Incompetent Reservoirs: A Best Bet Against Lyme?
The western fence lizard may buffer against Lyme Disease.
Lizards are, therefore, low in ‘reservoir competence,’ a measure of efficient ability of an animal to infect an uninfected tick.
What’s that mean?
Habitats or regions that have higher densities of lizards may ultimately have lower numbers of infected ticks and that indirectly means lower human risks.
Other hosts take on the opposite role: reservoir ‘competent’ hosts like mice, voles, or shrews have an incredible ability to re-infect ticks, and the bacterium does little to mouse mortality.
So, habitats that have greater numbers of species will likely decrease the overall competence of animal reservoirs, and lower numbers of infected vectors means decreased human risks.
Rick Ostfeld and Felicia Keesing have worked on this hypothesis that biodiversity buffers disease. Though it’s a debated hypothesis (some consider it only local phenomenon not generalizable to other disease systems), this lizard work definitely supports Ostfeld and Keesing’s ideas.