Sensing Distant Storms, Birds Flew the Coop

This male golden-winged warbler is carrying a geolocator on its back and identification bands on its legs. PHOTO: Gunnar Kramer

When birds unexpectedly flee their nesting grounds, it may be an indication from Mother Nature’s early-warning system that a massive storm is approaching.

While tracking the migratory patterns of a group of golden-winged warblers, a research team led by ecologist Henry Streby discovered that birds in the eastern Tennessee mountains fled their breeding grounds one to two days ahead of the arrival of powerful supercell storms. One such storm swept through the central and southern United States in April 2014, generating 84 tornadoes and killing 35 people.

“It is the first time we’ve documented this type of storm-avoidance behavior in birds during breeding season,” said Streby, who conducted the work while he was a National Science Foundation postdoctoral fellow and a visiting research scholar in the Department of Environmental Science, Policy, and Management (ESPM). Other members of the team are from the University of Minnesota, the University of Tennessee, and the U.S. Geological Survey.

“We know that birds can alter their route to avoid things during regular migration, but it hadn’t been shown until our study that they would leave once the migration was over and they’d established their breeding territory to escape severe weather,” Streby said. The warblers flew a total of 932 miles to avoid a severe weather system, then came right back to their nests after the storm passed. Notably, the birds fled while the storm was still 250 to 560 miles away, and local signs of inclement weather—changes in atmospheric pressure, temperature, and wind speed—were largely absent.

“At the same time that meteorologists on the Weather Channel were telling us this storm was headed in our direction, the birds were already packing their bags and evacuating the area,” said Streby, who led a paper describing the “evacuation migration” that was published December 18, 2014, in Current Biology.

After an analysis of the flight-pattern anomaly, infrasound— sound below the normal limits of human hearing—emerged as the most logical explanation. Scientists have known for decades that tornadoes produce very strong infrasound, and that birds can hear and respond to infrasound frequencies. But this paper presents the first evidence that birds use infrasound to remotely detect storms.

Making Old Blood Young Again

Mitochondria. iStockPhoto

Scientists have identified a new molecular pathway critical to aging, and confirmed that the process can be manipulated to help make old blood like new again. The researchers found that blood stem cells’ ability to repair damage caused by inappropriate protein folding in the mitochondria, a cell’s energy stations, is critical to their survival and regenerative capacity.

The discovery, published in the March 20 issue of the journal Science, has implications for research on reversing the signs of aging, a process thought to be caused by increased cellular stress and damage.

“Ultimately, a cell dies when it can’t deal well with stress,” said study senior author Danica Chen, an assistant professor in the Department of Nutritional Sciences and Toxicology (NST). “We found that by slowing down the activity of mitochondria in the blood stem cells of mice, we were able to enhance their capacity to handle stress and rejuvenate old blood. This confirms the significance of this pathway in the aging process.” The study gives researchers a new target for controlling the aging process, Chen said. Co–lead authors of the study are postdoctoral researcher Mary Mohrin and graduate students Jiyung Shin, Yufei Liu, and Katharine Brown, all of NST.

Chill Out, Lose Weight

A college student in Boston enjoys the winter’s record snowfall. PHOTO: Coleen Reid

A shot of cold air may kick-start extra fat-burning. A study found that exposure to cold temperatures increases levels of a newly discovered protein that is critical for the formation of brown fat, the type of fat in our bodies that generates heat.

With extended exposure to chilly air, the protein, called transcription factor Zfp516, also helps the more abundant white fat in our bodies—the kind that stores excess energy—become more similar to brown fat in its ability to burn energy. Mice with boosted levels of the protein gained 30 percent less weight than control mice when both groups were fed a high-fat diet. The new findings were published online January 8 in the journal Molecular Cell.

“Knowing which proteins regulate brown fat is significant because not only is brown fat important for [generating heat], but there is evidence that it may also affect metabolism and insulin resistance,” said principal investigator Hei Sook Sul, professor of nutritional sciences and toxicology.

The researchers noted that there are many steps between discovering the protein in mice and determining whether it can be useful in humans, but they said that having a clear target is an important development.


[PHOTO: Maddie Girard]

ESPM graduate student Maddie Girard identified two new species of peacock spider, a genus known for its bright colors and elaborate courtship “dances.” Watch the impressive booty-shaking in this Science Friday video featuring Girard and the sparklemuffin, one of her recent discoveries.

New Mushroom Species Found on Campus

PMB research associate Else Vellinga shows off a new species of mushroom discovered on campus. PHOTO: Jewel Reaso

Researchers Else Vellinga and Nhu Nguyen, PhD ’13 Plant and Microbial Biology (PMB), have named the first new species of mushroom from the UC Berkeley campus in more than 30 years. They found and described Helvella dryophila, a beautiful black “elfin saddle” associated with oaks on Observatory Hill, an open space area next to the C. V. Starr East Asian Library. The mushroom is edible, but doesn’t taste good and may be poisonous if not cooked properly. A paper about their finding was published in the November 2014 issue of Mycologia.

“So far only 11 other species have been described from campus,” said Nguyen, who is now a postdoctoral scholar at the University of Minnesota. “The last time this happened was in 1985.”

The Berkeley campus serves as the “type locality” for the new species. “Type localities have elevated scientific value, because they are where the representative specimen was found,” said Nguyen. The finding illustrates the importance of retaining open space and healthy vegetation on Cal’s 1,232-acre urban campus, the researchers said.

Warmer, Drier Climate Altering California’s Forests

Albert Wieslander’s photo of French Lake and English Mountain shows a large area of barren and semi-barren-oak that today is thick with smaller growth. PHOTO: Marian Koshland Biosciences Library

Drought is reshaping California’s forests, according to a study that compared forest surveys conducted by Albert Wieslander ’14 in the 1920s and ’30s with recent U.S. Forest Service data.

The density of large trees has declined in all regions of California, with decreases of up to 50 percent in the Sierra Nevada highlands, the south and central coast ranges, and Northern California, the study found. “Based on our data, water stress helps to explain the decline of large trees,” said study leader Patrick McIntyre, the manager of biodiversity data for the California Department of Fish and Wildlife, who began the research as an environmental science, policy, and management (ESPM) postdoctoral fellow. “Areas experiencing declines in large-tree density also experienced increased water stress since the 1930s.” At the same time, the density of less-thirsty smaller trees is on the rise.

Co-author David Ackerly, professor of integrative biology, said that stressed forests and the loss of large trees could exacerbate the global carbon situation, especially since many are hoping that forests will soak up more and more fossil fuel emissions. “There’s no question that if you are losing large trees, you are losing the standing carbon in the forest,” he said.

The findings suggest that increased temperatures and changing water availability may lead to large-scale changes in forest composition throughout western North America.

Mass Animal Die-Offs on the Rise

Large numbers of dead sunfish and largemouth bass in April 2014 following a severe winter on Wintergreen Lake, Kalamazoo County, Mich. PHOTO: Gary Mittelbach

Mass die-offs of birds, fish, and marine invertebrates have increased in frequency every year over the past seven decades, according to a study co-led by ESPM associate professor Stephanie Carlson. Mass die-offs—when more than 90 percent of a population dies within a short period of time—are still rare and fall short of extinction, but the effects are devastating, and the events are often tied to human activity.

“This is the first attempt to quantify patterns in the frequency, magnitude, and cause of such mass kill events,” Carlson said.

Overall, disease was the primary culprit, accounting for 26 percent of the mass die-offs. Direct effects tied to humans, such as environmental contamination, caused 19 percent of the mass kills. Toxicity triggered by biological events such as algae blooms accounted for a significant proportion of the deaths, and processes directly influenced by climate—including weather extremes, thermal stress, oxygen stress, and starvation—collectively contributed to about 25 percent of the mass mortality events. The most severe events were those with multiple causes, the study found.

The study, published January 12 in the Proceedings of the National Academy of Sciences, and co-led by Yale and the University of San Diego, suggests that in addition to monitoring physical changes such as shifts in temperature and precipitation patterns, it is important to document the biological response to regional and global environmental change. The researchers highlighted ways to improve such documentation, including the possible use of citizen science.

APP CHAP: Arthur Bart-Williams, BS ‘88 Engineering updated the forestry faculty– designed tree tour as a smartphone app. It was released in March. PHOTO: Courtesy of Arthur Bart-Williams


Arthur Bart-Williams, BS ‘88 Engineering updated the forestry faculty– designed tree tour as a smartphone app. It was released in March. See The Big Picture. PHOTO: Courtesy of Arthur Bart-Williams

Trouble on Top of the World


Why would the entire Himalayan village of Kumik pick up and move three kilometers away? The short answer is drought—the village’s one stream has dried up. The long answer is tied to a complex web of climate warming, pollution, and a developing economy, and is the subject of Fire and Ice, a new book by freelance writer Jonathan Mingle, MS ’09 Energy and Resources Group (ERG).

Ever since Mingle first visited Ladakh, the northernmost region of India, more than a decade ago as a volunteer teacher and farmhand, he’s returned there, or to neighboring Zanskar, nearly every year—as a teacher, a researcher, and, most recently, a writer.

Over time, he started observing changes. He listened to older residents describe the trends of hotter summers, shorter winters, and declining snowfall over their lifetimes. He saw glaciers and permanent snowfields shrinking, causing water stress in more and more communities. Pollution became more visible as particulate matter from diesel-burning vehicles and generators and coke- and kerosene-burning heaters increased along with the region’s population.

His own hacking cough during visits was enough to wake him up to a problem, but an ERG talk on black carbon and methane by School of Public Health professor Kirk Smith sent Mingle headlong into his own investigation.

He soon discovered extensive research connecting the melting snow not only with increased greenhouse gas emissions but also with rising levels of black carbon pollution. It’s a cycle that, if unbroken, could lead to ruinous results for the iconic Himalayan region but, if mitigated successfully—at least in part by solar energy that takes advantage of Ladakh’s 315 sunny days per year—could become a model for other developing countries.

“The Ladakh-Zanskar region has been a laboratory for understanding the feedback loops operating between culture, climate, and economic choices at the household and policy scales, and for understanding the consequences of energy transitions,” Mingle says.

His debut book launches with an endorsement from climate change warrior Bill McKibben, who mentored Mingle as part of a science journalism fellowship at Middlebury College. (See Mingle’s interview with E. O. Wilson)

Eat Your Legumes


The farmers who introduced Missoula, Mont., native Liz Carlisle to the revolution taking place deep in her home state’s grain belt ranged from lefty liberals to fundamentalist Christians. But they shared a common plight: Years of drought and costly chemicals had damaged their bottom line and their soil, and threatened their family farms.

Carlisle, PhD ’15 Geography, a postdoctoral fellow at the Center for Diversified Farming Systems, first encountered the farmers while working for U.S. Senator Jon Tester. They were disparagingly called “weed farmers” by Tester’s more conservative constituents because of the messy, low-lying appearance of the plants they raised: organic lentils.

As Carlisle notes in her book, Lentil Underground, the legumes were a natural for Montana’s water-stressed landscape. When there’s no water, the plants neither wither nor bolt—they simply pause their growth cycle. So they don’t require irrigation. On top of that, they preserve nitrogen in the soil, fertilizing themselves and leaving behind healthier soil for the next crop.

By cooperating instead of competing, the group of former conventional farmers built a successful company, Timeless Seeds, and showed doubters, including their own state university, that sustainable farming was both possible and profitable.

Carlisle, who studied with Michael Pollen, is herself part of the colorful cast of characters she paints in the book: Before arriving at UC Berkeley, she spent several years as a professional country singer. As she gigged her way across the country and chatted with farmers after shows, she learned that the “amber waves of grain” she sang about didn’t live up to their hype.

Carlisle implanted herself in the community of Timeless Seeds farmers across four years of dissertation research, and through their story she lays out a workable vision for sustainable agriculture in the age of climate change. (See NewsMakers)

Ping, You Have Water

Chris Hyun, left, observes as men gather to fix a broken water line in Bangalore, India. PHOTO: Courtesy of Chris Hyun

Many of the 9.9 million people in Bangalore, India, never know when they’ll turn on the tap and find water flowing. Water is scarce and rationed. Each household gets about 4.5 hours of running water every other day—but when, and if, it will run can be unpredictable. While high-income households can afford tanks that automatically turn on when the water does, in low-income households, women devote countless hours each week to waiting for and storing water.

ERG graduate student Christopher Hyun is examining how the people of Bangalore can get more reliable and timely information about when and how long they’ll have water each day. “In the developed world, we’re used to just turning the water on and it’s there. We don’t know how it got there,” says Hyun.

The project was prompted by the work in that region of tech start-up Nextdrop, whose founders include UC Berkeley alumni. Nextdrop developed a text-messaging system to communicate with the service workers who manually open and close the valves controlling water flow, then alert residents when water is coming. The research, led by Alison Post, assistant professor of political science and global metropolitan studies, and Isha Ray, ERG associate professor, is examining the effectiveness of the system.