Muddawg, My .02 or .05 for you for what its worth.
(Disclaimer - yes I know that many factors play into selling folks on waiting whether we are talking maternity season, or winter, or other reasons why now isn't the best time for bat exclusion. I understand we are in business of solving issues and that we don't always succeed in being able to balance the best for the wildlife with the homeowner, but as an industry I'd like to think we try to make sure folks get the best solution that is also balanced with the wildlife populations we work with.)
Related to this statement - "I know they wont fly until it gets warmer. If I exclude them now, I know that it will be March before I can safely take my excluders down and screen off the holes."
I can't see why this would be a good time of year to start the exclusion because as you stated with only some bats emerging and only on warm up spells you won't be sure they bats are gone till spring, thus the roofer will not begin work.
So if we stop here with this logic, I would convince the folks that the exclusion won't really begin or start till bats become fully active and emerge for spring.
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"I did speak to the realtor this morning and told her that I wouldn't even consider it without at least putting up a bat house in the back yard. But, will that be sufficient to insure that any bat that comes out before spring doesn't freeze to death in the top of a tree? Will that be enough to cover me from the wrath of the Federal Fish and Game department?"
This one is simple bat houses (any on the market commercially) do not hold the same thermal properties as a house does, therefore putting up the bat box while a great conservation tool in the long run, will not result in what so many call us believing it will do. People want to believe they can put up a bat house and it will magically draw bats to it, that they will seek it out because it is a "bat house."
This is far from true, even during the normal active season from spring to fall. Bat houses can be hard to get to establish a colony and this all revolves around a myriad of factors.
So I'd say the answer to this is that it will not solve any of the issues surrounding attempting bat exclusion in winter time. The bats are more likely to try to find a secondary roost which is another home or large structure in the area, or they will freeze when they can't re-enter the home they are one way doored out of during these harsh conditions.
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I can't say 100% they will die, nor can I say they will 100% live, but those who have done this any length of time tend to agree that winter is not bat exclusion season, though people do offer it, most do not.
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"What would y'all do? Anybody else getting bat calls in cold weather?"
I would be trying to convince them the best option is to wait until spring, if I had to I'd be meeting with the roofer to visit about his concerns and where he is working and where the bats are and explaining the myth versus facts. I've had numerous conversations with contractors with similar concerns and 99.9% of them listened and adjusted fire based on our recommendations.
Won't always happen but worth a try to convince them to wait till the better time of year this spring.
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Wink, That sounds like a great program!
Lol!
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P.S. Something for all to remember or to know is that winter bat exclusion is something on the table in most states dealing with WNS (white-nose syndrome) as a potential issue within our industry that needs attention. The more we do to show that we are paying attention to the biological aspects of bat populations and trying to promote exclusions during the spring and fall when most appropriate for conservation, the more we will be listened to on other aspects related to bat exclusion and future regulations coming down the line.
Again, I get it, folks need to eat, money is being paid, not everyone can be convinced to wait, however this doesn't mean you have to take the job.
I live and die by my own ethics and whether others adopt them or not is nothing I can control, but my paycheck is one I know I do my best to be sure aligns with logical decisions that combine the homeowner or clients needs with the wildlife biology and conservation need.
Justin