2020/06/15 by D. Ellingwood, Peter J. Pekins, Henry Jones +1 · 1 citation
Immunology and Microbiology · Biochemistry, Genetics and Molecular Biology · Medicine · #Vector-borne infectious diseases #Insect and Arachnid Ecology and Behavior #Viral Infections and Vectors
paper · pdf · doi:10.2981/wlb.00619
openalex publication_date 2020/06/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Many wildlife populations are experiencing a variety of environmental pressures due to the direct and indirect consequences of a changing climate. In the northeast, USA, moose Alces alces are declining in large part because of the increasing parasitism by winter tick Dermacentor albipictus, facilitated by high host density and optimal environmental conditions. To test this hypothesis, and better understand the influence of this interaction on the stability of the regional population, we constructed a population viability model using data collected through comprehensive survival and productivity studies in 2002–2005 and 2014–2018 in northern New Hampshire. Years of heavy tick infestation (epizootics) saw a marked reduction in calf survival (< 50%), adult calving (< 60%), twinning rate (< 5%) and complete loss of yearling productivity. We conducted population viability analysis using VORTEX ver. 10.2 to model this moose population for 40 years using mean demographics from both time periods, including environmental variation measured in the field during winter tick epizootic (2002, 2014, 2015, 2016) and non-epizootic (2003, 2004, 2005, 2017) years. This exercise highlights the influence of winter tick infestation on the trajectory of the population with the potential for rapid population growth or decline depending on the frequency of epizootics. We suggest a shift in moose management strategy focused on lowering moose density, assuming continued influence of climate change on the host–parasite relationship.