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Endangered Giant Pandas Genetically Diverse Enough for Recovery FREDERICK, Maryland, January 3, 2002 (ENS) - There are only about 1,000 giant pandas left in the wild, but there is still hope for this endangered species. A comprehensive genetic analysis of three wild giant panda populations shows that they still have enough genetic diversity to recover. The research was a collaboration between the Laboratory of Genomic Diversity at the National Cancer Institute in Frederick, Maryland, Peking University, the Chinese Zoo Association and Wolong Nature Reserve. "From a strictly genetic perspective, the giant panda species and the three populations look promising...they have retained a large amount of diversity in each population," say Dr. Lu Zhi of Peking University in Beijing, China, Stephen O'Brien of the Laboratory of Genomic Diversity, and their co-authors in the December issue of "Conservation Biology."
Despite being one of the most recognized symbols of the conservation movement, the world's last 1,000 giant pandas are struggling to survive, the World Wide Fund for Nature said in a report last February to mark the 40th anniversary of this group that has adopted the panda as its logo. Lu Zhi, co-author of the new genetic study, also co-authored the WWF's "Giant Pandas in the Wild." The former coordinator of WWF's panda program in China, Dr. Lu says the disappearance and fragmentation of pandas' rugged mountain forest home are the "major extinction threats" this endangered species is facing. "Habitat fragmentation is especially dangerous for pandas, as they must adjust to the life cycles of bamboos, which flower and die periodically," said Dr. Lu. Bamboo, the panda's main food, flowers once every century and then dies out. When entire bamboo forests die out, pandas can starve to death if they are unable to move to another area. Dr. Lu said, "Small, isolated populations of giant pandas, whose diet consists almost entirely of various bamboo species found in high mountain areas, face a risk of inbreeding. This could lead to reduced resistance to disease, less adaptability to environmental change, and a decrease in reproductive rates." Assisted by conservation organizations, the Chinese government has recently stepped up efforts to protect the pandas. Since 1993 the number of reserves has increased from 14 to 33, and the pandas are monitored and patrolled more frequently. Biologists estimate that the remaining giant pandas are divided into about 25 populations with fewer than 20 individuals each. Because small, isolated populations are more likely to die out, this increases the risk that the species will become extinct. Dr. Lu, O'Brien and their colleagues analyzed the genetic variation in giant pandas primarily from populations in three mountain ranges - one, Qinling, that is separated from the others by a 75 mile wide valley, and two that are adjacent, Minshan and Qionglai. The researchers found that the giant panda has moderate genetic diversity compared with other carnivores. "The giant panda is comparable to the genetically healthy Serengeti lion population in its endemic diversity and far greater than the genetically compromised Asiatic lion from India's Gir forest or the Florida panther," says O'Brien. While the giant panda's overall genetic diversity is encouraging, the researchers also found evidence that the Qinling panda population, which is across the valley from the other two, is genetically isolated. The results suggest that this isolation occurred within the last few thousand years, which coincides with the valley's settlement by Chinese people. Despite the Qinling population's genetic isolation, there does not yet appear to be significant inbreeding.
Dr. Jianguo Liu, an associate professor of fisheries and wildlife at Michigan State University has conducted a 32 year analysis of satellite images of the Wolong Nature Reserve in Sichuan Province, southwestern China where about 10 percent of the wild pandas live. Panda preservation has been a highly popular and publicized effort. The reserve has received considerable financial support from the Chinese government and international organizations, such as the WWF. But the rates of destruction were higher after the reserve was established in 1975 than before the reserve's creation, says Liu. The panda reserve has been a victim of its own existence. Towns and settlements have thrived in the Wolong Reserve. The local resident population has increased 70 percent since the reserve was established. So, by themselves, panda reserves are not sufficient for population recovery. Part of the key to saving giant pandas in the wild is restoring gene flow among populations by maintaining and reestablishing natural corridors between populations, according to Dr. Lu, O'Brien and their colleagues. They suggest that this effort could be incorporated into the national forest conservation program - which includes a logging ban and ecological restoration - that the Chinese government launched in 1998. Copyright Environment News Service (ENS) 2001. All rights reserved. |
Historically, giant pandas lived in forests from China to northern Burma
and Vietnam, but extensive deforestation has restricted the species to
six alpine forest fragments in the mountain ranges along the Tibetan
plateau in western China.
China's Wolong Nature Reserve, where some of the genetic research was done,
was established to be a panda recovery area. But growing human populations
near the reserve and crowds of tourists are squeezing the pandas into an
increasingly smaller area, an April 2001 study of satellite data shows.
