Program No.18-016

Study on Social behaviors of Wild Borneo Orangutans ; focusing on males


5th September,2006 - 16th December,2006

During the research from September to December 2006, I could track and observe 9 resident orangutans. Total observation time was 158 hours 21 minute. Results of fallen fruits census in 2006 showed that there were no remarkable fruit season that was observed from July to September in 2004 and 2005. According to the results of the nest census, the estimated density of the orangutan during this research period (1.6/km2, September-December 2006)was lower than the average density in the total research period (2.9/km2,2004-2006). I also observed an orangutan, which was a subject of our long term monitoring, died of wound bitten by a leopard. I followed this orangutan for 7 days until it died from infection. I will report this important observation as a case report.

Injured orangutan(Juvenile Female:5years old)

The Orangutan was eating ginger on the previous day when she dies.

HOPE Project<>