The Western fence lizard’s blood contains a protein that kills the bacteria responsible for causing Lyme Disease. Borrelia burgdorferi is the bacteria and pathogen found in the guts of Western black-legged ticks. However, when these ticks bite Western fence lizards and suck their blood, they are cleansed of the bacteria, and therefore can’t spread it to other animals or humans. Furthermore, it is thought western fence lizards are the favorite source of blood for early stage ticks, or young ticks, so once they have been cleared of the bacteria, for the rest of their lives they do not transmit Lyme disease to any other creatures.
Of course, there is still Lyme disease in California, but it has been speculated there is less than on the East Coast due to the presence of western fence lizards and their bacteria-killing ability. Researchers now are trying to figure out if another factor is actually increasing the number of Western black-legged ticks — the die-off of one million trees in California coastal areas due to Sudden Oak Death. The loss of trees has resulted in gaps in forested areas, which may be shifting the landscapes to be both drier and hotter. Land that has been changed in these ways is believed to be more hospitable to ticks, and to Western fence lizards. In forested areas with tree losses from Sudden Oak Death there has been an increase in ticks. So far though, it isn’t clear if the lizard population has also increased, and if the larger number of ticks all contain the Lyme disease causing bacteria.
Separate research recently established a link between species loss and an increase in human diseases. It appears this is a similar situation, where the loss of scores of trees has increased the number of disease-spreading ticks. Sudden Oak Death is believed to have been introduced when ornamental plants were imported from Asia. Will the populations of Western fence lizards sprout up in the same areas where there are more ticks, and clear them of the harmful bacteria? Perhaps some day avoiding walking or hiking in areas known to have substantial tree losses from Sudden Oak Death will become a Lyme disease prevention measure. It is also a possibility the sensible encouragement of Western fence lizards to live in areas with ticks, and educating the public to do no harm to these helpful lizards will be tried in order to reduce, or maintain lower levels of, Lyme disease.
Image Credit: Nehrams2020