Monday, November 10, 2014

Don't blame moose decline on wolves

  • Article by: MAUREEN HACKETT
  • Updated: November 7, 2014
Look to humans, other causes in both species’ struggle to survive.
Photo: Brian Peterson, DML - Star Tribune


Are wolves to blame for fewer Minnesota moose?” (Nov. 2) suggested that wolves play a large role in the decline of the moose population. Although wolves are indeed a predator of moose, there is no evidence that wolves are the reason our Minnesota moose population is facing such hard times.

Moose populations are down throughout their usual range, including areas with no wolf population. For example, in New Hampshire, the moose population has declined by over 41 percent since the 1990s. There is no wolf presence in New Hampshire.

Wolves are the real wildlife managers of our forests, and wolves and moose have coexisted for tens of thousands of years. Moose need wolves to keep them and the whitetail deer population moving while they eat, to allow enough trees to grow above browsing height, which keeps their food sources (trees) available to them. Wolves do this by choosing the sickest and oldest as prey. Wolves control their own numbers through their complex social bonds and their limited reproduction. (A wolf pack usually has only one litter per year.)

We humans likely have caused the problems for moose by habitat encroachment and climate change, leading to infestations of ticks and decreasing plants for their food.

The Department of Natural Resources (DNR) is rightly troubled about moose dying in higher numbers; in fact, DNR officials are concerned about the toll that climate change, parasites and disease have been taking. The parasite b. tenuous is a serious issue; it targets the brains of the infected animals. Michelle Carstensen of the DNR said the number of moose that have been killed by wolves in the DNR’s moose mortality study is not what is concerning, but it is the level of moose mortality from all causes.

What the DNR has previously reported is large tick infestations on moose causing severe anemia (not enough red blood cells). When animals do not have enough red blood cells, they cannot gain weight because they cannot carry enough oxygen and nutrition throughout their bodies. This makes them vulnerable to infections and unable to tolerate normal and expected environmental stressors. Weak animals give birth to weak calves.

A significant number of moose did not survive after being given GPS collars, and were found to be very weak and thin with little fat. Something other than wolves is the culprit, and wolves may be one of the few positive natural forces to offset whatever it may be, which is likely related to the overall ecosystem health.

Wolves still struggle to survive, just like the moose. Our Minnesota wolf population had been stable since 1998 after coming back from near extinction in the 1970s. Now, after one hunting season, the population is 25 percent below 2008 levels. The DNR calls this stable. But one disease outbreak can wipe out 80 percent of the wolves.

Continuing annual recreational wolf hunting and trapping is keeping the wolf population on the edge of collapsing. We are killing random wolves and disrupting their pack system that they rely on for survival. Wolves that lose pack mates experience social and physical struggles that can cause unpredictable problems for them and for the environment.

It is clear that the moose population is struggling to survive. However, the wolf is not the cause of this struggle. Both animals have, can, and should coexist in Minnesota.

Maureen Hackett is president and founder of Howling for Wolves.