Moose Management- Predators

Garry Gamble

In an odd sign of the times, an astute Star Tribune reader recently observed, “There are roughly twice as many Critical Habitat ‘moose’ [license] plates in Minnesota than there are moose in the state.”

Predation has a lot to do with declining moose numbers, and research would certainly appear to corroborate this fact.

The study of predator / prey relationships, however, is one of the most controversial aspects of moose population dynamics. Regrettably, sociopolitical considerations often dictate what is reported (and believed), let alone what is done – or not done.

Wildlife biologists have long established that predators such as wolves, black bears, grizzly bears, and brown bears have preyed on large ungulates – like the moose – ever since their arrival as part of Nature’s food chain.

In northeastern Minnesota the two primary predators moose combat for survival are wolves and black bears.

In 1958, L. David Mech, who has become one of the foremost authorities on wolves in the world, initiated a study on Isle Royale. Research that continues today as the longest continuous investigation of a large predator / prey system in North America. The whole island being dominated by two animals: wolves and moose.

Michigan State Biologist Rolf Peterson, who has been scrutinizing the relationship between the moose and wolves on the island for nearly half a century, considers Isle Royale a perfect place to study the balance between predator and prey. In a 2014 documentary, produced as part of Smithsonian’s Earth series, Peterson established, “There are more moose per square mile on Isle Royale than anywhere else in North America – 7.74 moose per square mile.”

During their annual winter sojourn on the island, scientists Rolf Peterson and John Vucetich conducted aerial surveys and estimated the moose population at 1,600. “It could double over the next three to four years unless more wolves arrive soon,” they said. (thought-provoking ...)

“Moose swam to the island early in the 20th century. They went through boom and bust without any predators on the island. The population shot up to the thousands, gobbling up huge swaths of the forest, almost destroying the island.”

“What to do about the over abundant moose population was the prominent wildlife management controversy of the entire national park system in the 1940s. That went away as soon as the wolf showed up in the 1950s, thanks to a particularly cold winter when Lake Superior froze solid and the wolves strolled over from Canada to an ‘all you can eat moose buffet,’” explained Peterson.

“The Isle Royale experience clearly demonstrates that moose will thrive in the presence of reduced predation,” observed noted columnist Ron Schara in a February 2017 newspaper commentary.

“While Minnesota’s case is more complex, the state’s moose are prey to a historically high wolf population. In one Minnesota wolf study area, the number of wolves roaming the north is the highest it’s been in 40 years,” Schara wrote.

Here’s a sobering statistic that supports Schara’s comments: Alaska is the only U.S. state with a higher population of wolves than Minnesota. Areas of Alaska, such as the Nelchina Basin, approximately two hours northeast of Anchorage, have reached record wolf densities as high as 6.0 per 100 square miles. According to the Minnesota DNR website, Minnesota’s current density is approximately 10.0 per 100 square miles.

Minnesota’s wolf range has expanded from a 12,000 square mile area in the 1950s to over 27,000 square miles. As of 2016, the population is estimated to be 2,278, which certainly exceeds the federal delisting goal of 1,250 - 1,400. These data suggest that the population has fully recovered and special concern status should no longer be necessary …you would think?

Research biologists Charles C. Schwartz and Albert W. Franzmann (authors of the book Ecology and Management of the North American Moose) found from their studies and those of others, “Where predator populations [in our case wolves] are near carrying capacity, a peak moose population would decline at a greater rate and lower density. The opposite effect was postulated for a predator free environment.” (I suggest you re-read this last paragraph.)

In a 2014 Star Tribune news article, Dr. Mech said he believes “wolves are playing a bigger role in the decline of northeast Minnesota moose than originally believed.”

Star Tribune writer Josephine Marcotty related in a Feb. 7, 2016 newspaper article, “No question, biologists say, that bringing down wolf numbers could help moose. Wolves long ago saturated all the territory that’s available to them in the state, and they’re hungry.”

In Newfoundland, there are no wolves. The Newfoundland wolf is thought to have become extinct sometime in the early 1920s, according to biologist Shane Mahoney.

Without whitetail deer to introduce tick-borne diseases, apex predators like the wolf, and with plenty of new-growth forests, Newfoundland has become home to more than 10 percent of North America’s moose population; approximately 120,000 moose on the island – one of the most concentrated moose densities in North America at approximately 2.86 moose per square mile.

Ron Schara verbalizes the opinion of many outdoor enthusiasts when he asserts, “Wolf management in Minnesota continues to be snarled in state politics and federal courts, where judges, not biologists, dictate wolf and moose relationships.”

It is apparent judges, sympathetic to “howling” advocacy groups, can’t see the forest for the “gray fur.” Maybe it’s time we just collar a bunch of wolves with judges so they can find out first-hand what wolves are eating.

Observation: If we are serious about keeping our moose here in Minnesota, those entrusted with the responsibility for managing our wildlife populations need to establish a healthy balance between predator and prey.

Next week: The influence of weather on the moose population.

Former Cook County Commissioner Garry Gamble is writing this ongoing column about the various ways government works.

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