Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Young Arctic muskoxen better at keeping warm than scientists thought

24.08.2009
A new study finds that young muskoxen conserve heat almost as well as adults, a finding that runs contrary to a longstanding assumption among scientists that young animals should be more vulnerable in extreme cold.

The study, by biologist Adam Munn from the University of Sydney, Australia, will be published in the forthcoming issue of Physiological and Biochemical Zoology.

Surviving freezing winters is tough for any animal, but it is generally assumed to be tougher on the young. Young animals theoretically should have a harder time holding heat because they have larger ratios of surface area to body volume, meaning more of their body mass is directly exposed to the cold. That theory appeared to hold true for muskoxen—shaggy vegetarians that look a bit like buffalo, but are actually more closely related to sheep. Scientists have previously reported high death rates for muskox calves during especially cold winters in their arctic habitats.

But in measuring heat loss in adult and young muskoxen, Munn and his research team found that the cold itself might not be the culprit.

"To our surprise, we found that the smaller calves were not more thermally stressed than larger adults," said Munn said.

Munn and his team observed a population of muskoxen at the University of Alaska's R.G. White Large Animal Research Facility in Fairbanks. They used infrared sensing equipment to measure heat loss from the body surface of animals in contact with cold air and the frozen ground. Munn tested the muskoxen during winter foraging, when the animals were the most directly exposed to the cold.

The researchers found that both calves and adults sacrificed only two to six percent of their daily energy intake to heat loss during foraging bouts, even when temperatures dipped to minus 50 Celsius (minus 58 Fahrenheit).

"This suggests that any thermoregulatory constraints associated with a small body size may not be as important for calf survival as previously thought," Munn says. "This is important because calf mortality in muskoxen and other large arctic herbivores has been variously linked with severe winters, which are expected to increase in number and severity with current climate trends.

"However, we present evidence that thermal costs per se may not be driving calf mortalities in muskoxen."

That doesn't mean climate change presents no risk to muskoxen or other large herbivores. They still face danger from food shortages and other ecological disturbances, Munn says.

Muskoxen have a variety of ways to fight heat loss. They are insulated by thick fur called qiviut, and they likely have the ability to direct blood away from their extremities in cold weather.

"Overall, our work shows that predicting a species' responses to climate change requires detailed understanding of all aspects of their physiological ecology, and particularly for how this changes throughout life," Munn says.

Adam J. Munn, Perry S. Barboza and Jon Dehn, "Sensible Heat Loss from Muskoxen (Ovibos moschatus) Feeding in Winter: Small Calves Are Not at a Thermal Disadvantage Compared with Adult Cows." Physiological and Biochemical Zoology, September/October 2009.

Physiological and Biochemical Zoology has presented current research in environmental, adaptational, and comparative physiology and biochemistry since 1928. PBZ is co-edited by Dr. Kathleen Gilmour of the University of Ottawa and Dr. Patricia Schulte of the University of British Columbia. They assumed editorial duties in July of this year.

Kevin Stacey | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Studies and Analyses:

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

nachricht Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>