Bat House Forum

[Terry Lobdell]

Tonight I had one big brown bat roosting in one of my bat houses! My previous record for early spring roosting was March 30th. I also noticed that tonight is the first night I've heard peepers this year.

[Shin-Thaibatmania]

GOOD JOB!!!! Guy:shock:

[Joe Spencer]

Fantastic Terry!  Today I got the rockets up with my neighbor and friend along with daughters.  Yet as I type this we're receiving 3-5" of snow.  Warmer times soon coming so I'm glad we got the two bat houses up with more info coming later.  Thanks again for the early occupancy news...

[Terry Lobdell]

Joe, I am looking forward to hearing how your new rockets do........I am especially intrigued by your ventilation design with the attic vents! The rocket without the attic vents, does it have regular vents in the lower third of the box?

[Joe Spencer]

No, Terry the non vented house has no vents in the lower third but I could easily add them later.  I wanted the two houses to be identical in every way with the exception that one could breath and have constant airflow with the airflow increasing with temperature rises.  This theory makes me think of what I noticed years ago at Greenfield state park in N.H.  When I arrived there they only had one bat house mounted under the extended gable end of their hot shower building which would allow no water in the bat house even if the roof failed.  What astonished me was that the bat house roof had failed when I took the bat house down in late October after the little browns left for hibernation.  The roof was not caulked or sealed in fact it was so badly warped/cupped that there was a 1/4" gap at the rear top of the bat house roof (higher end) allowing much heat to escape and yet it was loaded with bats.  It made me think that maybe airflow could be crucial in keeping active bats happy and coupled with Kent's feedback on seeing so many bats at or near roof peaks that there may be something to this.  This is in stark contrast to the original bat house designs from BCI and elsewhere which said that you must caulk and seal your roof well.  Of course we know we must keep water out but in doing so maybe we inhibited precious airflow which may be crucial.  Maybe it isn't crucial, I just don't know but it sure is worth experimenting with.  Another thing to note in my observations, I have seen many bats roosting in the gable end louvered vents of homes and new homes.  With the screening behind it, the bats could not penetrate the attic however, they would still utilize these areas for some time and be happy in the louvers.  The only connection I can make is that there was plenty of airflow there or was it only the temperature?  Who knows maybe I'm grasping at straws but with patience and multiple side by side experiments, maybe we'll find some evidence about the latter.  Kent have you seen any evidence of bats roosting in gable end attic vents/louvers?  Thanks, Joe...

[Terry Lobdell]

Joe, that exclusion I did last Sept. was on a house with both ridge and gable end louvered vents. One day there was at least 50 little browns roosting behind the louvers of just one gable vent! One of the louvers alone had 13 little browns behind it! I wish I would have had a good quality camera with me at the time........

I think they like a combination of heat and fresh air flow..........It's a delicate balance because if you get to much ventilation you lose your desired temperature.........

I know last summer when it got very hot and muggy my big browns especially sought out more ventilation.......

[LarryH]

We just returned home from an extended trip to Boston, MA, and were surprised to find not only that the Purple Martins had returned while we were gone -- and I hadn't put the house back up yet -- but the bats were already returning.  We've never had bat this early before. But then, it unusually warm for this time of year, too.  It has been in the high 70's.  I can say, though, we weren't that warm in Boston!

I have been working on building a nursery house to mount on the south end of the barn, but didn't get it finished before we left.  But, it appears that I'm going to have to get it finished soon.  I'm glad to see them little de-buggers back! 

 

 

[splaestro]

I asked around recently in my town to see what kind of experience other folks have had with bat boxes, and I haven't heard anything encouraging. One person reported no results after two years, and said she was told by

a bat "expert" that there are no species of bats around here that use bat houses.

I've asked her for more details on their house design and placement to see if maybe they got bad advice.

I know there are plenty of structures in this town that have had bats living in the attic or under the roof, so I would think they would be the kind to make use of a properly placed, appropriately designed house.

LarryH, you're not too far from where I live; what species of bats do you get in your houses?

BatMan, you're the one with one or more boxes on a barn in Union City, IN, correct? What have your results been?

Thanks, all.

Brian

[BatMan]

Yep you are correct, I haven't called up there yet this spring to see if we have any inhabitants yet, but as of last season there weren't any. Those people you talked to are misinformed, there are tons of Big Browns up there. I think the big browns were using my Grandma's house as a hibernaculum and my cousin has several hundred in his barn. I'll have to call up there to see what's going on with them.

[BatMan]

Update: All the bats that were living in my parents rocket house have disappeared. We haven't seen them for over a month now. Do you think they were using it as winter roost ? Wonder if they will return ?

[Terry Lobdell]

Brian, you should be able to gets lots of big and little brown bats where you live........

[splaestro]

Thanks, Terry, everything I've read indicates this as well. I'll just be patient...

[Joe Spencer]

Time will tell Batman.  Please re-inform us:  What color is your parents' rocket bat house?  Continued occupancy monitoring is essential.  Bats move and switch locations with season, temperature and possibly parasitic evasion.  Always good to give them options such as multiple bat houses in the same general area painted varying shades from dark to light.  Only with multiple options and behavior observations such as switching or leaving roosts can we be potentially objective with analysis and feedback.  ;)

[splaestro]

Hi folks, this is mostly a post at Joe's request to make sure my registration remains active.

I guess I can also report that I haven't seen any activity in the single chamber house that  I've had up for a little over a year now. At least, not any signs of sustained occupancy. I was gone for five weeks in the middle of this summer, and even when I'm here I'm not very regular in checking, but there hasn't been any guano or other signs that I can see.

Below is a picture of the box, mounted on the E side of our house (I had posted this and others last year when the box first went up, but that thread vanished along with some others when there was a server crash or hosting change or something).

It may be that this location doesn't get enough sun, or isn't high enough, or we're just not close enough to running water to attract a sufficient density of bats.

Does anyone have tips on how to check for past occupancy once the season is over?

[Terry Lobdell]

Sometimes there are faint urine stains on the landing pad. They are a whitish color.....There may be some guano on the ground you might have missed.......I once shined a light up and had 3 little browns roosting and there was no guano visible on the ground at all..........