Featured Research

from universities, journals, and other organizations

Global Warming Could Be Affecting Wolf-Moose Balance

Date:
March 5, 2004
Source:
Michigan Technological University
Summary:
Wolves are up and moose are down this spring at Isle Royale National Park, the home of a 46-year study of predators and their prey. Researchers suspect that a global warming trend may be behind the shift.

Wolves are up and moose are down this spring at Isle Royale National Park, the home of a 46-year study of predators and their prey. Researchers suspect that a global warming trend may be behind the shift.

Related Articles


The moose population has slid to 750 on this Lake Superior wilderness island park, down from 900 last year and 1,100 in 2002. In the meantime, the number of wolves has seesawed upward over the past decade and is now up to 29, as many as the park has seen since 1980 and 11 more than last year.

What's bad for moose has been good for the wolves, and moose throughout North America have been hit hard by warmer temperatures that began in 1998 with El Nino and never let up, according to Professor Rolf Peterson of Michigan Technological University, who has lead the study of Isle Royale's wolves and moose for 34 years.

"What we think is happening is that wolves are cashing in on moose vulnerability that's been induced by a warmer climate," Peterson said.

The moose population has been stressed by higher temperatures, particularly the drought of 1998 and then warm fall of 2001. "Moose can't feed in the summertime if it's too hot," Peterson said. "They have a big fur coat on, and they can't sweat. They just sit in the shade or in the water."

When moose don't eat enough in summer, they can become weak, sickly and easy prey for wolves during the winter.

And heat precipitates another blight for the big herbivores: ticks.

"Warm weather in spring and fall leads to ticks the following winter, and ticks can kill moose," Peterson said. A single moose can be host to tens of thousands at a time, several per square inch, and each tick can suck up about a cubic centimeter of blood. Rather than browse, the moose scratch themselves against trees or bite their hair out trying to remove the parasites. Weight and blood loss often prove such a handicap that the moose don't survive.

As the moose population struggles against the heat and ticks, the wolves have thrived, largely because it's been easier for them to bring down their biggest prey. "The wolves are killing about twice as many moose as they did last year," Peterson says, which allows them to maintain their peak population.

Initially, researchers didn't know what warmer temperatures would mean for Isle Royale's wolves and moose.

"In this region the change has involved warmer winters, especially in the late 1990s and early years of this century," Peterson said. "We couldn't anticipate the effect for moose, because warmer winters mean less snow and more tree growth, which helps them.

"But it also leads to more ticks, and it impacts their feeding. With two pluses and two minuses, there was no way to forecast how it would come out in the wash. But it looks like it might be to the detriment of moose."

As to what has been causing the warmer temperatures, Peterson cites climate models presented in the journal Science that suggest that greenhouse gases may be the culprit. While researchers do not have proof that increasing levels of carbon dioxide and other gases are warming the Earth's atmosphere, the best computer models of climate can only account for such higher temperatures if greenhouse gases are included.

Peterson's study is funded by the National Park Service, the National Science Foundation, and Earthwatch.


Story Source:

The above story is based on materials provided by Michigan Technological University. Note: Materials may be edited for content and length.


Cite This Page:

Michigan Technological University. "Global Warming Could Be Affecting Wolf-Moose Balance." ScienceDaily. ScienceDaily, 5 March 2004. <www.sciencedaily.com/releases/2004/03/040305073726.htm>.
Michigan Technological University. (2004, March 5). Global Warming Could Be Affecting Wolf-Moose Balance. ScienceDaily. Retrieved April 20, 2015 from www.sciencedaily.com/releases/2004/03/040305073726.htm
Michigan Technological University. "Global Warming Could Be Affecting Wolf-Moose Balance." ScienceDaily. www.sciencedaily.com/releases/2004/03/040305073726.htm (accessed April 20, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Monday, April 20, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Newsy (Apr. 20, 2015) Five years on, the possible environmental impact of the Deepwater Horizon spill includes a sustained die-off of bottlenose dolphins, among others. Video provided by Newsy
Powered by NewsLook.com
Pee-Power Toilet to Light Up Disaster Zones

Pee-Power Toilet to Light Up Disaster Zones

Reuters - Innovations Video Online (Apr. 20, 2015) Students and staff are being asked to use a prototype urinal to &apos;donate&apos; urine to fuel microbial fuel cell (MFC) stacks that generate electricity to power lighting. The developers hope the pee-power technology will light toilet cubicles in refugee camps, where women are often at risk of assault in poorly lit sanitation areas. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Undersea Quake Shakes Taiwan

Raw: Undersea Quake Shakes Taiwan

AP (Apr. 20, 2015) A strong undersea earthquake struck between Taiwan and southern Japan on Monday, sparking a house fire that killed a person outside of Taiwan&apos;s capital. (April 20) Video provided by AP
Powered by NewsLook.com
Five Years Later, the BP Oil Spill Is Still Taking Its Toll

Five Years Later, the BP Oil Spill Is Still Taking Its Toll

AFP (Apr. 20, 2015) On April 20, 2010, an explosion and fire on the Deepwater Horizon rig in the Gulf of Mexico started the biggest oil spill in US history. BP recently reported the Gulf is recovering well, but scientists paint a different picture. Duration: 02:36 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins