Moose Management Takes Center Stage
Summer 2016
By Dr Patrick Rusz, Director of Wildlife Programs
The U.S. Fish and Wildlife Service recently announced it is investigating whether to add moose in Michigan, Minnesota, Wisconsin and North Dakota to the federal endangered species list. The agency will consider whether the moose in question represent a Midwestern subspecies that is in decline. A 60-day period for public comment will end August 2.
Michigan’s moose population is not what biologists expected when a major effort was launched to restore the species 30 years ago. A population goal of 1,000 animals by the year 2000 was set by the DNR, but was never reached. For this year, the DNR’s official estimates are 323 in the western Upper Peninsula that resulted from transplanting Ontario moose in 1985 and 1987, and about 100 in the eastern U.P.
There is also a currently thriving moose herd on Isle Royale. The estimates for the mainland of Michigan are based on spotting moose from fixed-winged aircraft and applying a “correction factor.” There is no statistically reliable difference in estimates from surveys in 2006, 2007, 2009, 2011, and 2013 for the western U.P. Biologists did observe a decline in the proportion of calves in the population and think that a population decline may have occurred. The recommendation of the state’s Moose Hunting Advisory Council is to allow hunting of moose only if the population maintains a growth rate of three percent or more per year. So, at present moose are not hunted anywhere in Michigan.
In pre-settlement times, moose inhabited all of Michigan except for the southwestern part of the Lower Peninsula. However, moose were probably never abundant in the L.P. By the 1880s moose were gone from the Lower Peninsula and scarce in the U.P. The DNR contends moose may have completely died out from the U.P. and then reestablished through immigration from Ontario. A mid1930s transplant of 63 moose from Isle Royale to various places in the Upper Peninsula was judged as a failure.
The case for a Midwestern subspecies of moose is based on skull characteristics and it’s going to be tough to determine whether Michigan actually has a different moose than say, Ontario. Taxonomic or genetic data will presumably be considered by FWS in its review along with the somewhat questionable history of moose in the U.P.
If Michigan’s moose are considered threatened or endangered under federal law, the real debate will be over what options for “recovery” are reasonable.
Moose populations are affected by numerous factors including some that people will be unable or unwilling to address. In Michigan, two important pieces of the moose puzzle are deer and wolves. The Isle Royale moose population is presently thriving precisely because the island has no deer and no wolves. Deer carry a brain worm that is devastating to moose (and elk) but that doesn’t impact the deer. Moose can thrive with deer only in regions where they don’t occupy the same habitats. In Minnesota, researchers have documented that at least 20 percent of moose die from brain worm and many more are likely made vulnerable to wolves because of the disease. If maintaining moose depends on reducing deer numbers, sound moose management will be a hard sell to the Michigan public. There might be more support for reducing wolf numbers, but that might mean more deer and more brain worm. And there is evidence that the thriving moose population of Isle Royale—without wolves to keep the numbers in check—will fairly soon destroy the balsam fir and other key habitat components on which moose depend.
Some ecologists also think moose management in states like Michigan that are on the southern fringe of the species’ North American range is also being complicated by climate change. One important way that could work is by driving up populations of winter ticks. The tiny parasites can literally suck the life out of moose; researchers in New Hampshire have found more than 100,000 ticks on a single moose. A few mild winters can cause tick populations to soar.
In the face of such challenges, moose management in Michigan will likely remain very difficult. The FWS’s endangered species listing process is sure to bring related issues to the forefront over the next year or two.
By Dr Patrick Rusz, Director of Wildlife Programs
The U.S. Fish and Wildlife Service recently announced it is investigating whether to add moose in Michigan, Minnesota, Wisconsin and North Dakota to the federal endangered species list. The agency will consider whether the moose in question represent a Midwestern subspecies that is in decline. A 60-day period for public comment will end August 2.
Michigan’s moose population is not what biologists expected when a major effort was launched to restore the species 30 years ago. A population goal of 1,000 animals by the year 2000 was set by the DNR, but was never reached. For this year, the DNR’s official estimates are 323 in the western Upper Peninsula that resulted from transplanting Ontario moose in 1985 and 1987, and about 100 in the eastern U.P.
There is also a currently thriving moose herd on Isle Royale. The estimates for the mainland of Michigan are based on spotting moose from fixed-winged aircraft and applying a “correction factor.” There is no statistically reliable difference in estimates from surveys in 2006, 2007, 2009, 2011, and 2013 for the western U.P. Biologists did observe a decline in the proportion of calves in the population and think that a population decline may have occurred. The recommendation of the state’s Moose Hunting Advisory Council is to allow hunting of moose only if the population maintains a growth rate of three percent or more per year. So, at present moose are not hunted anywhere in Michigan.
In pre-settlement times, moose inhabited all of Michigan except for the southwestern part of the Lower Peninsula. However, moose were probably never abundant in the L.P. By the 1880s moose were gone from the Lower Peninsula and scarce in the U.P. The DNR contends moose may have completely died out from the U.P. and then reestablished through immigration from Ontario. A mid1930s transplant of 63 moose from Isle Royale to various places in the Upper Peninsula was judged as a failure.
The case for a Midwestern subspecies of moose is based on skull characteristics and it’s going to be tough to determine whether Michigan actually has a different moose than say, Ontario. Taxonomic or genetic data will presumably be considered by FWS in its review along with the somewhat questionable history of moose in the U.P.
If Michigan’s moose are considered threatened or endangered under federal law, the real debate will be over what options for “recovery” are reasonable.
Moose populations are affected by numerous factors including some that people will be unable or unwilling to address. In Michigan, two important pieces of the moose puzzle are deer and wolves. The Isle Royale moose population is presently thriving precisely because the island has no deer and no wolves. Deer carry a brain worm that is devastating to moose (and elk) but that doesn’t impact the deer. Moose can thrive with deer only in regions where they don’t occupy the same habitats. In Minnesota, researchers have documented that at least 20 percent of moose die from brain worm and many more are likely made vulnerable to wolves because of the disease. If maintaining moose depends on reducing deer numbers, sound moose management will be a hard sell to the Michigan public. There might be more support for reducing wolf numbers, but that might mean more deer and more brain worm. And there is evidence that the thriving moose population of Isle Royale—without wolves to keep the numbers in check—will fairly soon destroy the balsam fir and other key habitat components on which moose depend.
Some ecologists also think moose management in states like Michigan that are on the southern fringe of the species’ North American range is also being complicated by climate change. One important way that could work is by driving up populations of winter ticks. The tiny parasites can literally suck the life out of moose; researchers in New Hampshire have found more than 100,000 ticks on a single moose. A few mild winters can cause tick populations to soar.
In the face of such challenges, moose management in Michigan will likely remain very difficult. The FWS’s endangered species listing process is sure to bring related issues to the forefront over the next year or two.