PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Polar bears unlikely to thrive on land-based foods

2015-04-01
(Press-News.org) ANCHORAGE, Alaska -- A team of scientists led by the U.S. Geological Survey found that polar bears, increasingly forced on shore due to sea ice loss, may be eating terrestrial foods including berries, birds and eggs, but any nutritional gains are limited to a few individuals and likely cannot compensate for lost opportunities to consume their traditional, lipid-rich prey -- ice seals.

"Although some polar bears may eat terrestrial foods, there is no evidence the behavior is widespread," said Dr. Karyn Rode, lead author of the study and scientist with the USGS. "In the regions where terrestrial feeding by polar bears has been documented, polar bear body condition and survival rates have declined."

The authors detail their findings in a review article in Frontiers in Ecology and the Environment. The scientists noted that over much of the polar bear's range, terrestrial habitats are already occupied by grizzly bears. Those grizzly bears occur at low densities and are some of the smallest of their species due to low food quality and availability. Further, they are a potential competitor as polar bears displaced from their sea ice habitats increasingly use the same land habitats as grizzly bears.

"The smaller size and low population density of grizzly bears in the Arctic provides a clear indication of the nutritional limitations of onshore habitats for supporting large bodied polar bears in meaningful numbers," said Rode. "Grizzly bears and polar bears are likely to increasingly interact and potentially compete for terrestrial resources."

The study found that fewer than 30 individual polar bears have been observed consuming bird eggs from any one population, which typically range from 900 to 2000 individuals. "There has been a fair bit of publicity about polar bears consuming bird eggs. However, this behavior is not yet common, and is unlikely to have population-level impacts on trends in body condition and survival," said Rode.

Few foods are as energetically dense as marine prey. Studies suggest that polar bears consume the highest lipid diet of any species, which provides all essential nutrients and is ideal for maximizing fat deposition and minimizing energetic requirements. Potential foods found in the terrestrial environment are dominated by high-protein, low-fat animals and vegetation. Polar bears are not physiologically suited to digest plants, and it would be difficult for them to ingest the volumes that would be required to support their large body size.

"The reports of terrestrial feeding by polar bears provide important insights into the ecology of bears on land," said Rode. "In this paper, we tried to put those observations into a broader context. Focused research will help us determine whether terrestrial foods could contribute to polar bear nutrition despite the physiological and nutritional limitations and the low availability of most terrestrial food resources. However, the evidence thus far suggests that increased consumption of terrestrial foods by polar bears is unlikely to offset declines in body condition and survival resulting from sea ice loss."

INFORMATION:

The review article was developed by researchers at the USGS, Washington State University, and Polar Bears International.

The USGS is leading studies of polar bear response to sea ice loss through its Changing Arctic Ecosystems Initiative. Current studies include examination of polar bear nutritional and behavioral ecology, linked to population-level consequences.

For further information, visit the USGS Polar Bear Program.



ELSE PRESS RELEASES FROM THIS DATE:

Night owls face greater risk of developing diabetes than early risers

2015-04-01
Washington, DC--Night owls are more likely to develop diabetes, metabolic syndrome and sarcopenia than early risers, even when they get the same amount of sleep, according to a new study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism. The study examined the difference between night and morning chronotypes, or a person's natural sleep-wake cycle. Staying awake later at night is likely to cause sleep loss, poor sleep quality, and eating at inappropriate times, which might eventually lead to metabolic change. "Regardless of lifestyle, ...

BPA exposure during pregnancy linked to mothers' future diabetes risk

2015-04-01
Washington, DC--Exposure to the endocrine-disrupting chemical bisphenol A during pregnancy may raise a mother's susceptibility to weight gain and diabetes later in life, according to a new animal study published in the Endocrine Society's journal Endocrinology. A chemical used to manufacture plastics and epoxy resins, bisphenol A (BPA) is found in a variety of consumer products, including plastic bottles, food cans and cash register receipts. The U.S. Centers for Disease Control and Prevention have estimated that more than 96 percent of Americans have BPA in their bodies. BPA ...

Broad Institute-MIT team identifies highly efficient new cas9 for in vivo genome editing

2015-04-01
Cambridge, Mass. April 1, 2015-- A collaborative study between researchers from the Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, and the National Center for Biotechnology Information of the National Institutes of Health (NIH-NCBI) has identified a highly efficient Cas9 nuclease that overcomes one of the primary challenges to in vivo genome editing. This finding, published today in Nature, is expected to help make the CRISPR toolbox accessible for in vivo experimental and therapeutic applications. Originally discovered in bacteria, the CRISPR-Cas9 ...

Longer DNA fragments reveal rare species diversity

2015-04-01
Many microbes cannot be cultivated in a laboratory setting, hindering attempts to understand Earth's microbial diversity. Since microbes are heavily involved in, and critically important to environmental processes from nutrient recycling, to carbon processing, to the fertility of topsoils, to the health and growth of plants and forests, accurately characterizing them, as a basis for understanding their activities, is a major goal of the Department of Energy (DOE). One approach has been to study collected DNA extracted from the complex microbial community, or the metagenome, ...

Ebola planning created need for unprecedented preparedness in hospitals

2015-04-01
NEW YORK (April 1, 2015) - Hospitals and health systems preparing for and treating patients with Ebola Virus Disease (EVD) in the fall of 2015 faced unexpected challenges for ensuring safety of staff, patients and the community. The experiences are detailed in two studies published online in Infection Control & Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America (SHEA). In a case study of the care of two patients with confirmed or suspected EVD at the National Institutes of Health (NIH) Clinical Center's Special Clinical Studies Unit, ...

How we hear distance: Echoes are essential for humans to perceive how far away a sound is

2015-04-01
Mammals are good at figuring out which direction a sound is coming from, whether it's a rabbit with a predator breathing down its neck or a baby crying for its mother. But how we judge how far away that sound is was a mystery until now. Researchers from UConn Health report in the 1 April issue of the Journal of Neuroscience that echoes and fluctuations in volume (amplitude modulation) are the cues we use to figure the distance between us and the source of a noise. "This opens up a new horizon," says Duck O. Kim, a neuroscientist at UConn Health. Researchers have long ...

Drop the bounce test: A common battery test often bounces off target

Drop the bounce test: A common battery test often bounces off target
2015-04-01
Don't throw away those bouncing batteries. Researchers at Princeton University have found that common test of bouncing a household battery is not actually an effective way to check a battery's charge. "The bounce does not tell you whether the battery is dead or not, it just tells you whether the battery is fresh," said Daniel Steingart, an assistant professor of mechanical and aerospace engineering and of the Andlinger Center for Energy and the Environment. The battery bounce test, popularized in online videos, shows that fully charged batteries bounce very little ...

Interview blues -- anxious, slow talkers often do not get the job

2015-04-01
Researchers offer a few tips for those who are worried that their nerves might stand between them and acing their next job interview. Stop worrying about how much you might blush or your nervous tics, and focus more on being warm, friendly and assertive. The advice comes from Amanda Feiler and Deborah Powell of the University of Guelph in Canada, who carefully watched what anxious people do during an interview, and how others respond to them. Their findings are published in Springer's Journal of Business and Psychology. People who are anxious going into an interview often ...

NASA covers Super Typhoon Maysak's rainfall, winds, clouds, eye

NASA covers Super Typhoon Maysaks rainfall, winds, clouds, eye
2015-04-01
NASA's fleet of satellites and instruments in space have covered Super Typhoon Maysak's rainfall, winds, clouds and an astronaut about the International Space Station captured a close-up photo of the storm's eye. On April 1 at 01:35 UTC (March 31 at 9:35 p.m. EDT), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Terra satellite captured a stunning view of Super Typhoon Maysak in the Northwestern Pacific Ocean. The MODIS image clearly showed its eye and bands of powerful thunderstorms circling the eye, and wrapping into it from the east ...

Suicide not associated with deployment among US military personnel

2015-04-01
Deployment to Operation Enduring Freedom or Operation Iraqi Freedom was not associated with suicide in a study of more than 3.9 million U.S. military personnel in the Air Force, Army, Marine Corps and Navy, according to an article published online by JAMA Psychiatry. The suicide rate among active duty U.S. military members has increased in the last decade and research on the potential effect of deployment to Operation Enduring Freedom (OEF) or Operation Iraqi Freedom (OIF) is limited, according to the study background. Mark A. Reger, Ph.D., of Joint Base Lewis-McChord, ...

LAST 30 PRESS RELEASES:

Scientists trace origins of now extinct plant population from volcanically active Nishinoshima

AI algorithm based on routine mammogram + age can predict women’s major cardiovascular disease risk

New hurdle seen to prostate screening: primary-care docs

MSU researchers explore how virtual sports aid mental health

Working together, cells extend their senses

Cheese fungi help unlock secrets of evolution

Researchers find brain region that fuels compulsive drinking

Mental health effects of exposure to firearm violence persist long after direct exposure

Research identifies immune response that controls Oropouche infection and prevents neurological damage

University of Cincinnati, Kent State University awarded $3M by NSF to share research resources

Ancient DNA reveals deeply complex Mastodon family and repeated migrations driven by climate change

Measuring the quantum W state

Researchers find a way to use antibodies to direct T cells to kill Cytomegalovirus-infected cells

Engineers create mini microscope for real-time brain imaging

Funding for training and research in biological complexity

The Journal of Nuclear Medicine Ahead-of-Print Tip Sheet: September 12, 2025

ISSCR statement on the scientific and therapeutic value of human fetal tissue research

Novel PET tracer detects synaptic changes in spinal cord and brain after spinal cord injury

Wiley advances Knowitall Solutions with new trendfinder application for user-friendly chemometric analysis and additional enhancements to analytical workflows

Benchmark study tracks trends in dog behavior

OpenAI, DeepSeek, and Google vary widely in identifying hate speech

Research spotlight: Study identifies a surprising new treatment target for chronic limb threatening ischemia

Childhood loneliness and cognitive decline and dementia risk in middle-aged and older adults

Parental diseases of despair and suicidal events in their children

Acupuncture for chronic low back pain in older adults

Acupuncture treatment improves disabling effects of chronic low back pain in older adults

How interstellar objects similar to 3I/ATLAS could jump-start planet formation around infant stars

Rented e-bicycles more dangerous than e-scooters in cities

Ditches as waterways: Managing ‘ditch-scapes’ to strengthen communities and the environment

In-situ molecular passivation enables pure-blue perovskite LEDs via vacuum thermal evaporation

[Press-News.org] Polar bears unlikely to thrive on land-based foods