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Categories: Biology: Zoology, Ecology: Research

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More time stranded on land means greater risk of starvation for polar bears, a new study indicates. During three summer weeks, 20 polar bears closely observed by scientists tried different strategies to maintain energy reserves, including resting, scavenging and foraging. Yet nearly all of them lost weight rapidly: on average around 1 kilogram, or 2.2 pounds, per day. Some have speculated that polar bears might adapt to the longer ice-free seasons due to climate warming by acting like their grizzly bear relatives and either rest or eat terrestrial food. The polar bears in this study tried versions of both strategies -- with little success.

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Scientists examined hundreds of birds in museum collections and discovered a suite of feather characteristics that all flying birds have in common. These 'rules' provide clues as to how the dinosaur ancestors of modern birds first evolved the ability to fly, and which dinosaurs were capable of flight.

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Researchers find deforestation accounts for about 10 percent of global human-made mercury emissions. While it cannot be the only solution, they suggest reforestation could increase global mercury uptake by about 5 percent.

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Engineers have studied how insects navigate, for the purpose of developing energy-efficient robots.

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Beaked whales are among the least studied mammals in the world. Now, a new study reveals surprising information about the Baird's beaked whale species.

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Analysis reveals imported earthworm species have colonized large swaths of North America, and represent a largely overlooked threat to native ecosystems. The researchers warn of the need to better understand and manage the invaders in our midst.

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Scientists have discovered that nighttime air pollution -- coming primarily form car exhaust and power plant emissions -- is responsible for a major drop in nighttime pollinator activity. Nitrate radicals (NO3) in the air degrade the scent chemicals released by a common wildflower, drastically reducing the scent-based cues that its chief pollinators rely on to locate the flower. The findings show how nighttime pollution creates a chain of chemical reactions that degrades scent cues, leaving flowers undetectable by smell. The researchers also determined that pollution likely has worldwide impacts on pollination.

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Scientists have discovered a tiny worm species that infects and kills insects. These worms, called nematodes, could control crop pests in warm, humid places where other beneficial nematodes are currently unable to thrive.

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A newly discovered neural circuit mediates between navigational brain cells, acting as a sort of mental steering wheel.

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Researchers report that replacing 50% of animal products with alternative proteins by 2050 could free up enough agricultural land to generate renewable energy equivalent in volume to today's coal-generated power while simultaneously removing substantial CO2 from the atmosphere.

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A new study explores whether the plentiful, fibrous byproduct of CBD production holds potential promise as a nutritious, efficiency-boosting feed ingredient for the dairy sector

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New research reveals that denser, and more sheltered, kelp forests can withstand serious stressors amid warming ocean temperatures.

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Extreme events wipe out entire forests, dramatically eliminating complex ecosystems as well as local communities. Researchers have become quite familiar with such attention-grabbing events over the years. They know less, however, about the more common moderate-severity disturbances, such as relatively small fires, ice storms, and outbreaks of pests or pathogens.

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The rivers of Australia, which once flowed across its now dry interior, used to host a range of bizarre animals -- including a sleek predatory lobe-finned fish with large fangs and bony scales. The newly described fossil fish discovered in remote fossil fields west of Alice Springs has been named Harajicadectes zhumini by palaeontologists.

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An experiment spanning more than two decades has found that removal of apex predators from an ecosystem can create lasting changes that are not reversed after they return -- at least, not for a very long time. The study challenges the commonly held belief that the reintroduction of wolves to Yellowstone National Park restored an ecosystem degraded by their absence.

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The workings of the ultrasonic warning sounds produced by the wings of a species of moth have been revealed.

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There was an increase in the number of unprovoked shark attacks worldwide and an uptick in fatalities in 2023 compared to the previous year. A scientific database of global shark attacks, confirmed 69 unprovoked bites in 2023. Although this is higher than the most recent five-year average of 63 attacks, the data remain consistent with long-term trends.

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Retroviruses are viruses that multiply by incorporating their genes into the genome of a host cell. If the infected cell is a germ cell, the retrovirus can then be passed on to the next generation as an 'endogenous' retrovirus (ERV) and spread as part of the host genome in that host species. In vertebrates, ERVs are ubiquitous and sometimes make up 10 per cent of the host genome. However, most retrovirus integrations are very old, already degraded and therefore inactive -- their initial impact on host health has been minimized by millions of years of evolution. A research team has now discovered a recent case of retrovirus colonization in a rodent from New Guinea, the white-bellied mosaic-tailed rat.

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New study reveals how gene expression shapes the diverse smelling and tasting abilities of different fly species. Most genes are surprisingly stable, but thousands have evolved to create unique olfactory landscapes. Sex differences in sensing are widespread and involve specific cell types in key tissues. The study provides insights into the evolution of sensory systems in general, with potential implications for understanding human olfaction.

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New research sheds light on tiny plankton, which measure less than 0.02mm in diameter but can make up more than 70% of the plankton biomass found in the ocean.