Bats’ Demise: Climate Caused?

There is speculation (of course, and in the absence of a smoking gun bacterium or virus) that behavioral changes due to warmer winters is to blame for the so-called White Nose Syndrome in bats. The fungus is only taking advantage of bats so weak they can’t wipe their noses. Here’s one wildlife pathologist voicing the global warming explanation:

Stone said the bats are dying from starvation and weakened immune systems resulting from the unusually warm late fall and winters during the last several years, which has kept bats flying even when fewer insects are available to eat.

That has led bats to begin hibernation with insufficient fat reserves, prompting them to starve and sometimes leave the safety of caves in search of food during cold weather, which is usually fatal.

“The good news is, this is not going to wipe out all the bats. All the bats are not in tough shape, a number of them have enough fat,” said Stone. “There are a lot of bats that have died that don’t have any fungus.”

Does the theory hold water? Maybe. It seems possible that white-nosed northern state bats (NY, VT and MA) might be less well adapted to stay in winter hibernation when temps are still warm while southern state bats have long done so.

Also with average winter temperatures a few degrees warmer hundreds of miles south there are probably still at times enough cold-blooded insects on the wing for bat food. On a warm December day, the Asian Ladybird Beetle swarms alone could feed a legion of bats where we live in Southwestern Virginia and the cost of leaving the roost would well be compensated for by a good meal. Not so with warm winter spells to the north.

But early on, a strong correlation was noted between caves where WNS was found and those visited frequently by cavers. Here again, perhaps the added stress of hibernation disruption compounded the metabolic stress the bats were under.

My guess is that we’ll have a handle on WNS long before we understand CCD in bees. Stay tuned.

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fred
fred

Fred First holds masters degrees in Vertebrate Zoology and physical therapy, and has been a biology teacher and physical therapist by profession. He moved to southwest Virginia in 1975 and to Floyd County in 1997. He maintains a daily photo-blog, broadcasts essays on the Roanoke NPR station, and contributes regular columns for the Floyd Press and Roanoke's Star Sentinel. His two non-fiction books, Slow Road Home and his recent What We Hold in Our Hands, celebrate the riches that we possess in our families and communities, our natural bounty, social capital and Appalachian cultures old and new. He has served on the Jacksonville Center Board of Directors and is newly active in the Sustain Floyd organization. He lives in northeastern Floyd County on the headwaters of the Roanoke River.

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  1. Not climate but spelunkers and cavers spreading the fungal disease from cave to cave – Completely selfish twits.

    This is similar to the die off reported in tropical frog species over several continets after they were caerlessly infected by scientists and grad students. They did this by reusing uncleaned equipment, clothing and handling the frogs to take measurements (etc).