Tuesday, July 9, 2013

Target, Interrupted

By Moira Donovan, IRES 2013

Hey there! I’m Moira, one of the new IRES students assisting the lab this summer. I’m currently stationed in the Serena Camp, helping with “Target” trials. “Target” is a life-size styrofoam model of a hyena, made by a company that manufactures archery targets—hence his name. Julie, the graduate student whose research I am helping with, uses Target to test hyena “boldness.” Her research focuses on social intelligence (how well a hyena interacts with others in a group environment) and personality aspects that might contribute to it. We measure boldness by observing whether a hyena approaches Target and when the hyena realizes Target is not an actual hyena.

In order to conduct a Target trial, we first need to find a lone hyena traveling a predictable path. We then drive ahead of the hyena, deposit Target along its path, and wait nearby to observe what the hyena does. Two nights ago, Julie, Lily, and I went out on our usual evening observations in search of an opportunity for a Target trial. We drove to the Happy Zebra Clan Territory, hoping to find an unsuspecting individual. I never imagined I would be so lucky as to experience what happened next.

Target and Moira

Soon after entering the territory, we spotted a single hyena loping along. We sat in our seats, deciding whether this would be a proper candidate for a trial, as the hyena rushed across the road and continued in a straight line. Clearly, this one was headed somewhere important. As Lily turned the Hilux off-road and we began to pursue, the urgency of the chase dawned on us – we could hardly keep up at 25kph. We hit a rocky portion, forcing us to slow down, and we were sure we would lose sight of the unidentified hyena. As we maneuvered around the rocks we saw three more hyenas join the first, bolting toward a herd of Cape buffalo. On the outskirts of what must have been 200 buffalo, we saw the hyenas and knew we were going to witness something extraordinary.

Spotted hyenas typically prefer to hunt alone rather than potentially lose their meal to a higher-ranked individual. This time, however, we spotted at least ten individuals when we got there, and a few others arrived in the following hour. Despite our difficulties recording hyena behavior through the darkness, rain, and tall grass, the effects of a large hunting party were clear. While two hyenas warded off an adult buffalo’s charges, several others closed a circle around a fallen calf and began to feed, taking advantage of their allies’ efforts. Once the adult buffalo gave up on trying to protect the calf, what followed may have seemed to the untrained eye (like mine) like a free-for-all between the hungry hyenas. But if you can observe closely, and if you know the identity and social status of each hyena, you can see method in the madness.

Higher-ranked individuals have priority of access to resources. In spotted hyena society, this means that feeding order is dictated by matriline: the highest-ranked female and her relatives eat first, then the next highest-ranked female and her relatives, and so on. The more dominant clan-mates chase off lower-ranked individuals who attempt to feed before their turns. Since immigrant males are at the bottom of the hierarchy, the three that were present were pushed to the outskirts and could only feed on scraps. As this event unfolded on just my the third night in the Mara, I had no clue as to which hyenas were who, but followed Julie and Lily as they called out behaviors and IDs while I filmed.

After the excitement of the hunt comes the analysis of the video. Because of the darkness and chaos of the hunt, we were unable to accurately identify individuals or behaviors at the time. Video recordings of events can be watched over and over again and at slow speed, to allow us to see what the hyenas actually did that night. One hour of video footage equated to three solid days of analysis. For analysis, all of the important behaviors performed by the hyenas are recorded in a text shorthand transcription for later reference. In order to record behaviors, however, one must be competent in identifying individual hyenas. I have not yet reached competence in that regard, but look forward to the day when my skills allow me to argue with another research assistant about who will drive during and who will transcribe after our observations.

In the past week, I have learned that most days in the field do not include so much drama. Although we didn’t manage to do a Target trial that evening, such interruptions in data collection add to the unpredictability of the field. In a place as new to me as the Mara, though, it’s the small and seemingly unremarkable moments that renew this experience, day after day. So, until I see another kill, the everyday beauty of the Mara – from the sunset reflecting off the grass to seeing the cutest baby elephant or a species of bird I never knew existed – keeps me fixed on this place. In the meantime, I am hoping for some Target trials….

1 comment:

dee said...

Great blog! Please keep it up.

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