John Chenger wrote:Keep in mind not only might it take years for a "human assisted" WNS to start growing on bats at a site, then on top of that it may be a couple of years before anyone actually notices WNS at a site, due to lack of visitation, lack of bat surveys, lack of many bats at a site to begin with, lack of people visiting the site when bats would be there anyway, and probably a couple of other factors. A few posts back someone mentioned the gated sites or mine sites prove WNS is only moving bat-to-bat and people have no influence. This is flat wrong, as a case can rather easily built that at each PA and WV site to allow for "human assisted" influences.
As a case in logic, though, and assuming that WNS is all of one variety of fungus, it would be logically impossible to prove that WNS is distributed by humans, unless all bats were banded, and all banded bat movement were tracked, and no non-banded bats were found at site which became infected; concurrently with all human movement into/out of the cave being tracked, along with logs of caves which those humans had visited for X years into the past, the decontam records of those cavers and records of WNS in those caves.
That's a lot of variables to record in order to definitively prove that humans personally spread WNS. "Building a case" without them would only indicate level of possibility, not certainty. I'm personally skeptical that cavers are a major vector, given that caving has been somewhat popular in the Northeast for at least 60 years, WNS is first going critical mass now, people or their gear show no evidence of being personally affected, and most cavers don't touch or physically disturb the bats or the bats' nearby surroundings.
Now this is not to say that some human environmental alteration isn't responsible...I just don't subscribe to the "cavers cause it syndrome." Cavers, of all people, should recognize the vector of many fungal infections (think histoplasmosis) is such that it preys on the stressed and immune-compromised at a much higher rate than the healthy and hale. If the bats are stressed and immune compromised they likely fall victim to WNS at a much greater rate than usual. Such is proving the case with colony collapse syndrome-- bees which are under stress are falling victim at higher rates than healthy unstressed hives.