April 4, 2014: Moose thrive, wolves don't on Isle Royale

  • Article by: LEE BERGQUIST , Milwaukee Journal Sentinel
  • Updated: August 9, 2014 - 10:16 PM

The number of wolves, however, is near an all-time low.

hide

Biologists say the moose population on Isle Royale has been increasing at an annual rate of more than 20 percent in each of the past three years.

Photo: ROLF PETERSON • Michigan Technological University,

CameraStar Tribune photo galleries

Cameraview larger

Wildlife researchers who spent the winter on an island in Lake Superior report that Isle Royale’s moose population is booming while wolf numbers remain near an all-time low.

Moose have roughly doubled in the past three years, Michigan Technological University biologists Rolf Peterson and John Vucetich said in a blog post.

The two spend seven weeks every winter on the 45-mile-long island monitoring wolves and moose — both by foot and by air — in one of world’s longest continuous studies of predator-prey relationships.

That relationship has tipped clearly in favor of moose, whose population the biologists said has been increasing at an annual rate of more than 20 percent in each of the past three years.

The latest population figures and a host of other data will be released probably next week, Peterson said. A year ago in their last report, Peterson and Vucetich counted 975 moose from their winter observations.

That means moose numbers in the latest count could increase to more than 1,100.

The picture, however, is far different for wolves. The population now stands at nine. The lowest number ever recorded since research began in the 1950s was the eight that were counted last winter.

The declining population has sparked a debate about human intervention: Should wolves be imported to the island to boost the genetic pool?

Elk have been reintroduced to northwestern Wisconsin, and turkeys and whooping cranes were brought back to the state.

Isle Royale is different because, as an island, it is virtually a closed ecosystem.

In Wisconsin, the results of reintroduction efforts have been mixed: Turkeys have flourished while elk and whooping cranes have struggled.

Peterson and Vucetich favor a genetic rescue, and the National Park Service, which manages the island, is studying the issue.

This winter was marked by prolonged cold — the average minimum temperature was below zero on 33 of 48 days, the scientists reported.

The cold and record ice cover in the Great Lakes raised the possibility wolves from the mainland would venture onto the island. That has happened in the past but has been less common in recent decades. An over-the-ice migration last occurred in 1997 when a male, known as Old Gray Guy, walked across and provided the island’s wolves with a genetic shot in the arm. Numbers rose, and so did the wolves’ efficiency in killing moose.

But instead of new arrivals this winter, a 5-year-old female, Isabelle, who had never found a mate, wandered over the pack ice and was found dead on Feb. 8 on the Grand Portage Indian Reservation in northeastern Minnesota.

A necropsy revealed the wolf had been killed by a pellet, fired from a low-power pellet gun, that hit her between two ribs and severed an artery. An investigation by the park service and the Minnesota Department of Natural Resources found no violation of wildlife laws.

Now with so few wolves, the biologists say those remaining suffer from a lack of genetic diversity and a growing inability to hunt. Only six moose were killed over a 47-day period this winter, the biologists reported.

“All told this amounted to an estimated predation rate of only about 2 percent …,” Peterson and Vucetich wrote. “This was the third year in a row that wolf predation has been so low, almost absent.”

While the biologists are at a loss to explain it, the declining genetic vigor has “reduced the ability of wolves on Isle Royale to effectively kill moose.”

  • get related content delivered to your inbox

  • manage my email subscriptions

Click here to send us your hunting or fishing photos – and to see what others are showing off from around the region.

ADVERTISEMENT

Kansas City - J. Vargas 7:07 PM
San Francisco - R. Vogelsong
Detroit 10/26/14 8:30 AM
Atlanta
Buffalo 10/26/14 12:00 PM
NY Jets
St. Louis 10/26/14 12:00 PM
Kansas City
Houston 10/26/14 12:00 PM
Tennessee
Minnesota 10/26/14 12:00 PM
Tampa Bay
Seattle 10/26/14 12:00 PM
Carolina
Baltimore 10/26/14 12:00 PM
Cincinnati
Miami 10/26/14 12:00 PM
Jacksonville
Chicago 10/26/14 12:00 PM
New England
Philadelphia 10/26/14 3:05 PM
Arizona
Oakland 10/26/14 3:25 PM
Cleveland
Indianapolis 10/26/14 3:25 PM
Pittsburgh
Green Bay 10/26/14 7:30 PM
New Orleans
Washington 10/27/14 7:30 PM
Dallas
New Orleans 10/30/14 7:25 PM
Carolina
Buffalo 3:00 PM
San Jose
Boston 6:00 PM
Toronto
NY Rangers 6:00 PM
Montreal
New Jersey 6:00 PM
Ottawa
Dallas 6:00 PM
NY Islanders
Detroit 6:00 PM
Philadelphia
Chicago 7:00 PM
St. Louis
Pittsburgh 7:00 PM
Nashville
Tampa Bay 7:00 PM
Minnesota
Florida 8:00 PM
Arizona
Washington 9:00 PM
Calgary
So Florida 17 FINAL
Cincinnati 34
Troy 13 FINAL
South Alabama 27
BYU 30 FINAL
Boise State 55
(6) Oregon 59 FINAL
California 41
North Texas 21 3rd Qtr 10:30
Rice 24
UAB 3 3rd Qtr 6:03
Arkansas 38
Rutgers 10 3rd Qtr 7:05
(16) Nebraska 28
Maryland 0 3rd Qtr 8:38
Wisconsin 31
Texas 0 3rd Qtr 2:53
(11) Kansas State 13
Minnesota 17 3rd Qtr 6:02
Illinois 21
Memphis 34 3rd Qtr 8:45
SMU 7
North Carolina 21 3rd Qtr
Virginia 24
San Jose St 10 2nd Qtr 6:35
Navy 14
Northern Ill 14 2nd Qtr 1:45
Eastern Mich 7
(25) UCLA 7 1st Qtr 11:50
Colorado 0
Akron 0 1st Qtr 11:45
Ball State 3
Massachusetts 6 1st Qtr 9:32
Toledo 0
Ohio U 0 1st Qtr 11:30
Western Mich 0
Ga Southern 0 1st Qtr 11:15
Georgia State 3
Kent State 1:30 PM
Miami-Ohio
Oregon State 2:30 PM
Stanford
Fla Atlantic 2:30 PM
(23) Marshall
Louisiana Tech 2:30 PM
Southern Miss
(1) Miss State 2:30 PM
Kentucky
Georgia Tech 2:30 PM
Pittsburgh
(22) West Virginia 2:30 PM
Oklahoma State
Texas Tech 2:30 PM
(10) TCU
Michigan 2:30 PM
(8) Michigan State
Boston College 2:30 PM
Wake Forest
Central Mich 2:30 PM
Buffalo
Vanderbilt 3:00 PM
Missouri
Old Dominion 3:00 PM
Western Ky
UNLV 3:00 PM
Utah State
Temple 4:00 PM
UCF
(15) Arizona 5:00 PM
Washington St
Texas-El Paso 6:00 PM
TX-San Antonio
Wyoming 6:00 PM
Colorado State
Syracuse 6:00 PM
(21) Clemson
Texas State 6:00 PM
ULM
(3) Ole Miss 6:15 PM
(24) LSU
(4) Alabama 6:30 PM
Tennessee
So Carolina 6:30 PM
(5) Auburn
(13) Ohio State 7:00 PM
Penn State
(20) USC 9:00 PM
(19) Utah
(14) Arizona State 9:45 PM
Washington
Nevada 10:59 PM
Hawaii
(2) Florida State 10/30/14 6:30 PM
Louisville
Troy 10/30/14 6:30 PM
Ga Southern
Cincinnati 10/31/14 7:00 PM
Tulane
Tulsa 10/31/14 7:00 PM
Memphis
Purdue 11/1/14 2:00 AM
(16) Nebraska
(17) Oklahoma 11/1/14 2:00 AM
Iowa State
Oklahoma State 11/1/14 2:00 AM
(11) Kansas State
(10) TCU 11/1/14 2:00 AM
(22) West Virginia
Texas 11/1/14 2:00 AM
Texas Tech
Northwestern 11/1/14 2:00 AM
Iowa
Maryland 11/1/14 2:00 AM
Penn State
Air Force 11/1/14 10:30 AM
Army
ULM 11/1/14 11:00 AM
Texas A&M
Duke 11/1/14 11:00 AM
Pittsburgh
Wisconsin 11/1/14 11:00 AM
Rutgers
Rice 11/1/14 11:00 AM
FIU
(18) East Carolina 11/1/14 11:00 AM
Temple
UCF 11/1/14 11:00 AM
Connecticut
Boston College 11/1/14 11:30 AM
Virginia Tech
North Carolina 11/1/14 11:30 AM
Miami-Florida
Washington 11/1/14 12:00 PM
Colorado
Central Mich 11/1/14 12:00 PM
Eastern Mich
Western Mich 11/1/14 1:30 PM
Miami-Ohio
Western Ky 11/1/14 2:00 PM
Louisiana Tech
NC State 11/1/14 2:00 PM
Syracuse
Texas State 11/1/14 2:00 PM
New Mexico St
Virginia 11/1/14 2:30 PM
Georgia Tech
BYU 11/1/14 2:30 PM
Middle Tennessee
Indiana 11/1/14 2:30 PM
Michigan
Florida 11/1/14 2:30 PM
(9) Georgia
Georgia State 11/1/14 2:30 PM
Appalachian St
Kentucky 11/1/14 3:00 PM
Missouri
Kansas 11/1/14 3:00 PM
(12) Baylor
Houston 11/1/14 3:00 PM
So Florida
(20) USC 11/1/14 3:30 PM
Washington St
Arkansas State 11/1/14 4:00 PM
Idaho
South Alabama 11/1/14 4:00 PM
Louisiana
New Mexico 11/1/14 4:30 PM
UNLV
UAB 11/1/14 6:00 PM
Fla Atlantic
(5) Auburn 11/1/14 6:00 PM
(3) Ole Miss
Arkansas 11/1/14 6:00 PM
(1) Miss State
Old Dominion 11/1/14 6:00 PM
Vanderbilt
Colorado State 11/1/14 6:00 PM
San Jose St
Stanford 11/1/14 6:30 PM
(6) Oregon
Tennessee 11/1/14 6:30 PM
So Carolina
Southern Miss 11/1/14 7:00 PM
Texas-El Paso
(7) Notre Dame 11/1/14 7:00 PM
Navy
Illinois 11/1/14 7:00 PM
(13) Ohio State
(15) Arizona 11/1/14 9:30 PM
(25) UCLA
California 11/1/14 9:30 PM
Oregon State
San Diego St 11/1/14 9:30 PM
Nevada
Wyoming 11/1/14 9:45 PM
Fresno State
(19) Utah 11/1/14 10:00 PM
(14) Arizona State
Utah State 11/1/14 10:00 PM
Hawaii
Los Angeles 1:30 PM
Seattle
D.C. 3:00 PM
Montreal
Toronto FC 6:30 PM
New England
Portland 7:30 PM
FC Dallas
Colorado 9:00 PM
Vancouver FC
Montreal 23 FINAL
Ottawa 17
Saskatchewan 27 FINAL
Calgary 40
Hamilton 3:00 PM
Toronto
Brt Columbia 6:00 PM
Winnipeg
Hamilton 10/31/14 6:30 PM
Ottawa
Winnipeg 11/1/14 3:00 PM
Calgary
Brt Columbia 11/1/14 6:00 PM
Edmonton
Toronto 11/2/14 11:00 AM
Montreal
Connect with twitterConnect with facebookConnect with Google+Connect with PinterestConnect with PinterestConnect with RssfeedConnect with email newsletters

ADVERTISEMENT

ADVERTISEMENT

ADVERTISEMENT

ADVERTISEMENT

question of the day

Poll: Should the lake where the albino muskie was caught remain a mystery?

Weekly Question

ADVERTISEMENT

 
Close