Abstract

Estimating Orangutan Populations - How Important is Systematic Habitat Mapping?
Track: Parks and Natural Reserves
Author(s): Leslie Bolick, Birute Galdikas, Nancy Briggs

Tropical deforestation in Borneo and Sumatra threatens the persistence of the endangered orangutan. Assessing the exact area and distribution of remaining orangutan populations is urgently needed for their conservation. Researchers use standard techniques to assess orangutan population densities based on line transect nest counts. Then these data are combined with habitat mapping to assess population distribution and abundance. Habitat mapping that relies on unsystematic methods or outdated imagery can lead to large errors in population assessments. Orangutan Foundation International researchers have developed methods to map orangutan habitat for Tanjung Puting National Park using systematic remote sensing and G.I.S. techniques, which produce more robust population assessments. Comparisons with older, less accurate habitat maps show significant variability and inaccuracy in orangutan population abundance and distribution. This exercise underscores the importance of developing systematic habitat mapping methods using remote sensing and GIS, especially when using these data to estimate species distribution and abundance.

Leslie Bolick
Orangutan Foundation International
1004 Cypress Ln
Davis , California 95616
United States
Phone: 530-757-7842
E-mail: leslie.ofi@gmail.com

Birute Galdikas
Orangutan Foundation International
4201 Wilshire Blvd
Losa Angeles , California 90010
United States
Phone: (323) 938-6046
E-mail: DrBirute@gmail.com

Nancy Briggs
CSULB
1250 Bellflower Blvd
Long Beach , California 90840
United States
Phone: 562 985 4300
E-mail: nbriggs@csulb.edu