NEW GENETICS RESEARCH ON LEOPARDS AND TIGERS IN INDIA UNDERSCORES IMPORTANCE OF PROTECTING FOREST CORRIDORS

STUDY PROVIDES FIRST DEFINITIVE GENETIC DATA CONFIRMING UTILITY OF VITAL CORRIDORS
As rapid economic expansion continues to shape the Asian landscape on which many species depend, time is running out for conservationists aiming to save wildlife such as tigers and leopards. Scientists at the Smithsonian Conservation Biology Institute have used genetic analysis to find that the natural forest corridors in India are essential to ensuring a future for these species. According to two studies recently published in two papers, these corridors are successfully connecting populations of tigers and leopards to ensure genetic diversity and gene flow. The results of the study that focused on tigers were published in Ecology and Evolution, and the results from the study that tracked leopards were published in Diversity and Distributions.

"This research provides crucial information about the need to maintain these vital veins to support tiger and leopard populations," said Sandeep Sharma, SCBI visiting scholar and lead author of the Ecology and Evolution paper. "These habitats and corridors in India are threatened by infrastructural developments and need to be conserved if we want to save these species for future generations."

Habitat fragmentation can divide populations of species into isolated groups, which can lead to inbreeding and a genetic bottleneck that affects the long-term viability of the population. Scientists can determine the scope of such isolation by analyzing the extent to which groups of the same species from one range have become genetically distinct. The authors of the two papers used fecal samples to analyze the genetics of tiger and leopard populations in four reserves in central India: Satpura, Melghat, Pench and Kanha. The Kanha and Pench reserves and the Satpura and Melghat reserves are connected via forest corridors that tigers, leopards, humans and cattle share.

The researchers found that both tiger and leopard populations in the reserves had maintained a high level of genetic diversity. Neither tigers nor leopards were genetically distinct, with one exception among the leopards, which the scientists hope to explain with additional research. The corridors appear to allow individuals to move between reserves, facilitating genetic exchange.

However, the proliferation of roads, rail lines, mining, urbanization and other forms of development through the corridors jeopardize these species' ability to move between reserves. Several coal mines have been proposed in the forest corridor between the Satpura and Pench tiger reserves, as has the widening of a national highway (NH-7) and a broad-gauge railway line that cut across the corridor between the Kanha and Pench tiger reserves.

"By looking at two species, we were really able to illustrate the functionality of these corridors," said Trishna Dutta, SCBI visiting student and lead author of the Diversity and Distributions paper. "Conserving a whole landscape, rather than piecemeal protected areas, would ensure a better chance for the long-term persistence of these and other species."

The Indian subcontinent contains the largest number of tiger conservation areas, which are home to 60 percent of the world's wild tigers. Leopard range has historically extended through most of sub-Saharan Africa, along parts of the North African coast, through central, south and southeast Asia and north to the Amur River valley in Russia.

In addition to Sharma and Dutta, the papers' other SCBI authors are Jesús Maldonado, a research geneticist at SCBI's Center for Conservation and Evolutionary Genetics, and John Seidensticker, head of SCBI's Conservation Ecology Center. The other authors are Thomas Wood in the Department of Environmental Science and Policy at George Mason University and H.S. Panwar, former director of Project Tiger India and Wildlife Institute of India.

The Smithsonian Conservation Biology Institute plays a key role in the Smithsonian's global efforts to understand and conserve species and train future generations of conservationists. Headquartered in Front Royal, Va., SCBI facilitates and promotes research programs based at Front Royal, the National Zoo in Washington, D.C., and at field research stations and training sites worldwide.

At Least One in Six Stars Has an Earth-sized Planet

The quest for a twin Earth is heating up. Using NASA’s Kepler spacecraft, astronomers are beginning to find Earth-sized planets orbiting distant stars. A new analysis of Kepler data shows that about 17 percent of stars have an Earth-sized planet in an orbit closer than Mercury. Since the Milky Way has about 100 billion stars, there are at least 17 billion Earth-sized worlds out there.

Francois Fressin, of the Harvard-Smithsonian Center for Astrophysics, presented the analysis today in a press conference at a meeting of the American Astronomical Society in Long Beach, Calif. A paper detailing the research has been accepted for publication in The Astrophysical Journal.

Kepler detects planetary candidates using the transit method, watching for a planet to cross its star and create a mini-eclipse that dims the star slightly. The first 16 months of the survey identified about 2,400 candidates. Astronomers then asked, how many of those signals are real, and how many planets did Kepler miss?

By simulating the Kepler survey, Fressin and his colleagues were able to correct both the impurity and the incompleteness of this list of candidates to recover the true occurrence of planets orbiting other stars, down to the size of Earth.

“There is a list of astrophysical configurations that can mimic planet signals, but altogether, they can only account for one-tenth of the huge number of Kepler candidates. All the other signals are bona-fide planets,” said Fressin.

Most sun-like stars have planets

Altogether, the researchers found that 50 percent of stars have a planet of Earth-size or larger in a close orbit. By adding larger planets, which have been detected in wider orbits up to the orbital distance of the Earth, this number reaches 70 percent.

Extrapolating from Kepler’s currently ongoing observations and results from other detection techniques, it looks like practically all Sun-like stars have planets.

The team then grouped planets into five different sizes. They found that 17 percent of stars have a planet 0.8 – 1.25 times the size of Earth in an orbit of 85 days or less. About one-fourth of stars have a super-Earth (1.25 – 2 times the size of Earth) in an orbit of 150 days or less. (Larger planets can be detected at greater distances more easily.) The same fraction of stars has a mini-Neptune (2 – 4 times Earth) in orbits up to 250 days long.

Larger planets are much less common. Only about 3 percent of stars have a large Neptune (4 – 6 times Earth), and only 5 percent of stars have a gas giant (6 – 22 times Earth) in an orbit of 400 days or less.

Smaller planets are not picky

The researchers also asked whether certain sizes of planets are more or less common around certain types of stars. They found that for every planet size except gas giants, the type of star does not matter. Neptunes are found just as frequently around red dwarfs as they are around sun-like stars. The same is true for smaller worlds. This contradicts previous findings.

“Earths and super-Earths aren’t picky. We’re finding them in all kinds of neighborhoods,” said co-author Guillermo Torres of the CfA.

Planets closer to their stars are easier to find because they transit more frequently. As more data are gathered, planets in larger orbits will come to light. In particular, Kepler’s extended mission should allow it to spot Earth-sized planets at greater distances, including Earth-like orbits in the habitable zone.

SMITHSONIAN CONSERVATION BIOLOGY INSTITUTE PUBLISHES TWO SIGNIFICANT PANDA STUDIES

Photo by Mehgan Murphy, Smithsonian's National Zoo

Two new research papers by Smithsonian Conservation Biology Institute scientists and partners will help conservation biologists make strides in saving the fewer than 1,600 giant pandas left in the mountain forests of central China. Over the years SCBI has worked to conserve giant pandas by studying every aspect of their lives—their natural history, reproductive physiology and optimal habitat.

Male Reproduction Surprises Scientists

The first paper, set to be published in the Biology of Reproduction's Papers-in-Press April 4, finds that male pandas, like female pandas, experience reproductive seasonality, but the time frame of reproductive viability differs greatly between the two sexes. Researchers have thoroughly studied female panda reproduction and found that a female panda's estrus cycle occurs only once a year for only 24 to 72 hours. Until now, no one has extensively studied the male giant panda's reproductive capacity over time. This study finds that males are reproductively viable for six or more months out of the year, which is significantly longer than females, indicating that the two sexes have evolved very different reproductive strategies.

Mei Xiang (may-SHONG) and Tian Tian (tee-YEN tee-YEN)
 have resided at the Smithsonian’s National
Zoological Park since Dec. 6, 2000. They
are the second pair of pandas to live at the Zoo.

"The giant panda is perhaps the most high-profile endangered species on Earth, and it is also one of the most well studied," said Dr. Copper Aitken-Palmer, lead author of the paper and SCBI's head veterinarian. "As such, it is amazing that we did not previously understand the basic physiological changes occurring in the male giant panda during the breeding season and outside of it. With this information, we now have a complete picture of what is occurring physiologically for both males and females during reproduction."

For three years, the paper's authors evaluated the interrelated seasonal changes in male panda testosterone levels, sperm concentration, testes size and reproductive behavior in eight male giant pandas with their colleagues at the Chengdu Base of Giant Panda Breeding in China. They found that unlike females, reproductive fitness in the male giant panda changes over time with sperm production already beginning three to five months before females enter estrus. According to Aitken-Palmer, these results show that male pandas have developed the ability to produce sperm over a long period of time to ensure they have sperm when the brief and unpredictable female panda estrus occurs.

Climate Change Claiming Panda Habitat

The second study, published in the International Journal of Ecology in March, used two different global climate models to find that more than 16,000 kilometers2 of giant panda habitat will likely be lost by 2080 as climate change causes giant panda habitat systems to shift to higher elevations and latitudes. That means that less than half of their already significantly decreased habitat is projected to be suitable in about 70 years. The two models take into account remaining habitat, lost habitat, potential new habitat and current protected areas for giant pandas. The study also finds that habitat fragmentation will likely increase, leading to smaller areas that can support fewer pandas farther away from each other, increasing the risks of inbreeding and population collapse.

1972: Ling-Ling and Hsing-Hsing (Shing-Shing), the
National Zoo’s first pair of giant pandas, arrived from
China in 1972 as a gift to the American people to
commemorate President Nixon’s historic visit to China

"Our research predicts that climate change will substantially decrease the amount of suitable giant panda habitat within the species' current distribution, but also that we may see new areas becoming suitable for giant pandas," said Melissa Songer, lead author of the paper and an SCBI wildlife ecology. "The question remains as to whether giant pandas will have the capacity and opportunity to shift to new areas should they become viable. Our work is an important step in developing climate adaptation strategies and in identifying critical areas that will most likely be suitable and accessible for giant pandas in the face of climate change."

In addition to calling for the development of more protected areas that are aligned with climate predictions, the paper emphasizes the importance of creating corridors to reduce fragmentation. The study also has land-use implications, as agricultural land and land near human settlements are unsuitable for pandas.

Visitors can visit two giant pandas, Mei Xiang and Tian Tian, at the Smithsonian's National Zoo. Although the two pandas have bred early in the year for the last few years, so far Mei Xiang has not gone into estrus this year. SCBI scientists, veterinarians and animal care staff continue to monitor both pandas' behavior and Mei Xiang's hormones in preparation for breeding season.

Mei Xiang (may-SHONG), the National Zoo’s female giant
panda, gave birth to a cub Sunday, Sept. 16, at 10:46 p.m.
National Zoo staff can hear the cub but have not yet seen it as
Mei Xianghas built a substantial nest in her den. This is the
 secondcub born to Mei Xiang and male panda Tian Tian
 (tee-YEN tee-YEN) as the result of artificial insemination.

In addition to Aitken-Palmer, the authors of the panda reproduction study from SCBI are Caitlin Burrell, Dave Wildt and the late Dr. JoGayle Howard. Partnering authors are Dr. Rong Hou, Zhihe Zhang and Chengdong Wang at the Chengdu Research Base of Giant Panda Breeding; Rebecca Spindler at Toronto Zoo; and Mary Ann Ottinger at the Department of Animal and Avian Sciences at the University of Maryland.

In addition to Songer, the authors of the panda ecology study from SCBI are Melanie Delion and Alex Biggs. The partnering author is Qiongyu Huang in the geography department at the University of Maryland. Friends of the National Zoo helped fund this research.

The Smithsonian Conservation Biology Institute plays a key role in the Smithsonian's global efforts to understand and conserve species and train future generations of conservationists. Headquartered at a Smithsonian facility in Front Royal, Va., SCBI facilitates and promotes research programs based at Front Royal, the
 National Zoo in Washington, D.C., and at field research stations and training sites worldwide.