“Alberta bears have remarkably diverse diets,” said Dr. Mark Boyce, biological sciences professor at the U of A and co-author on the study. “They’ll eat just about anything.”
Ants, fruits, moose and plants are a few staples of the Alberta grizzly bear’s diet. This new research study was the most comprehensive examination of grizzly bear foods ever conducted in Canada. Using global positioning system (GPS) radiotelemetry technology and analyzing 665 feces collected from 18 grizzly bears over a period of three years, the scientists found that the bears packed a lot of activity into 24 hours. The research was recently published in the “Journal of Mammalogy.”
Much is known about what bears in mountainous areas eat but little is known of the diets of grizzly bears living in boreal forests also used by humans. As well, this new research looked at five different activities the bears use to find food—whether it feeds on flowers, insects, fruits, digs for plants or kills other animals, specifically ungulates.
The diverse diets of the Alberta grizzly bear helps cushion them against climate change and other vagaries of the environment, said Boyce. Specifically, the research team found that the bears living in the foothills are effective predators on moose and deer. They are especially good at killing moose calves during the difficult spring period when other foods like berries are not yet available, said Boyce. Mountain bears are largely vegetarian, by comparison.
The scientists identified 40 different food items, examining each for seasonal patterns of use and differences among mountain and foothills environments. Digging the root of sweet vetch plants dominated early spring diets, while preying on ungulates—or hooved animals--was greatest during late spring, although the timing varied between foothill and mountain bears. Moose were the most common ungulate eaten by the bear (83 per cent), especially newborns (54 per cent), with white-tailed and mule deer (16 per cent) and elk (1 per cent) more minor in comparison. Rodents, insects (primarily ants), and birds were also consumed. Green vegetation dominated early summer diets and as fruit ripened in early August, berries such as soopolallie and mountain huckleberry were added to the bears’ menu. The scientists also learned that most of the activity of the east slopes bears takes place in the daytime, especially morning and the evening. This is in contrast to bears living in spots where more frequent contact with humans take place, such as Banff National Park where most bear activity has become nocturnal.
Although the bears are filling up on these different food sources, being so near to highways and roads is dangerous for the animals.
“Bears are eating substantial amounts of clover and alfalfa, which are common roadside plantings,” said Boyce. “Because these roadside plantings are attractive to bears, this can put the bears at risk of contact with humans. Nearly all new roads being constructed in the province are built by industry, either for timber harvest or oil and gas development.
“We should encourage industry to avoid using such attractive food items when planting in ditches and roadsides. It would be much better to use native grasses and other native plants to stabilize road banks and ditches. Most bear deaths occur near roads and we want to avoid attracting bears to areas near roads.”
Phoebe Dey | EurekAlert!
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A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
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Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
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Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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