The ecology of tick-transmitted infections in the redwood chipmunk (Tamias ochrogenys)

Janet E. Foley, Nathan C Nieto

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

The redwood chipmunk contributes to the maintenance of tick-borne diseases in northern California. The range of redwood chipmunks overlaps that of western black-legged ticks and tick-borne disease, including granulocytic anaplasmosis and Lyme borreliosis. Chipmunks have high Anaplasma phagocytophilum PCR- and seroprevalence, are infested with a diversity of Ixodes spp. ticks, and are reservoir competent for Borrelia burgdorferi. We hypothesized that chipmunks could maintain tick-borne disease on the forest floor while also potentially bridging infection to arboreal sciurids as well. We used radio-telemetry to evaluate chipmunk movement and use of trees, characterized burrows, described prevalence of tick-borne disease, and identified ticks on these chipmunks. A total of 192 chipmunks from Hendy Woods, Mendocino County, California, USA, was evaluated between November 2005 and April 2009. The mean density was 2.26-5.8chipmunks/ha. The longest detected life span was 3 years. Female weights ranged from 80 to 120g and males from 80 to 180g. The A. phagocytophilum and Borrelia spp. seroprevalence was 21.4% and 24.7%, respectively, and PCR prevalence for these pathogens was 10.6% and 0%, respectively. Ixodes spp. ticks included I. angustus, I. ochotonae, I. pacificus, and I. spinipalpis. The mean infestation level was 0.92 ticks/chipmunk. Based on telemetry of 11 chipmunks, the greatest distance traveled ranged from 0.14 to 0.63km for females and 0.1-1.26km for males. Areas occupied by chipmunks ranged from 0.005 to 0.24km 2 for females and 0.006-0.73km 2 for males. On 3 occasions, chipmunks were found in trees. Burrows were identified under a moss-covered redwood log, deep under a live redwood tree, under a Douglas fir log, in a clump of huckleberry, in a root collection from an overturned Douglas fir tree, and in a cluster of exposed huckleberry roots. The biology of the redwood chipmunk has multiple features that allow it to be an important reservoir host for tick-borne disease in northwestern California.

Original languageEnglish (US)
Pages (from-to)88-93
Number of pages6
JournalTicks and Tick-borne Diseases
Volume2
Issue number2
DOIs
StatePublished - Jun 2011
Externally publishedYes

Fingerprint

Sequoia
Sequoia sempervirens
Tamias
Sciuridae
Ticks
Ecology
ticks
ecology
Tick-Borne Diseases
tick-borne diseases
Infection
infection
Huckleberry Plant
Ixodes
Gaylussacia
Pseudotsuga
Ixodes pacificus
Anaplasma phagocytophilum
Telemetry
Seroepidemiologic Studies

Keywords

  • Anaplasma phagocytophilum
  • Borrelia burgdorferi sensu lato
  • Borrelia spp.
  • Relapsing fever
  • Reservoir
  • Rodent

ASJC Scopus subject areas

  • Infectious Diseases
  • Insect Science
  • Parasitology
  • Microbiology

Cite this

The ecology of tick-transmitted infections in the redwood chipmunk (Tamias ochrogenys). / Foley, Janet E.; Nieto, Nathan C.

In: Ticks and Tick-borne Diseases, Vol. 2, No. 2, 06.2011, p. 88-93.

Research output: Contribution to journalArticle

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