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The Endangered Orangutan and Tiger: PLoS Biology Press Release

November 30, 2004

Tracking orangutans from the sky

From the hundreds of thousands of orangutans that once ranged throughout southeast Asia, only two orangutan species now inhabit just two countries: Indonesia and Malaysia. The Sumatran orangutan is listed as critically endangered, the Bornean, endangered. In a new study published in the open access journal PLoS Biology, Marc Ancrenaz and colleagues report an innovative method for reliably counting orangutan numbers from the sky, and estimate that the entire population in Sabah has dropped by 35% in the past 20 years.

Conservation efforts depend on having reliable data on population size, density, and distribution, but estimates of orangutan numbers in Sabah-which range from 2,000 to 20,000-are outdated. Orangutans are tough to spot directly, so researchers traditionally count the nests they sleep in at night, which is time-consuming, especially when faced with the hip-deep muck and steep slopes of the rainforest floor. Instead, Ancrenaz and colleagues have developed a survey method by which estimates of orangutan numbers can be made from helicopters. By comparing ground survey data, collected over two years, with aerial counts garnered in only 72 hours the authors calibrated and refined their aerial survey results and were able to directly assess the distribution and size of orangutan populations throughout the whole of Sabah (an area of 72,000 square kilometers).

The authors attribute the 35% decline in Sabah orangutan numbers primarily to habitat loss from agricultural development. While the authors acknowledge the density estimates could be more precise, their survey reveals crucial information on orangutan numbers and distribution, and their results suggest that orangutans may adapt better to degraded forests than previously thought-provided illegal hunting and agricultural conversion are controlled. Having reliable estimates of orangutan numbers is vital to conservation efforts. These aerial surveys will speed that work, and help sustain orangutans' refuge in the treetops, above their human relatives.

Citation: Ancrenaz M, Gimenez O, Ambu L, Ankrenaz K, Andau P, et al. (2004) Aerial surveys give new estimates for orangutans in Sabah, Malaysia. PLoS Biol 3 (1): e3.

The published article will be accessible to your readers at:
http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0030003

Press-only preview of the article: http://www.plos.org/downloads/plbi-03-01-ancrenaz.pdf


CONTACT:
Marc Ancrenaz
KOCP
PO Box 3109
Sandakan, Sabah Malaysia 90734
+60-88-250-540
+60-88-250-540 (fax)
hutan1@tm.net.my

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A new tiger subspecies?

"Tyger! Tyger! burning bright / In the forests of the night / What immortal hand or eye / Could frame thy fearful symmetry?" When William Blake wrote these words in the late 1700s, the deforestation and habitat destruction that would decimate wild tiger populations had already begun. In 1900, an estimated 100,000 wild tigers lived throughout much of Asia, from India in the west to Sumatra and Indonesia in the south to Siberia in the east. Today, the ongoing stresses of habitat loss, hunting, and an illegal trade in tiger parts have spared fewer than 7,000 tigers. Of eight traditionally classified subspecies of Panthera tigris, three have gone extinct since the 1940s. In PLoS Biology, evidence is now reported for a new tiger subspecies.

Conservation strategies to combat the grinding attrition of tiger populations are tailored to each subspecies. But several lines of evidence suggest that subspecies designations-based on geographic range and morphological traits such as body size, skull traits, coat color, and striping patterns-may be flawed. To get a clearer picture of the genetic structure of existing tiger populations, Shu-Jin Luo, Jae-Heup Kim, Stephen O'Brien, and colleagues have performed a comprehensive genetic analysis of over 130 tigers.

DNA was extracted from tigers originating in the Russian far east (Siberian, or Amur, tigers), south China, northern Indochina, the Malaya Peninsula, Sumatra, and the Indian subcontinent. Some of the analysis supported traditional classifications-e.g., for the Sumatran and Bengal tigers-but others suggested that the Indochinese subspecies should be divided into two groups, representing a northern Indochinese and a peninsular Malaya population (which the authors designated respectively as P. t. corbetti and P. t. jacksoni, after the tiger conservationist Peter Jackson).

The distinct genetic patterns found in the tiger populations suggest six rather than five living subspecies, with distinct patterns of genetic variability. Whether recent population and habitat declines, as opposed to earlier events, can fully explain these patterns is not clear. But these results offer valuable data for conservation strategies and captive breeding programs.

Citation: Luo S, Kim J, Johnson W, van der Walt J, Martenson J, et al. (2004) Phylogeography and genetic ancestry of tigers Panthera tigris. PLoS Biol 2 (12): e442.

The published article will be accessible to your readers at:
http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0020442

Press-only preview of the article: http://www.plos.org/downloads/plbi-02-12-luo.pdf

Related image for press use: http://www.plos.org/downloads/plbi-02-12-luo.jpg
Caption for image: A Bengal tiger in the tall grassland in India. Photograph by Ullas Karanth.

CONTACT:
Shu-Jin Luo
National Cancer Institute
Laboratory of Genomic Diversity
Bldg 560, Rm 11-84
Frederick, MD USA 21702
+1-301-846-7491
+1-301-846-6327 (fax)
luos@ncifcrf.gov


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THE FOLLOWING RESEARCH ARTICLE WILL ALSO BE PUBLISHED ONLINE:

Algorithmic self-assembly of DNA Sierpinski Triangles

Engineered DNA self-assembly to produce a fractal pattern demonstrates all the necessary mechanisms for the molecular implementation of arbitrary cellular automata.

Citation: Rothemund P, Papadakis N, Winfree E. (2004) Algorithmic self-assembly of DNA Sierpinski Triangles. PLoS Biol 2 (12): e424.

The published article will be accessible to your readers at:
http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0020424

Press-only preview of the article: http://www.plos.org/downloads/plbi-02-12-winfree.pdf


CONTACT:
Erik Winfree
California Institute of Technology
Computer Science and Computation & Neural Systems
1200 E. California Blvd.
Pasadena, CA USA 91125
+1-626-395-6246
+1-626-584-0630 (fax)
winfree@caltech.edu


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