Presentation on theme: "Crouching Tigers Hidden Prey: Sumatran tiger and prey populations in a tropical forest landscape Paper by: Timothy G. O’Brien, Margaret F. Kinnaird, and."— Presentation transcript:
Crouching Tigers Hidden Prey: Sumatran tiger and prey populations in a tropical forest landscape Paper by: Timothy G. O’Brien, Margaret F. Kinnaird, and Hariyo T. Wibisono Animal Conservation 2003 131-139 Presented by: Caroline Mullis Geography Major Geog 370
Spatial Problem Problem: Looking at the distribution and abundance of Sumatran tigers and nine prey species in Selatan National Park, in Sumatra, Indonesia Hypothesis: Habitat loss and illegal hunting of prey and the tigers are responsible for the observed patterns of abundance (decrease).
Methods, Data, and Test Method: Use of passive infared camera-traps to assess abundance and distribution of tigers relative to prey availability, park boundaries and density of human population. Cameras set in 10 by 2 km sampling blocks, oriented from park boundary toward park interior to detect edge effects. Photo taken when sensor triggered, dated and timed. Traps left for 35 days. Cameras were retrieved from locations filmed examined for tigers and prey RAI- relative-abundance indices were calculated from the number of independent photographs of a species with number of days it took to acquire. (measured effort expected to increase as density decreased) Same area was sampled before, and goal was to compare camera trap abundance indices with density estimates from using the CAPTURE method previously developed by Nichols (1998). Used linear regression on RAI
Results Using CAPTURE model to determine density within sampling area Results found that tiger abundance varied with abundance of large prey (pigs), strong correlation. RAI-2 four times higher for tigers in areas of low human density. Goal of study first to demonstrate that abundance of tigers and prey are directly related to independently derived estimates of densities, and show influence of human densities on abundance.
Conclusions Need for monitoring habitat conditions, prey populations, and monitoring poaching will help prevent the furthering of the endangerment of the tigers. Criticisms: effective use of camera traps and good explanation of RAI’s but lack of original conclusion. Useful to include further suggestions of remedies.