Mortality assessment of calf moose (Alces alces) during successive years of winter tick (Dermacentor albipictus) epizootics in New Hampshire and Maine.

• Main Authors: Jones, Henry, Pekins, Peter J, Kantar, Lee, Sidor, Inga, Ellingwood, Daniel, Lichtenwalner, Anne, O'Neal, Matthew
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2018
• Subjects: Alces alces
• Online Access: http://hdl.handle.net/1807/93137; http://www.nrcresearchpress.com/doi/abs/10.1139/cjz-2018-0140

Populations within ecological communities constantly fluctuate due to a multitude of interactions that can be influenced by climate change. Moose (Alces alces Clinton, 1822) populations in northern New Hampshire and western Maine, subunits of the largest regional moose population in the continental United States, are suspected to be declining due to increasing frequency of winter tick (Dermacentor albipictus Packard, 1869) epizootics that cause >50% late winter mortality of 9-12 month-old calves. To investigate this hypothesis, we collected general health measurements of calves captured at 2 study sites in January 2014-2016, and subsequently performed field necropsies and histologic examination of tissues of those radio-marked calves that died during winter/spring. At capture, calves (n = 179) were in normal (66%) and thin (32%) physical condition with high infestations of winter ticks. Most (88%) mortalities (n = 125) were associated with moderate to severe infestations of winter ticks. Gross necropsies and histologic examination found high tick infestations, emaciation, anemia, and endoparasitism; lungworm (species of the genus Dictyocaulus Railliet and Henry, 1907) was also found in most (87%) calves. Three consecutive years (2014-2016) of winter tick epizootics is unprecedented in the region, rare in North America, and arguably reflects a host-parasite relationship strongly influenced by climate change at the southern fringe of moose habitat. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.