Abstract # 4293 Poster # 147:

Scheduled for Friday, June 22, 2012 07:00 PM-09:00 PM: Session 22 (Gardenia) Poster Presentation


FEEDING BEHAVIOR BY RING-TAILED LEMURS AT BERENTY RESERVE MADAGASCAR: A COMPARISON OF FOCAL ANIMAL AND GROUP SCAN SAMPLING METHODS.

S. Peterson, A. Niemeyer, A. T. Kuykendall and A. S. Mertl-Millhollen
Department of Anthropology; Portland State University, Portland, Oregon 97202, USA
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     Published reports indicate that ring-tailed lemurs (Lemur catta) at Berenty Reserve, Madagascar, spend as high as 47% of their time feeding. We predicted that the use of particular group scan sampling rules resulted in feeding rates that are higher than actual rates. We tested this by having multiple observers simultaneously record 5-minute time point samples of lemur activity using two different behavioral sampling methods. For the focal samples, the behavior of a focal individual was recorded for a full day, and different individuals were chosen daily. For the scan samples the behavior of the majority of the troop was recorded; however, if any individual was feeding or foraging, that activity took precedence and feeding was recorded. We collected seventeen days of data in June/July 2010 on the four females and one male in gallery forest troop CX. We recorded feeding for 40.92% of the 2016 group scan samples, and significantly fewer, 22.48%, in the 1308 focal samples when the focal animal was in view(The sign test, N=17, P<.001).These data will allow us to look at individual patch use by combining the two methods, however, we have demonstrated that scan sampling with feeding taking precedence, results in feeding rates that are higher than actual rates. Consequentially, we suggest that researchers should be very explicit about the details of decision rules when describing observation methods.