChimpanzeeA study published in the American Journal of Primatology this month revealed new information about chimpanzee personality traits. The five defining personality dimensions in chimps are: reactivity, dominance, openness, extroversion and agreeableness.

Researchers collected behavioral data for two years on 99 chimpanzees at the Michale E. Keeling Center for Comparative Medicine and Research in Bastrop, Texas. They rated the apes on behavioral descriptors such as boldness, jealousy, friendliness and stinginess.

According to lead author Hani Freeman, postdoctoral fellow with the Lester E. Fisher Center for the Study and Conservation of Apes at Lincoln Park Zoo. “From an academic standpoint, the findings can inform investigations into the evolution of personality. From a practical standpoint, caretakers of chimpanzees living in zoos or elsewhere can now tailor individualized care based on each animal’s personality thereby improving animal welfare.”

Chimps Make a Movie

A group of 11 chimpanzees living in Edinburgh, Scotland have created a film using specially created cameras dubbed ChimpCams. The movie came about as part of research being done by primatologist Betsy Herrelko, who is studying for her PhD.

Herrelko introduced the video technology to the chimps over an 18 month period. She created two goals for the chimpanzees: to learn to select videos to watch using a touchscreen and to learn to record their own videos using the ChimpCam.

By observing what videos the chimpanzees watched, Herrelko was able to determine what chimpanzees prefer to see. The chimps were allowed to choose videos of their enclosure or video of the area where zoo staff prepares their food. While an in-depth analysis of their viewing habits has not been done, it appears that the chimps have no preference for either set of videos.

The chimps were much more interested in the ChimpCam and enjoyed watching the video screen as they filmed their lives in the enclosure.

The film, ChimpCam, will be shown on BBC 2 on Wednesday, January 27th.

For more, and for a clip of the film, visit the BBC.

Chimps Use Tools to Cut Food

Chimps have been observed using stone and wooden cleavers to chop up food in the Nimba Mountains of Guinea, Africa. The chimps were seen breaking into Treculia fruits, which are hard shelled and volleyball-sized, and then cutting them into smaller portions.

Chimps have been observed using tools in the past to find food, including stones to crush nuts and twigs to fish termites out of holes. This is the first time that chimps have been seen using tools to process food after obtaining it.

Read more at the BBC.

Study Shows Chimpanzees Have Excellent Spatial Memory

Chimpanzee

Primatologists Emmanuelle Normand, Christophe Boesch, and Simone Ban recently conducted a study focused on the spatial memory of chimpanzees. Using GPS, the team mapped the location of 12,500 individual trees within the home range of a group of chimps in the Tai National Park in Ivory Coast.  Then, after tracking which trees the chimps regularly fed from, the researchers found that chimps would specifically seek out certain fruit trees depending on when the fruit was in season.

According to Normand:

“Across all seasons, it seems that they have preferred tree species. Like when it is the coula nuts season, chimpanzees crack nuts using tools for hours during a day. Or when it is the Sacoglottis fruits season, then the chimpanzees stay hours digging their fruit wadge in the water to press a maximum of juice from those fruits.”

The team believes this preference for fruit and the need to remember where the fruit trees are and when they are in season drove the evolutionary development of the primate brain.  Another primate who also has a penchant for finding their favorite fruit within a vast forest range is the Bornean orangutan.

For more information about the chimp study, see: BBC Earth News.