03 Dec 2013:
Microplastic Pollution Harms
Worms at Bottom of Food Chain, Study Finds
As plastic trash accumulates in ocean ecosystems, it may be damaging worms and other sensitive marine life at the bottom of the food chain, scientists report. Two British studies found
that microplastics — tiny remnants, less than 5 mm in diameter, from the breakdown of plastic trash — made seafloor worms eat
Beach sediments churned by a lugworm
less and transferred pollutants from the plastics to the worms. Because they ate less, the worms had less energy to invest in important functions
such as growth, reproduction, and churning sediments, one of their most important roles in the ocean ecosystem. The worms also absorbed harmful chemicals from the debris
, including hydrocarbons, antimicrobials, and flame retardants, researchers said. Lugworms, often called the "earthworms of the sea," are considered an indicator species because they feed on ocean floor sediments. Microplastics have been accumulating in those sediments since the 1960s, and, although each particle is nearly invisible, taken together microplastics are the most abundant form of solid-waste pollution on the planet.
02 Dec 2013:
Poachers Killed 22,000
Elephants in Africa Last Year, Group Says
Poachers slaughtered 22,000 elephants in 27 African countries last year, according to a new report
. Officials with The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and two conservation groups said that 15,000 elephant
Rhett A. Butler/Mongabay
A herd in Namibia
deaths from poaching were officially reported in Africa and that another 7,000 deaths went unreported. Although that number is a slight decrease from the 2011 estimate of 25,000 poaching deaths, CITES officials warn that poaching rates are far too high and could soon lead to local extinctions. Africa, which is currently home to roughly 500,000 elephants, could lose a fifth of its elephant population over the next 10 years, CITES says. "The estimated poaching rate of 7.4 percent in 2012 remains at an unsustainably high level, as it exceeds natural population growth rates (usually no more than 5 percent)," the report says.
29 Nov 2013:
Wide Mangrove Destruction
Is Documented Along Coast of Myanmar
Rapid agricultural expansion destroyed nearly two-thirds of the mangrove forests
in Myanmar’s Ayeyarwady Delta between 1978 and 2011, increasing the region’s vulnerability to cyclones and typhoons, according to a new study. Using remote sensing imagery
and field data, researchers from Myanmar and Singapore said that the dense mangrove cover in the Ayeyarwady Delta declined from 2,623 square kilometers to 1,000 square kilometers in that 33-year period. The main cause was agriculture expansion and the researchers said that if rates of destruction continue at their current pace the delta’s mangroves could be completely deforested by 2026. Reporting in the journal Global Environmental Change
, the scientists said the loss of mangroves in the Ayeyarwady Delta could put the region at greater risk of major storms such as Cyclone Nargis, which killed 138,000 people in Myanmar in 2008. But the researchers said the destruction could be slowed if Myanmar creates coastal protected areas.
26 Nov 2013:
Updated Conservation List
Finds Forest Giraffes on Brink of Extinction
In an updated list released today, the International Union for the Conservation of Nature (IUCN) noted some significant successes and failures in global wildlife
Okapi, or forest giraffe
conservation efforts. A major success story is the leatherback sea turtle
, whose Atlantic population has recovered enough for the species to be considered only vulnerable, rather than critically endangered. The IUCN attributed the leatherback rebound to better protection of nesting beaches and reduced fisheries bycatch. The updated Red List contains more somber news, though, for the blue-tongued forest giraffe
, the national symbol of the Democratic Republic of the Congo. The striped-legged forest giraffe, a species of okapi, is on the brink of extinction due mainly to the long, ongoing civil war in that country, which has led to increased poaching and loss of habitat. The Red List's ranks of threatened species have grown by 352 species since this summer
, Mongabay reports, with roughly 21,000 species now listed as threatened.
Fish 2.0: A Contest Seeks to Foster
A More Sustainable Seafood Industry
Twenty pioneers in the sustainable seafood business climbed a stage at Stanford University in November in an effort to woo the judges at the Fish 2.0 contest
Click to Enlarge
HM Terry Co.
The winning project connects fishermen directly to customers.
with proposals on how to change the way the U.S. catches, distributes, and markets fish. A business competition at heart, Fish 2.0 brought together entrepreneurs and investors to spur innovation in the tradition-bound seafood industry. Competitors's proposals ranged from converting waste at fish processing plants to expanding a Hawaiian network of aquaponic growers, who raise fish and vegetables together in tanks, into the developing world. One proposal aimed to create a data system to track catches in real time, enabling fisheries managers to hold the line on harvests. Contestants headed home with more than $75,000 in prize money. Read more.
19 Nov 2013:
Pollution From Plastic Trash
May Make Tiny Island a Superfund Site
The U.S. Environmental Protection Agency plans to study whether plastic pollution on a small island in the Pacific Ocean is severe enough to warrant listing it as a Superfund clean-up site
. Tern Island, a 25-acre strip of land about 500 miles northwest of the Hawaiian island
Oahu, is home to millions of seabirds, sea turtles, and the endangered Hawaiian monk seal. The U.S.-based Center for Biological Diversity asked the EPA to add the entire Northwestern Hawaiian Islands and parts of the so-called Great Pacific Garbage Patch
to the list of federal Superfund sites due to extreme marine debris pollution, but the agency has only agreed to undertake an environmental study on Tern Island. The island is awash with debris ranging from plastic water bottles and bits of plastic to discarded fishing gear and home appliances. Studies have shown the trash can take a heavy toll on wildlife — seabirds, for example, often ingest bits of plastic after mistaking them for food and eventually die of starvation. The EPA study is the first step of a potentially years-long process to determine if the island qualifies for listing under the 1980 Superfund law.
14 Nov 2013:
U.S. Crushes Six Tons
Of Illegally Trafficked Elephant Ivory
The U.S. Fish and Wildlife Service
(FWS) destroyed six tons of elephant ivory
today that field agents seized over the past 25 years. The U.S. Ivory Crush event, which took place in Denver, Colorado, marked the first time
the FWS has destroyed large quantities of ivory. The move was an attempt to send a clear message that the U.S. will not tolerate illegal ivory trafficking and the toll it's taking on elephant populations in Africa and Asia, the FWS said. Seized ivory is usually kept as evidence for prosecuting traffickers, then later used for education and training, but the FWS had accumulated far more ivory than it needs. The ivory that was crushed included full tusks, carved tusks, jewelry, carvings, and other objects, and came from at least 2,000 poached elephants, the FWS estimates.
13 Nov 2013:
Plastic Debris in Ocean
Has Spawned a 'Plastisphere' of Organisms
The plastic debris that litters the world's oceans has developed its own unique and diverse microbial ecosystem, researchers report. The microscopic community, which scientists dubbed the "plastisphere,"
includes more than 1,000 species of algae, bacteria, microscopic plants, symbiotic microbes, and possibly even pathogens, the researchers say in Environmental Science & Technology
. Some of the plastisphere microbes, many of which had never before been documented, contain genes that could help break down hydrocarbons, indicating the microbes may play a role in degrading the debris, the research shows. Plastic trash is the most abundant type of debris in the ocean, inflicting harm on fish, birds, and marine mammals that are entangled by it or ingest it. Until now, researchers hadn't looked at microbes living on the debris, which make up a sort of artificial "microbial reef," one of the scientists said
Interview: Using Robots to Unlock
Mysteries of CO2 and the Oceans
As climate change accelerates, scientists are focusing on the key role the world’s oceans play in absorbing half the planet’s carbon dioxide. But the precise mechanisms
Robotic Wave Glider
by which the oceans remove carbon from the atmosphere and the consequences for marine life remain poorly understood. That has led Tracy Villareal, a professor of marine science at the University of Texas at Austin, to devote his research to diatom phytoplankton. To better understand how these tiny organisms mitigate climate change, Villareal has become a pioneer in the use of a wave- and solar-powered ocean-going robot, known as the Wave Glider. In an interview with Yale Environment 360
, Villareal discusses why unlocking the secrets of diatoms is critical to understanding climate change and how deploying robots will revolutionize marine science. “There are all sorts of wild robotic systems under development,” he says. Read the interview.
06 Nov 2013:
Disturbed Tropical Forests
Are Slow to Regain Plant Biodiversity
In tropical forests that are regrowing after major disturbances, the ability to store carbon recovers more quickly than plant biodiversity, researchers from the U.K. have found
. However, even after 80 years, recovering forests store less carbon than old-growth
A regrowing tropical forest in Brazil
forests, according to a study published in the Proceedings of the Royal Society B.
This is likely because regenerating forests are often dominated by small, fast-growing trees and it may take centuries for larger trees, which hold more carbon, to become established, according to scientists from the Center for Ecology & Hydrology and Bournemouth University, who studied more than 600 recovering tropical forests. Tree species that are hallmarks of old-growth forests were rare or missing in the regrowing forests, the study showed. Since regenerating forests are often located far from old-growth forests and surrounded by farmland, it may be difficult for animals to move seeds between the forests, which may account for the lower plant biodiversity, researchers said.
23 Oct 2013:
Endangered Asiatic Cheetahs
Are Spotted by Iranian Conservationists
Iranian conservationists have spotted a rare Asiatic cheetah with four cubs, offering hope that the large cats can be pulled back from the brink of extinction. Only 40 to 70 Asiatic cheetahs exist today, all in Iran. Over the
weekend, conservationists with the Persian Wildlife Heritage Foundation (PWHF) spotted the five cheetahs in Khar Turan national park in northern Iran. "In the past year or so that we closely monitored Turan, we never spotted a family, especially female cheetahs with cubs," Delaram Ashayeri, project manager at PWHF, told the Guardian
. "It shows Asiatic cheetahs are surviving, breeding cubs are managing to continue life. It's good news against a barrage of bad news about these animals." Iranian conservationists have been involved in a decade-long campaign to protect the cheetahs and educate indigenous people living near them. But sanctions imposed by Western nations over Iran's nuclear program have hampered these efforts, making it difficult to secure international funding and equipment, such as camera traps.
17 Oct 2013:
Animals May Play Significant
Role in Carbon Cycling, Researchers Say
Wildlife may play a more important role in the global carbon cycle than researchers have previously given it credit for, according to a study
from an international group of scientists. Although models generally include
Muskoxen in Alaska
carbon cycling by plants and microbes, they often ignore the ways animals contribute to the process. That's a mistake, says Oswald Schmitz, an ecologist at Yale who led the study, because the actions of wildlife can affect carbon cycling through "indirect multiplier effects." For example, the massive loss of trees in North America triggered by the pine beetle outbreak has caused a net carbon change on scale with British Columbia's current fossil fuel emissions, the researchers reported in Ecosystems
. And in the Arctic, where about 500 gigatons of carbon is stored in permafrost, large grazing mammals like caribou and muskoxen can help maintain the grasslands that have a high albedo and thus reflect more solar energy. "We're not saying that managing animals will offset these carbon emissions," Schmitz said. "What we're trying to say is the numbers are of a scale where it is worthwhile to start thinking about how animals could be managed to accomplish that."
11 Oct 2013:
Agricultural Ammonia Emissions
Threatening U.S. National Parks, Study Finds
Ammonia emissions from agricultural fertilizers are threatening sensitive ecosystems in U.S. national parks, a study led by Harvard researchers
has found. Thirty-eight national parks are seeing nitrogen deposition levels at or above the threshold for ecological damage,
Great Smoky Mountains N.P.
the study says. In natural ecosystems, excess nitrogen can disrupt nutrient cycling in soil
, cause algal overgrowth, and make aquatic environments acidic. While some of that nitrogen comes in the form of nitrogen oxides (NOx) from power plants and vehicle exhaust, existing air quality regulations and new clean energy technologies are helping reduce NOx emissions. Ammonia emissions from agricultural operations, however, are expected to climb as demand for food and biofuels surges. Daniel Jacob, who led the study, said that because ammonia is volatile, only 10 percent of the nitrogen makes it into the food, with much of it escaping through the atmosphere and being deposited across the landscape. According to the report, published in Atmospheric Chemistry and Physics
, hardwood trees, such as those shown above, are most sensitive to excess nitrogen in eastern temperate forests, while in western national parks lichens appear to suffer first.
07 Oct 2013:
Nutrient Recycling by Sponges
Is Vital in Sustaining Reefs, Study Says
Sponges are the unsung heroes of coral reefs, helping the vibrant ecosystems thrive in the marine equivalent of a desert, a Dutch team working in the Caribbean has found
. Scientists had long questioned how reefs, some
of the most productive communities on earth, were able to survive in low-nutrient tropical seas. Bacteria help recycle some nutrients, but the so-called "microbial loop" can't account for the high rates of carbon, nitrogen, and phosphorous recycling needed to maintain a coral reef, researchers say. Sponges fill that void by drawing in plankton and organic matter expelled by the corals and shedding cells that other reef organisms ingest as food, the researchers report in Science
. The "sponge loop," as the Dutch team calls the process, recycles 10 times more organic material than bacteria do and produces as many nutrients as all other primary producers in a coral reef combined, they say.
01 Oct 2013:
Small Rainforest Predators
Are Photographed and Studied in Gabon
The west African country of Gabon is known for its gorillas, elephants, and other large animal species, but a recent study
has shed light on little-known rainforest predators that could face increasing pressure from the
bushmeat trade. Using camera traps, bushmeat surveys, and DNA analyses, researchers from Panthera, the Wildlife Conservation Society, and other groups completed the first-ever survey of 12 small carnivore species throughout the country. The study found two species — the common slender mongoose and the Cameroon cusimanse — that hadn't been found in Gabon before, and it documented an extended range for the Egyptian mongoose. “It appears that these species are widespread and not currently threatened, but the proximity of many small carnivores to human settlements and the growing bushmeat trade could potentially impact these populations," said Wildlife Conservation Society researcher Fiona Maisels, who co-authored the study. "These new findings will help inform future management."
26 Sep 2013:
Major Initiative Announced
To Help Curb Elephant Poaching in Africa
The Clinton Global Initiative and 16 conservation organizations have announced that they are investing $80 million
over three years to stem the epidemic of elephant poaching in Africa, which has surged recently due to increasing demand for ivory in Asia. The Partnership to Save Africa's Elephants, which includes the governments of seven African nations, will fund programs that scale up anti-poaching enforcement, combat trafficking at ports and markets with more enforcement and harsher penalties, and curb the demand for illegal ivory with ad campaigns aimed at consumers in China, Vietnam, and other nations. "We cannot hope to reverse the dramatic decline in elephant populations without addressing all three parts of the problem," said Patrick Bergin, CEO of the African Wildlife Foundation.
25 Sep 2013:
More Than 80 Elephants Dead
From Cyanide Poisoning in Zimbabwe Park
Poachers poisoned watering holes with cyanide in Zimbabwe's Hwange National Park, killing 81 elephants
in the latest wave of slayings to supply the trade in illegal ivory. The cyanide, poured into remote watering
Hwange National Park
holes in the park, also killed smaller animals and vultures that ate the poisoned carcasses. Park rangers arrested nine alleged poachers after following them to a cache of ivory tusks hidden in the park. The elephant death toll of 81 includes 41 carcasses found earlier this month following another cyanide poisoning incident in Hwange park. Zimbabwe's new environment minister, Saviour Kasukuwere, has pledged to make jail penalties for poachers harsher. Elephant and rhino poaching in Africa
has accelerated in recent years due to increasing Asian demand for ivory and rhino horn, which is used in traditional medicines, even though it has no proven medicinal properties. Officials estimate tens of thousands of elephants are being slaughtered each year in the worst wave of poaching in decades.
12 Sep 2013:
Migration of Trees Is
Not Keeping Pace with Warming
Most tree species in the U.S. aren't migrating northward as rapidly as predicted in response to climate change, a new study says
. Looking at 65 species across
Kilmer Forest, North Carolina
31 eastern states, the team found no consistent, northward migration of tree species, as many other climate studies have predicted. Rather than shifting northward by dispersing seeds to cooler climates, the researchers found, tree species are responding by speeding up their life cycles. "Most trees are responding through faster turnover," says lead scientist James Clark
of Duke University, "meaning they are staying in place but speeding up their life cycles in response to longer growing seasons and higher temperatures." The results appear in Global Change Biology
Counterpoint: Two Scientists Offer
A Dissenting View on Ascension Island
Ecologists Daniel Simberloff, of the University of Tennessee, and Donald Strong, of the University of California, Davis, have written a critical appraisal of a recent Yale Environment 360
article by Fred Pearce about Ascension Island. In their critique, the two scientists contend that Pearce failed to accurately describe what has occurred on the island and misrepresented the science of restoration ecology. Read more
03 Sep 2013:
Crop Pests Migrate Poleward
Due to Global Warming, Study Says
Global warming has been driving crop pests toward the North and South poles at a rate of 1.7 miles per year, according to new research from the U.K. Looking at the
Stem rust (Puccinia graminis fungus)
distribution of 612 crop pests over the past 50 years, the researchers found a strong correlation between warming global temperatures and increased ranges for the pests. “If crop pests continue to march polewards as the Earth warms, the combined effects of a growing world population and the increased loss of crops to pests will pose a serious threat to global food security,” said Daniel Bebber, a biologist at the University of Exeter who led the study published in Nature Climate Change
. Crop pests — which include insects as well as bacteria, fungi, viruses, and nematodes — destroy 10 to 16 percent of the world's crops each year, or enough food to feed nine percent of the population, scientists estimate.
27 Aug 2013:
Mexican Gray Wolves
Granted Increased Protection in the U.S.
The U.S. government has agreed to expand the territory
where a small population of Mexican gray wolves in the southwestern U.S. can be protected and reintroduced.
Mexican gray wolf
Under a pair of agreements with the non-profit Center for Biological Diversity, the U.S. Fish & Wildlife Service also has consented to a plan under which Mexican gray wolves that cross the U.S.-Mexico border and establish territories in Arizona and New Mexico will no longer be captured by U.S. authorities. The agency will also start releasing captive Mexican gray wolves into Gila National Forest and allow them to establish territories throughout much of New Mexico and Arizona. That rule, set to be finalized by January 2015, significantly expands the habitat for a beleaguered population of about 75 Mexican gray wolves
in those states. Wildlife ecologists have been advocating for such measures, saying increased protections and expanded territories are essential to the recovery of the Mexican wolf population, but states in the region have strongly opposed such an expansion.
21 Aug 2013:
Thai Monkeys May Abandon
Stone Tools Due to Human Disruptions
Human disturbances in Thailand’s Laem Son National Park may be causing Burmese long-tailed macaques to abandon their use of stone tools, say researchers studying the primates
. The only monkeys in Asia to use
stone tools — and one of only three non-human primates worldwide to do so — these Burmese macaques have learned to use coastal rocks to crack the hard-shelled crabs, snails, and oysters that make up their diet. Habitat loss to rubber and oil palm farming, competition with humans for food sources, and threats from domestic dogs are forcing the macaques to change their foraging habits, researchers from Singapore’s Nanyang Technological University report. The monkeys are also showing signs of acclimating to humans and becoming dependent on human food sources.
20 Aug 2013:
Google ‘Street View’ Will
Document Changes to World's Coral Reefs
Marine biologists are teaming up with Google to photograph detailed 360-degree panoramas of coral reefs around the globe. Using technology similar to
Google’s Street View feature, users will be able to survey coral reefs much like they might scope out a city block. The project, Google Street View Oceans
, has already surveyed a 150-kilometer stretch of the Great Barrier Reef and is now working on reefs in the Caribbean
. "Only 1 percent of humanity has ever dived on a coral reef, and by making the experience easily accessible the survey will help alert millions of people around the world to the plight of coral reefs," said Ove Hoegh-Guldberg, a marine biologist at the University of Queensland in Australia who is leading the survey. Image recognition software will log the distribution and abundance of marine organisms, and the researchers hope "citizen scientists" viewing the reefs will help assess other key measures of reef health.
15 Aug 2013:
Plants in U.S. Southwest
Moving Higher as the Climate Warms
Numerous plant species on a mountain in the southwestern U.S. are migrating to higher elevations
as the climate gets warmer and drier, according to a new
University of Arizona
An alligator juniper on Mount Lemmon
study. After comparing the results of a recent survey of 27 plants found on Mount Lemmon, a 9,157-foot peak near Tucson, Ariz., with a similar survey conducted in 1963, researchers at the University of Arizona found that three-quarters of the plants have shifted their range “significantly” upslope in the last five decades. In some cases, researchers found that the plants had moved upward by as much as 1,000 feet, into a much narrower elevation range than where the plants existed in the early 1960s. Writing in the journal Ecology and Evolution
, the researchers note that the lowermost boundary for 15 of the species has shifted upslope.
14 Aug 2013:
Bears Using Wildlife Corridors
In Canadian Park, Genetic Tests Show
Genetic testing has revealed that bears in Canada’s Banff National Park routinely cross the bridges and underpasses along the Trans-Canada Highway
, evidence that the ecological corridors provide safe
A grizzly passes through a Banff underpass
passage along a busy roadway that otherwise threatens to fragment wildlife habitat
. Using 420 wire snag “hair traps” and 497 rub trees at 20 crossings to collect hair from passing bears, researchers from Montana State University determined that 15 individual grizzly bears and 17 individual black bears used the passages over a three-year period. According to researchers, those accounted for about 20 percent of the park’s bear populations, suggesting the passageways are providing enough connectivity to maintain a healthy ecosystem for bears and other large mammals. Twenty-five passages were installed in the 1990s
when the government widened a highway that includes a 100-mile stretch bisecting Banff.
13 Aug 2013:
Too Many Urban Beehives
May Do More Harm Than Good, Experts Say
A surge in urban beekeeping may be doing more harm than good to honeybee populations
, according to UK scientists. As the number of rooftop hives increases in cities worldwide
— including London, where there are
A Berlin beekeeper
now 10 hives per square kilometer — two researchers from the University of Sussex warn that too many hives can be detrimental. Writing in The Biologist
, the magazine of the Society of Biology, they suggest that inexperienced beekeepers can create conditions in which there isn’t enough food for their insects. “If there are too many colonies in an area, then the food supply will be insufficient,” Francis Ratnieks, a professor at the university’s Laboratory of Apiculture and Social Insects, told the BBC. “This will mean that colonies do not thrive, and may also affect other species that also visit flowers.”
09 Aug 2013:
Mapping of Monarch Butterfly
Migration Yields Clues About Decline
A comprehensive mapping of the North American migration patterns of the iconic monarch butterfly
could help preserve a species threatened by loss of habitat and food sources
, a team of international
A monarch butterfly
researchers says. In a study conducted across 17 U.S. states and two Canadian provinces, from southern Texas to Alberta, biologists from Canada, the U.S., and Australia tracked the northward migration of the monarchs, documenting five generations in a single breeding season. By analyzing a chemical signature found on the adult butterflies’ wings that reveals their specific birthplace, scientists were able to track the different generations of butterflies as they migrated north to the U.S. Midwest, from which many butterflies then traveled to Alberta. According to Tyler Flockhart, a Ph. D. student at the University of Guelph in Canada and lead author of the study published in the Proceedings of the Royal Society B
, the decline in milkweed and a surge in genetically modified crops might be affecting monarch survival.
05 Aug 2013:
New Deep-Rooted Rice
Shows Greater Resistance to Drought
Japanese scientists say they have developed a rice plant with deeper roots
that could yield a more drought-resistant variety of rice. Writing in the journal Nature Genetics
, a team of scientists describes the discovery of gene that causes a rice strain known as Kinandang Patong, grown in the dry upland of the Philippines, to send longer roots into the soil, allowing the plant to extract water from deeper soil layers. After splicing the gene with a commonly grown rice strain, called IR64, the scientists found that the maximum root depths were more than twice those of the typical plants. After exposing both strains to moderate and severe drought conditions, the researchers found that yields of the standard variety fell significantly in moderate drought conditions and collapsed altogether in severe drought, while the modified strains were not affected by moderate drought and yields declined only 30 percent in severe drought.
01 Aug 2013:
Whales Shown to Flee
From Mid-Frequency Military Sonar
Two new studies show that the use of military sonar can provoke whales to flee
, providing evidence that the naval operations may be a factor in mass strandings of whales and dolphins worldwide. According to one study
A blue whale
most marine mammal strandings related to naval sonar exercises involve beaked whales, a notoriously shy species that responds to noise levels well below those used by the U.S. Navy. Scientists believe the beaked whales may interpret the sonar noises as the sounds of killer whales. A separate study
found that even mid-frequency sonar affected the behavior of blue whales, the largest animals on earth, especially during feeding. After exposing tagged blue whales to simulated military sonar and other mid-frequency sounds, the animals often ceased feeding, increased swimming speeds, and traveled away from the sound. “Noise pollution threatens vulnerable populations, driving them away from areas important to their survival, and at worst injuring or even causing the deaths of some whales and dolphins,” Sarah Dolman of the non-profit group Whale and Dolphin Conservation told the Guardian
30 Jul 2013:
Return of Yellowstone Wolves
Triggers Surge in Grizzly's Prized Berries
The reintroduction of wolves at Yellowstone National Park has caused a cascade of ecological effects that has led to the regrowth of berries
, an important food source for the park’s grizzly bears, scientists say. Writing in the
Journal of Animal Ecology
Yellowstone National Park
Grizzly bear at Yellowstone Park
, scientists from Oregon State University and the University of Washington report that the percentage of fruit found in bear scat has nearly doubled during the month of August in recent years. According to researchers, this reflects a recovery of berry bushes triggered in large part by the wolves, which have reduced overbrowsing by the park’s elk herds. The removal of wolves for most of the 20th century triggered the demise of the park’s young aspen and willow trees, as well as berry-producing shrubs, scientists say. According to the report, berries may be so important to the health of bear populations that their recovery could mean a lifting of the species’ “threatened” status under the Endangered Species Act