Fall Cut-off for Bats?

There is plenty of discussion of the maternal black-out period, seems like there was a good discussion of a winter blackout period for bat work. I can't seem to find it in the archives. I know there are issues of changing air patterns and causing potential hibernators to shift in the structure, (possibly to living spaces). If you put new screen on a gable you are not affecting that, so when would you quit putting up excluders?

I guess to put it different, let's suppose that you put up a valve, and it's in the high 30's at night,50's by day and it hit's 80 a few days and gets up into the 50's and 60's at night and bats go out on an evening that starts out in the 50's with some hatch flying around, and drops to 30's by morning because of a cold front. Wouldn't those bats be toast? Would a bathouse next to their entrance provide a minute amount of hope for them? Can they even overwinter in a bathouse? (Big Browns, I'm assuming yes because they can overwinter in my barn?)

I'm thinking you need to look for maybe 5 to 7 days of 50+ lows at night in a forecast to make a window? Or wait till April? Or just do it and provide a bathouse? Or maybe just do it when the customer is shaking up the can of Raid and is not sounding educate-able?

we do seal up work until the temps arent consistent enough for the sealant to properly cure.
Last day of work is tomorrow, then fur trapping

That is an interesting topic that I think needs to be researched. Fortunately in my area we rarely have more than a few days duration of sub freezing temperatures at any given time so bat work for us pretty much can be done year round.

I do bat work year round... I leave the check valves up till spring ... allowing any bat to leave at that time

We have already had a bunch of cold days but still have insects in the air ... Our cold days started in mid October and now we are into a warm spell ... I pulled down 2 different jobs yesterday ... and have no hesitation in doing so

I suspect after this next cold spell coming in ... I will end up leaving them in for the winter ... we will see

You have to remember ... here in Western New York .. there are times bats wont leave till late April ... they start to lie dorment in October ... they will never make it the winter ... they have to leave to either migrate or feed

Curious why would bats leave in April? After going through the winter, is that what you are saying, or did I miss something? I grew up in Western NY, any bat making it through that winter by staying local better be hibernating, lol!

Migrate, Hibernate or Die is more accurate imho.

Justin

Edit - I'm assuming what you mean after re-reading it a few times is that they may be inside a dwelling for the winter and not come out or emerge from hibernation within that structure till April?

Seems like unless it is an open attic, there isn't much way to know they are in there, which is why this topic poses serious implications for all of us and for managing exclusions properly to not seal in any present occupants.

sure there is ... I have been in plenty of attics duriing the winter where they are hanging on the sunny side of the cieling (roof)

People will often complain about hearing somthing during the winter ... then in a few days a bat appears ...or they have somthing in the wall... yet never had a mouse in the house ... generally it is a wintering bat

I have chased the litttle buggers across the joists while they try to hide in the insulation

I do alot of winter bat work

I am sorry I did not answer the question about April .... generally in April ..late april we start to get warm days and as the snow melts the bugs start to come out ... this is when the bats leave the homes ... especially in the city.. they dont hunt all niight unless there are enough bugs to survive on ... where they dont burn more energy then they take in

The most amazing thing about a bat is that they are able to change thier systems in a matter of hours .. where one day they are real active ... moving around in the houses .. maybe going out to hunt ... the heart beat picks up, they breath like normal.. the digestive system is working ....then a cold spell comes through... they are able to shut thier bodies down that quick going back into dormency stage

Now if the weather is not good in April ... they will wait till May

Critterman, I think you just described a northerner who migrates to Florida every year.

Just finished the last bat job for the year....

Bud, do you guys got snow yet? And do you rely on fur trapping in the winter to pay the bills?

Good grief....no. Winter is great for mice treatments and TAP insulation for attic upgrades.