Over the past decade, the moose population in Minnesota has been

rapidly declining. Experts believe that if current trends continue, the

Minnesota moose population will be extirpated from Minnesota

altogether by 2050. The Minnesota Department of Natural

Resources’ (MNDNR) aerial moose surveys from 2005-2015, have

established rapid declines in moose population. With 2005 numbers

estimated around 8,160 individuals, and 2015 estimates reaching only

3,450, there has been an astonishing 60% decrease in the Minnesota

moose population in the last decade. Between years 2006 to 2007

alone, Minnesota moose populations experienced a dramatic 23%

decrease, with other one-year periods experiencing alarmingly similar

declines. Moose are slowly disappearing from most of the states

throughout the moose’s southern range, however, Maine’s moose

population is actually on the rise. Addressing this problem and

highlighting possible explanations for why moose populations are

declining are of utmost concern. Climate change seems to be the

overwhelming cause for the decline. Mean summer and winter

temperatures are rising, resulting in numerous problems for the

Minnesota moose population as a whole.

To determine what is being done successfully and what could be done differently to

possibly restore the Minnesota moose population, I have analyzed current state moose

management plans for Minnesota and Maine. Secondly, I analyzed historic Minnesota

temperatures and created graphs depicting the warming trends in March and July over

the past century, as well as created a graph depicting how the number of days above

heat stress in January has increased over the past 55 years. I also conducted an

interview with an Entomologist at Saint John’s University and gained more

information about ticks and how climate change will affect parasitic populations.

Additionally, I conducted a second interview with a moose zoo keeper at the

Minnesota Zoo to find out how their moose are contributing to moose research in

Minnesota. Then I collected data from the MNDNR to create a line graph to show the

moose decline over the past decade. The remaining information for my thesis was

collected from secondary sources from various peer-reviewed articles and books.

Over the past century, climate change has caused mean summer and winter temperatures to

rise, resulting in multiple factors coming together to negatively affect moose populations. Tick,

brain worm, and giant liver fluke populations are increasing with climate change, which is

leading to disease and ultimately death for large numbers of MN moose. In addition to

heightened parasitic populations, climate change will increase the timeframe in which moose

are susceptible to heat stress. My analysis of historic MN temperatures found steady increases

in average temperatures for both March and July and that the number of days a moose is

exposed to heat stress in January has increased. While climate change appears to be the largest

contributor towards the decline in MN, the combination of these factors, along with habitat

loss/fragmentation, predation, and copper deficiency herald a bleak future. More research

needs to be implemented to determine exactly why this decline is occurring, but if climate

change is the driving force behind the decline in MN moose populations, it is likely that little

can be done to prevent the eradication of moose from this state. In the meantime, the MNDNR

needs to continue to modify the current management plan annually in a way that they believe

best benefits the moose population in order to maximize the potential of a resurgence of moose.

Minnesota Moose: An Analysis of Moose Decline in Minnesota

Maggie Gleason

Advisors: Jean Lavigne and Derek Larson

1965 1986 2010

This map represents the shift in moose distribution in MN over a 45-year span. The

dark gray is primary moose range and light gray is secondary moose range.

http://files.dnr.state.mn.us/fish_wildlife/wildlife/moose/management/

Introduction:

Methods

Results:

A moose infested with winter ticks.

http://www.nrri.umn.edu/moose/images/InfTowerCowTicks.JPG

A tick infested moose rubs its hair

follicles off, revealing the white portion of the

follicle, resulting in a “ghost moose.” http://

www.nrri.umn.edu/moose/images/Info/

GhostCalf.JPG

A research biologist and a MN Zoo veterinarian

fitting a sedated cow with a radio collar and

collecting samples to help researchers determine

the cause for the decline.

http://www.startribune.com/sportsoutdoors/15895882.html

Training moose calves at the

MN Zoo to participate in

MNDNR moose research. Data collected from the MNDNR 2015 Aerial Moose Survey

8,160

8,840

6,860

7,890

7,840

5,700

4,900

4,230

2,760

4,350

3,450

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Mo

ose

Est

ima

te

Survey Year

Minnesota Moose Decline 2005-Present

www.dnr.state.mn.us/climate/historical/acis_stn_data_monthly_table.html?sid=mspthr&sname=twin%20cities%

20area&sdate=por&edate=por&element=avgt&span=annual&counts=no; http://www.almanac.com/weather/

history/MN/Grand%20Marais/2015-01-31

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Number of Days with a Mean Temperature Above 23° F in Grand Marais, MN in January

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