Thirteen pine martens (Martes Americana) were sampled periodically from July 1979 to September 1980 for plague (Yersinia pestis) antibodies and their fleas collected and identified. Four individuals were positive for plague antibodies on 8 of 24 sampling occasions. Titer peaks in these individuals occurred simultaneously in early winter but fell to undetectable levels by late spring. A chipmunk flea (Monopsyllus ciliatus) was the most common ectoparasite constituting 55% of all individuals collected. Thirty-one percent of all fleas belonged to Chaetopsylla floridensis, a species previously unreported in California. The remains of ground-dwelling sciurids (chipmunks, Eutamias spp., and ground squirrels, Spermophilus spp.) were very common in marten scats during the period preceding elevated titers. For this reason, and the fact that 92% of all fleas collected from martens during this same period were found more commonly on chipmunks and ground squirrels, these rodents were implicated as the source of the martens' exposure to plague.
Zielinski, W. J.
"Plague in pine martens and the fleas associated with its occurrence,"
Great Basin Naturalist: Vol. 44
, Article 21.
Available at: https://scholarsarchive.byu.edu/gbn/vol44/iss1/21