The Imminent Extinction of East America's Most Common Bat

[Lagmonster]

Source Articles: Wired and NERS Blog

Both articles are discussing a deadly disease which is hitting the common brown bat population hard. Naturally, these animals are important in the curbing of insect populations, and their loss has reasonably significant environmental and economic impacts.

In the worst case, Ed Yong's source at Boston University estimates a 99% chance of extinction on the East Coast within 16 years.

This is an excellent example with which to identify how a population, totally unprepared for the introduction of new diseases, can be wiped out almost literally overnight. And while I'm not prepared to say that it's our fault for crowding them together and constantly importing new germs from all over the world, humanity certainly does seem to be an indirect culprit or, at least, a suspect in the case.

[Broomstick]

How are we "crowding them together"? The Common Brown Bat naturally congregates in massive colonies, or did you miss the part about "caves occupied since the ice ages"? We don't crowd them, they crowd themselves.

We might, however, be in part responsible for importing new pathogens, perhaps unintentionally. See the recent West Nile Virus die-off among the corvids in the US, along with other birds.

There are, of course, other bat species, some affected by the same disease, some not so much. Something like the Indiana Bat is rarely affected by white nose disease but then they roost in very small groups, perhaps a dozen at most. Unfortunately, the Indiana Bat is also endangered due to loss of roosting space (they use smaller spaces, but need more of them) and possibly other pressures in the environment.

It is possible the WNS is a completely natural phenomena and humans have no role in it - new diseases do spring up on their own from time to time. More likely, it's a new, naturally occuring disease that humans might occasionally help spread because we're nosy fuckers who sometimes investigate caves and we move around a lot, which may spread fungal spores. But given the massive colonies the CBB roosts in it's entirely possible this is a bat-spread disease.

Bottom line: we don't know where this came from, we don't know how it spreads from colony to colony, and we don't know how to stop it.

[General Zod]

How are we "crowding them together"? The Common Brown Bat naturally congregates in massive colonies, or did you miss the part about "caves occupied since the ice ages"? We don't crowd them, they crowd themselves.

We might, however, be in part responsible for importing new pathogens, perhaps unintentionally. See the recent West Nile Virus die-off among the corvids in the US, along with other birds.

There are, of course, other bat species, some affected by the same disease, some not so much. Something like the Indiana Bat is rarely affected by white nose disease but then they roost in very small groups, perhaps a dozen at most. Unfortunately, the Indiana Bat is also endangered due to loss of roosting space (they use smaller spaces, but need more of them) and possibly other pressures in the environment.

It is possible the WNS is a completely natural phenomena and humans have no role in it - new diseases do spring up on their own from time to time. More likely, it's a new, naturally occuring disease that humans might occasionally help spread because we're nosy fuckers who sometimes investigate caves and we move around a lot, which may spread fungal spores. But given the massive colonies the CBB roosts in it's entirely possible this is a bat-spread disease.

Bottom line: we don't know where this came from, we don't know how it spreads from colony to colony, and we don't know how to stop it.

Researchers in one of the articles suggested it was likely imported and the bats were unprepared for its impact. Considering it was first documented in New York which is a massive travel destination it seems fairly plausible.

[Ziggy Stardust]

Bottom line: we don't know where this came from, we don't know how it spreads from colony to colony, and we don't know how to stop it.

Although it is true that we know very little about it, the evidence seems to point to it being at least correlated with human activity. The type of fungus infecting the bats is most closely related to species found naturally only in Arctic permafrost. However, it also occurs in human dwellings (especially children's sandboxes, apparently). Most likely, one of the several migratory species of bat, which tend to roost in attics and barns, contracted the fungus, and helped spread it to populations roosting in caves.

On another note, the actual impact of it may be overblown. It is certainly a serious problem, but a lot of "chiroptologists" (not a real term for bat scientists, but I like to use it anyway) are not worried about true extinction. Myotis are very resilient and widely distributed bats, and it is incredibly difficult to do a census on a population. The studies being done on the effect of the fungus only focus on populations roosting in caves, which are probably not even a majority of little brown bat. The bottom line is, more comprehensive research needs to be done.

[Wing Commander MAD]

Not terribly surprising, they've been getting their assed absolutely kicked by this in the last few years, admittedly I didn't realize it was so bad as to potentialy cuase extinction in only a few decades. Mind you I'm in PA, so I'm more likely to have heard about this sooner than most of you.

[LadyTevar]

It's already spread to a cave in West Virginia, iirc.