Do Birds Carry Ticks? What Mice and Chipmunks Reveal
Birds can carry ticks.
Mice can spread infection.
Chipmunks may play a bigger role than expected.
Birds, mice, and chipmunks can all carry ticks—but they play different roles in spreading Lyme disease.
Do Birds Carry Ticks?
Yes, birds can carry ticks.
In one study, ticks were found on approximately 29% of captured birds.
Birds were not found to be infected in this study, but they carried ticks and may help spread them to new areas.
This makes birds important in the geographic spread of ticks, even if they are not the primary source of infection.
Do Mice Carry Ticks?
Yes, mice are one of the most important hosts for ticks.
Researchers found that approximately 70% of mice were infested with at least one tick.
More importantly, about one-third of mice were infected with Borrelia burgdorferi, the bacteria that causes Lyme disease.
This makes mice a key reservoir for Lyme infection.
Do Chipmunks Carry Ticks?
Yes—and in this study, chipmunks had even higher infection rates.
Over 90% of chipmunks were infested with ticks.
More than 80% tested positive for Borrelia burgdorferi.
This suggests chipmunks may play a larger role in Lyme transmission than often assumed.
What About Other Animals?
Researchers also evaluated shrews and voles.
- Some shrews carried ticks, but infection rates were lower
- No ticks were found on the single vole captured in this study
Not all small mammals contribute equally to Lyme disease risk.
What the Study Found
In their study of tick-borne pathogen transmission in southeastern Canada, Dumas and colleagues examined how birds and rodents contribute to Lyme disease spread.
They collected over 25,000 larval ticks, along with nymphs and adult ticks, and sampled multiple host species in an endemic region.
The results showed that small mammals—especially mice and chipmunks—play a central role in maintaining Lyme disease in the environment.
Ticks were most commonly attached to the ears of small mammals.
Birds, while less likely to be infected in this study, help distribute ticks across regions.
Why This Matters for Lyme Disease Risk
Lyme disease risk depends on both tick presence and infected hosts.
Small mammals help maintain infection locally.
Birds help expand the geographic range of ticks.
This combination contributes to the spread of Lyme disease into new areas.
Clinical Takeaway
Birds, mice, and chipmunks all play a role in the life cycle of ticks.
Mice and chipmunks are key reservoirs for Lyme disease, while birds help distribute ticks to new environments.
Understanding these roles helps explain how Lyme disease spreads—and why exposure risk can vary by location.
Related Articles
- What nesting songbirds tell us about Lyme disease in Canada
- Impact of environmental changes on tick-borne diseases
- Why Lyme disease may be under-detected in Canada
References
- Dumas A, Bouchard C, Dibernardo A, et al. Transmission patterns of tick-borne pathogens among birds and rodents in southeastern Canada. PLOS ONE. 2022.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
