Red foxes could help in Lyme disease battle


To the Editor:

While not exactly lions, tigers and bears, the recent sightings of an Eastern coyote, stealthily at large in Edgartown, and red foxes, openly frolicking in Woods Hole, have been the cause of much discussion and speculation among the human populace here on Martha’s Vineyard.

One question being posed: Could either of these animals be of any practical use to us in terms of our Lyme disease–carrying white-footed mouse situation?

It is true that coyotes will prey on rodents, but they do not cause Lyme disease rates to drop. In fact, nationwide, invasive coyotes are causing Lyme disease rates to soar.

That’s because these invasive coyotes (said to be part wolf) are much larger than red foxes, and tend to drive resident red foxes out when encountering them — and red foxes do cause Lyme disease rates to drop. Drastically. (Proceedings of the National Academy of Sciences: “Deer, Predators and the Emergence of Lyme Disease”; Proceedings of the Royal Society B: “Cascading Effects of Predator Activity on Tick-Borne Disease Risk”.)

Unlike Woods Hole, however, we have no red foxes on the Vineyard, having killed them off at some point in the not too distant past. What we can lay claim to though, is a Lyme disease rate five times higher than Woods Hole’s — a scenario which, unfortunately, makes perfect sense. The science is clear: Lyme disease rates skyrocket in the absence of red foxes.

People are rightly concerned about the introduction or reintroduction into the wild of animals of any sort on the Island … but, if we were to utilize a limited number of sterile, radio-monitored red foxes, we could conceivably take advantage of their remarkable Lyme disease–quelling capabilities in a controlled way. Emphasis on control. The genie, in other words, could be put back into the bottle.

Naturally, precautions would have to be taken to ensure the protection of special-status species, poultry, and other animals by, for example, deploying red foxes in some areas only in the off-season — or not at all.

There are, of course, other small-mammal critical host tick-borne diseases lurking in our environment, and any Vineyard-based pilot program looking at the potential effects of red foxes against Lyme disease would do well to also consider impacts on ehrlichiosis, tularemia (rabbit fever), babesiosis (Nantucket fever), and the rest.

Speaking of Nantucket, it shares, along with Martha’s Vineyard, the dubious distinction of having the highest Lyme disease rates in Massachusetts. And, you guessed it, as it just so happens, the Vineyard and Nantucket are also the only places in the entire commonwealth without any red foxes.

Thomas Sullivan
Vineyard Haven