An anthropologist in England investigated personality in chimpanzees (Pan troglodytes), looking at which behavioral traits were exhibited consistently in individuals, which traits correlated with one another, and how personality differed between males and females.
With the help of several students, she observed the behavior of 75 chimpanzees from 3 different zoos over the course of three years. They recorded information about each chimp’s behavior, who they stayed in close proximity to, and who they groomed. They found that many behaviors were exhibited consistently over time by the individuals who performed them. They also found that certain behavioral traits were significantly correlated with one another, suggesting the presence of personality groups. For instance, frequency of approaching others in a friendly manner and frequency of play and affinitive behaviors (e.g. hugs and kisses) were strongly correlated. The five personality groups she identified were “sociability”, “positive affect”, “equitability”, “anxiety”, and “activity”. Finally, she found that males were more positive, equitable, anxious, and active than females though the two sexes didn’t differ in their level of sociability. Continue reading
In the current issue of the journal Animal Behavior, researchers from Indiana describe their work investigating the stability of social niches (patterns of sociability and attractiveness to others) in Brown-headed cowbirds (Molothrus ater) across experimental disturbances in group composition.
The experimenters split groups of birds being housed together into two smaller groups and then put the group back together after three days. This procedure was run once with a group of adult birds and once with a group of juvenile birds. Throughout the length of the experiment, researchers regularly observed the groups and documented all instances in which an individual closely approached another in a non-threatening manner. Continue reading
Researchers from Italy and the United States investigated the effect of a parasite (Polistes dominulus) on the behavior and morphology of eusocial paper wasps (Xenos vesparum).
By collecting aggregated wasps before, during, and after typical hibernation periods and investigating their parasite load, they found that infected wasps formed hibernation aggregations before uninfected wasps and stayed in these aggregations further into the post-hibernation period. After dissecting both uninfected and infected female wasps, they also found that infected wasps were smaller and more asymmetrical, had undeveloped ovaries, and had lower fat stores than uninfected wasps. Essentially, these parasites steal nutrients from their hosts and induce them to become extra gregarious in order to promote their own reproduction. Now that’s a social circle I don’t want to be part of!
Citation: In Press: Beani, L., Dallai, R., Mercati, D., Cappa F., Giusti, F, and Manfredini, F. When a parasite breaks all the rules of a colony: morphology and fate of wasps infected by a strepsipteran endoparasite, Animal Behavior (2011).
Camping on the shore of Black Bass Lake
I woke up today to the sounds of nature, with the shore of a lake just outside my door. Had I suddenly been transported to Gombe? No, not yet, but I did spend much of this weekend enjoying the great outdoors. My boyfriend and I decided to go camping at Mille Lacs Kathio State Park in Central Minnesota. We opted for a hike-in campsite, as they often offer a more rustic camping experience. As I went for a hike this morning along the rolling hills surrounding Black Bass Lake, I began thinking about how my years of camping had helped prepare me for my fieldwork. Continue reading
Bikers in Mankato River Ramble
Gombe National Park consists of a series of rifts and valleys positioned perpendicularly to Lake Tanganika. Thus, not only must you climb in order to get from the beach to the forest, but also in nearly any direction you travel once there. Needless to say, it is the most physically challenging work environment I have ever had. It has been over two years since my last stay at Gombe, and while I try to maintain a reasonable level of fitness, I think it’s time to kick it into high gear.
Since I returned to Minnesota a few weeks ago, I’ve begun bike commuting to and from the University again. This gets me a minimum of 9 miles a day. It’s a good start, but not comparable to climbing up ravines, crawling under vine tangles, and sliding down slopes. Thus, I jumped at the chance to participate today in the Mankato River Ramble, a 42 mile organized ride held in southern Minnesota. It’s been awhile since I’ve been on an extended ride so this was the perfect opportunity to take my physical activity to the next level. It was a beautiful day with unusually warm weather for this time of year. While stretches of riding interspersed with rest stops containing arrays of pies and other baked goods is not exactly Gombe-esque it was an enjoyable step in the right direction. With about three and a half months till my departure, I must continue my efforts to get Gombe-ready. I might need to get creative….