Date of Award
Summer 8-22-2025
Level of Access Assigned by Author
Open-Access Thesis
Degree Name
Doctor of Philosophy (PhD)
Department
Ecology and Environmental Sciences
First Committee Advisor
Pauline Kamath
Second Committee Member
Sandra De Urioste-Stone
Third Committee Member
Kristina Cammen
Additional Committee Members
Laura Rickard
Richard Gerhold
Abstract
Moose (Alces alces) are an ecologically, economically, and culturally important species to communities within Maine. To many, moose is synonymous with Maine and part of the cultural heritage of the region; for example, members of the Wabanaki Tribal Nations rely on moose meat for sustenance hunting and rites of passage ceremonies, and rural communities rely on revenue brought in through moose hunting and tourism. However, over recent years moose populations in the northeastern United States have been threatened due to parasitic infections, mostly from the winter tick (Dermacentor albipictus) but little is known about the distribution and effects of co-infecting parasites. Due to the multifaceted importance of moose in Maine we use a One Health approach to evaluate biological and social implications of parasitic infections. We engaged moose hunters in active scientific research through opportunistic sample collection to 1) determine the geographic distribution and 2) identify risk factors associated with four parasites (Anaplasma sp., Toxoplasma gondii, Parelaphostrongylus tenuis, and Babesia odocoilei) in Maine moose; we documented a wide geographic distribution of all four parasites in the moose population and found that geographic location and age influenced the risk of parasitic infection. Through a combination of methods such as live capturing moose calves, laboratory identification of parasitic infection, and hematological analysis we also 3) evaluated the role co-infection, between winter ticks and Anaplasma sp., has on overwintering moose calf survival, and 4) assessed the impact of Anaplasma infection on hematological parameters (packed cell volume, total protein, and white blood cell counts); and found that co-infection with moderate and heavy winter tick infestations and Anaplasma infection significantly reduces moose calf survival, and infection was associated with both a significant reduction in packed cell volume (indicative of anemia) and an increase in total serum protein. Given that parasitic infections are impacting the moose population, we further 5) explored whether host genetics affects the probability of surviving winter tick infestations using a restriction-site associated DNA sequencing (RAD-seq) approach that generated host genomic data from animals that survived heavy winter tick infestations, and those that did not. Through this study, we found animals that did not survive heavy winter tick infestations had higher genetic diversity (observed and expected heterozygosity, and nucleotide diversity) compared to survivors; we also identified a locus potentially under selection that mapped to the ITGB3BP gene, encoding a binding protein that is thought to repress the NF-kB pathway, which regulates inflammation as well as other innate and adaptive immune responses. Finally, due to the importance of moose culturally and the multitude of parasitic threats impacting their populations, we performed a quantitative content analysis to 6) describe the content of Maine’s newspaper media coverage related to the moose – winter tick system. Our results show messaging surrounding the moose – winter tick system changed over time and reflected well publicized management and research actions but continuously presented messages of trust in experts and managing officials. Through this work we employed an interdisciplinary approach to parasitic infections in an iconic species. These results can help wildlife managers in the northeastern United States better understand and manage moose, as they face continued pressure from parasites to the population. Further, these results provide an example of the One Health approach being applied to a non-zoonotic disease system, broadening the One Health framework to include impacts to species of cultural importance.
Recommended Citation
Woods, Alaina, "Biological and Social Implications of Parasitic Infections in the Maine Moose Population: A One Health Approach" (2025). Electronic Theses and Dissertations. 4236.
https://digitalcommons.library.umaine.edu/etd/4236