Moose and Winter Tick Populations in Northern Maine

Impacts of climate change are going to be seen heavily in the Northeast (IPCC, 2022; USGCRP, 2021; Fernandez, 2020). The Northeast is warming faster than any other region in the United States with a projection of 5.4 °F (3 °C) when the rest of the world reaches 3.6 °F (2 °C) (Fernandez, 2020).  New England is a place of industry and commerce, historically along rivers, canals, coasts and other bodies of waters, including areas that are already at risk (USGCRP, 2021; Fernandez, 2020). An increase of temperature is causing warmer, later winter and earlier spring temperatures in the Northeast which is impacting the moose population and tick abundance (IPCC, 2022; USGCRP, 2021; Yates, 2021; Jones, 2019). In 2013 moose hunting in Maine contributed $20,800,00 to the economy (DiMatteo, 2019).

Main threats to this region: 

- Shorter winters 

- Extreme weather events 

- Increase of insect activity and abundance 

- Increase flood frequency and severity 

Maine's moose has driven a huge part of the economy. With a shorter winter and increase of moose mortality, the economy and culture are being impacted. Outdoor industries (agriculture, fishing, etc) generate $100 billion annually, which supports half a million jobs region-wide (USGCRP, 2021).

Tourism is also being impacted with the average length of winter recreation season and total visits are projected to decrease by mid-century with a lower scenario (RCP4.5) (USGCRP, 2021). 

The Wabanaki tribe in Northern Maine’s culture and traditions could be destroyed due to their heavy reliance on moose with their hair, meat, skin and hides (DiMatteo, 2019). Moose have great cultural and economic significance in the state of Maine.

Shorter Milder Winters 

An increase of temperature is leading to an increase of parasites and vectors, specifically winter tick in Maine (Weiskopf, 2019). In the northeastern United States, winter ticks play a substantial role in the population dynamics of moose causing high mortality rates of 10 to 11-month-old calves and reduced productivity in yearling and adult cows (Jones, 2019). Warmer temperatures in the winter and less snow coverage can lead to increased survival of tick larvae and egg production (Weiskopf, 2019). Earlier frosts and snowfalls decrease the amount of time tick larvae are exposed to moose (Weiskopf, 2019).

Warming Climate 

Moose become more stressed with warming climate (Weiskopf, 2019). Higher summer temperatures could increase moose heat stress because they will struggle to regulate their body temperature (Rempel 2011). Increased temperatures are also impacting moose food supply (Maine Dept., 2021; DiMatteo, 2019; Jones, 2019). Moose are selective when choosing a habitat and a good habitat (Northern Maine) means a densely populated area of moose (Maine Dept., 2021). Population density can throw things off in disease, parasites and population balance as a whole (Yates, 2021). 

Parasitic Disease Increase

Above upper critical temperatures, moose become heat stressed and increase their metabolism, heart rate, respiration rate, reduce food intake, and lose body weight which leads to malnutrition and immunosuppression (Weiskopf, 2019). These nutritional deficiencies in summer are impacting moose and their ability to reproduce (Yates, 2021; Weiskopf, 2019). Infestation of winter ticks causes premature loss of winter hair because the moose are grooming more to remove the ticks (Yates, 2021; Weiskopf, 2019; Jones, 2019). Hair loss can contribute to increased metabolic demands including hypothermia, anemia and the attachment of parasites (Yates, 2021; DiMatteo, 2019; Weiskopf, 2019).

Moose have a vast cultural and historical significance in Maine which impacts indigenous tribes, tourism, food security, hunting, arts (Fernandez, 2020; DiMatteo, 2019). Maine's economy is experiencing the impacts of climate change. Tourism is also being negatively impacted by the depletion of the moose population. Moose drive a multimillion dollar tourism industry in the state of Maine in hopes to see the amazing creature (Rempel, 2011). Tourists will either see no moose or see one that’s patchy, full of ticks, and looks starved (Rempel, 2011). The depletion of the moose population is having an extreme toll on many communities, not just the moose. 

Other impacts include: 

- Loss of culture

- Increased storm surge 

- Loss of food and economic source

- Loss of local knowledge 

Reducing Moose Density 

One key strategy for adapting to the winter tick problem on moose in Northern Maine is reducing the moose density which then would lessen the tick abundance (Kamath, 2021). Reducing moose density decreases the number of available hosts which decreases the number of winter ticks on the landscape (Fortin, 2022). One option for creating a less dense environment in Northern Maine would be moving moose and disrupting the winter tick population and increasing the overall calf survival rate (Kamath, 2021). This increases the health and wellbeing of moose of their ability to reproduce (MDIFW, 2021). Maine Department of Inland Fisheries and Wildlife's plan to manage moose is to have healthier moose where reproduction is higher and parasites (winter tick) are lower (MDIFW, 2021). Less ticks mean newborn calves are healthier and have an increased survival rate (MDIFW, 2021). Additionally, there are increased reproductive rates and breeding occurs at an earlier rate which allows for higher twinning rates (MDIFW, 2021). 

Phoebe Boardman graduated in 2024 and was an Environmental Studies major and Education minor during her time at St. Lawrence University in Canton, New York. She is from the coast of Maine and was interested in how the future of her state was impacted by climate change directly. She is passionate about the outdoors and care for wildlife. Phoebe created this webpage for Dr. Rosales' Adaptation to Climate Change course in the Spring of 2022.