[Home]
[Full version]
There's no such thing as a picky grizzly bear
Feb 22 ,General Science
A new University of Alberta study, which tracked eating habits of grizzly bears living in the Alberta foothills, sheds some light on the animal's varied diet and their activity pattern.
"Alberta bears have remarkably diverse diets," said Dr. Mark Boyce, biological sciences professor at the U of A and co-author of the study, recently published in the Journal of Mammalogy. "They'll eat just about anything."
Little is known of the diets of grizzly bears living in boreal forests also used by humans. This new research study is the most comprehensive examination of grizzly bear diet ever conducted in Canada. Using global positioning system (GPS) radiotelemetry technology and analyzing 665 feces samples collected from 18 grizzly bears over a period of three years, the scientists also found that the bears packed a lot of activity into 24 hours.
The new research looked at five different activities the bears use to find food - whether it feeds on flowers, insects and plants or kills other animals - specifically ungulates.
The diverse diets help cushion the grizzlies against climate change and other vagaries of the environment, said Boyce. Specifically, the research team found that bears living in the foothills are effective predators of moose and deer. They are especially good at killing moose calves during the difficult spring, when other foods 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. The root of sweet vetch plants dominated early spring diets, while preying on ungulates, was greatest during late spring, although the timing varied between foothill and mountain bears. Moose are 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 (one per cent), minor in comparison.
Rodents, insects and birds were also consumed. Green vegetation dominated early summer diets and as fruit ripened in early August, berries were added to the 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.
Boyce said food sources so near to highways and roads are 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."
Source: University of Alberta
Related stories:
Grizzly bears feast on diverse diet
There’s no such thing as picky grizzly bears—they’ll eat almost anything they can find. A new University of Alberta study that tracked food habits of the Alberta grizzly bear living in the foothills sheds some light on the animal’s varied diet and their activity pattern.
Reducing roads could boost bear population
Alberta's scant grizzly bear population could grow by up to five per cent a year if fewer logging roads are built in the animals' habitat, according to University of Alberta researchers.
International experts collect alpine fungi in Beartooth Mountains of Montana
Armed guards once kept polar bears away while Cathy Cripps collected mushrooms and fungi on the island of Svalbard between Norway and the North Pole. Another time, Cripps encountered musk-oxen while gathering fungi in Greenland.
Probing Question: How do antioxidants work?
Blueberries, pomegranates, green tea and dark chocolate -- these are just some of the antioxidant-rich "superfoods" found in almost any supermarket today. As well as improving our general health, there is growing evidence that diets high in antioxidants may confer some protection against a long list of chronic diseases, including Alzheimer's disease, cancer and even HIV. Given their increasing popularity, the fundamental question bears asking: What exactly are antioxidants, and how do they work in our bodies?
Cave bears from the Carpathians as omnivorous as modern bears
Rather than being gentle giants, new research reveals that Pleistocene cave bears, a species which became extinct 20,000 years ago, ate both plants and animals and competed for food with the other contemporary large carnivores of the time such as hyaenas, lions, wolves, and our own human ancestors. The research is published this week in the
Proceedings of the National Academy of Sciences (PNAS).
Study of bear hair will reveal genetic diversity of Yellowstone's grizzlies
Locks of hair from more than 400 grizzly bears are stored at Montana State University, waiting to tell the tale of genetic diversity in the Yellowstone Ecosystem.
Humans unknowing midwives for pregnant moose
When it’s time for moose to give birth in the Greater Yellowstone Ecosystem, they head to where it is safest from predators – namely closer to people, according to a new study by the Wildlife Conservation Society.
Climate change isolates Rocky Mountain butterflies
Expanding forests in the Canadian Rocky Mountains are slowly isolating groups of alpine butterflies from each other, which may lead to the extinction of the colourful insects in some areas, says a new study from the University of Alberta.
[Home]
[Full version]