The discovery of brown (grizzly) bears feeding on migrating broad whitefish in a stream in Mackenzie Delta region of the Northwest Territories has researchers advising increased care in petroleum extraction and infrastructure development within the area.
In a paper published in the September issue of the journal Arctic, Oliver Barker and Andrew Derocher from the University of Alberta report seeing at least one brown bear engaged in the unusual activity of caching whitefish at Pete's Creek, a small Mackenzie River tributary located between Inuvik and Tuktoyaktuk. While it is well known that brown bears feed on salmon, trout and charr, this is the first scientific reporting of brown bears feeding on whitefish and supports what is recorded from local traditional knowledge.
Each spring since 2003, several bears were outfitted with satellite radio-collars. In October 2007, while conducting a helicopter survey of the bears, the researchers noticed two patches of disturbed ground near Pete's Creek. What they found when they landed surprised them – two caches with whole and partially eaten whitefish.
"My first impression was excitement. My second was apprehension," says Barker, "I don't like being in willow thickets when there are bears nearby."
Realizing their shotgun was in the helicopter, Barker beat a hasty retreat. Once in the air, they did indeed observe a young female nearby. "She was quite fat and shiny. Very roly-poly,'" recalls Barker.
Brown bears in the Mackenzie Delta face several challenges. Not only are food sources scarce, the bears are often active for just five months of the year. This creates extreme pressure for them to find adequate nutrition.
"These bears are real opportunists. They'll take advantage of different food sources," says Barker. This means some will turn to whitefish which are easily available in large numbers when they migrate in the fall. And although bears are omnivores and can exist on mostly vegetarian diets, fish are a better food source because they are rich in protein and fat.
Barker says the fall run of whitefish could be playing a significant role in the diets of some Mackenzie Delta brown bears. He would like to see more research conducted on the bears and their feeding habits, in order to mitigate the impacts of development activities.
"Pete's Creek may be an important but spatially concentrated food source, but we can't put it into context until we know more" says Barker. "It could take a small amount of disturbance in an area like this to disrupt these bears. There is still a lot we don't know about Mackenzie Delta bears, and any development should be mindful of such resources."For media interviews with Oliver Barker:
The mission of the Arctic Institute of North America at the University of Calgary is to advance the study of the North American and circumpolar Arctic and to acquire, preserve and disseminate information on physical, environmental and social conditions in the North. More information can be found at www.arctic.ucalgary.ca
Value from wastewater
16.08.2017 | Hochschule Landshut
Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences