Ear Tagging Increases Tick (Ixodes dammini) Infestation Rates of White-Footed Mice (Peromyscus leucopus)

Abstract

The white-footed mouse (Peromyscus leucopus) is an important host of the deer tick (Ixodes dammini), and the principle reservoir for the spirochete (Borrelia burgdorferi) known to cause Lyme disease. In summer and autumn 1991, we uniquely marked small rodents, including P. leucopus, with metal ear tags. The presence of ear tags increased rates of infestation by larval ticks on mice by 50 to 100%, probably because the tags reduced grooming efficiency. Because larval deer ticks acquire the Lyme disease spirochete more efficiently from P. leucopus than from other mammalian and avian hosts, increasing the numbers of ticks parasitizing mice may cause a higher percentage of ticks to carry Lyme disease.