Bat House Forum

[moabjen]

I live in SW Utah and it gets hotter than blue blazes (up to 110 although high 90 are average for 60+ days during the summer). The eve of the house may shade the house a bit, if I put it on the west side, the south side of my house is the gable end, so no overhang. I have a garden pond in the back yard and live within 200 yards of a creek. I also see bats around the street lights. The house is the only place for the bathouse, no power poles. Hanging the bathouse is a commitment for me because I have stucco and don't want to put holes in it to no avail. Will it be better to have afternoon shade? Or, because it is so hot here, can I put the house on the east side of my house that gets good shade (although that is where we hang out, will that keep them away?) Lots of questions....thanks for a reply.

[cloudman75]

I checked on Utah and see that you have several bat species that could use your bat house. I'll give you my opinion based on my several years experience with little brown bats which you probably have in your location.
Little browns like it hot and 110 degrees is not too hot provided that they have a little air ventilation. I had them in my attic louver which got hotter than that. The maternity colonies need it very warm for the pups. I had a house mounted under the eves of my home facing East so that it was shaded in the afternoon. It was very sucessful as a maternity colony.
I moved it off my house because of the guano,(bat poop) and urine dropping down on my carport. I would advise you to mount it on a pole in the yard for better air movement due to your hot location. I would not mount it on the house as you certainly don't need the extra mass or heat from what you described. I am in Georgia where it gets hot and humid. I use metal poles like galvanized water pipe which come in 21 ft lengths.
If you have big browns, they don't like it so hot from what I have read. I have no experience with big browns, but there are plenty on this forum who do.
My little browns got plenty hot under the eves facing East with shade in the afternoon. Place your house where guano and urine won't be a problem. I sit in a chair at dusk and watch my bats exit from two bat houses. They come within 3 or 4 ft of me when flying out and it does not appear to bother them. I try not to be too noisy but normal conversation seems to be OK with the bats. I have 82 right now total in two houses on poles. I'll be anxious to see what happens with your bat house. Also I hope you will get good advice from the members of this forum with more experience on your particular bats.
Good luck.

[AlienSpy]

Can it get too hot?

In my opinion, this is an important question. And, one to which I can't find an answer.

The focus is on making a bat house hot enough to accomodate nursery colonies.

Since the focus is on making it hotter, no one seems to think about the upper limit to acceptable temperatures inside bat houses.

If that upper limit is in the vacinity of 118 degres F, since temperatures rise very rapidly to temperatures above 125 degrees in enclosed spaces exposed to direct sunlight, it seems to me that too hot is almost as possible as not hot enough.

Is anyone aware of experimentation with temperature data loggers inside bat boxes?

Does anyone know if bats can tolerate temperatures above 115 degrees F? If so, what is the maximum temperature they will tolerate before vacating?

[Joe Spencer]

Correct, it is too hot at these extremes. Although little brown bats are much more tolerant of heat than big brown bats and have been recorded rearing young in temperatures as high as 104 degrees, they prefer 80 to 90 degrees. Big brown bats, however, are known to abandon roosts when the temperature rises above 95 degrees. At a sustained 110 degrees, little brown or myotis bats in general will abandon a roost. I have seen bats (nursery colonies) roosting in barns at the roof peak in the morning and down closer to the soffit area in the late afternoon with temperatures peaking.

[AlienSpy]

Thanks Joe!

From what you've written, there isn't a lot of difference between bats and birds when it comes to the upper temperature limits on artificial housing.

My experience with artificial bird housing leads me to believe that by June in South Carolina, Tennessee, Arkansas and states of similar latitude, most bat houses end up being too hot, not too cool.

Because bat houses are open at the bottom, they automatically have more ventilatin than most bird nesting boxes.

But, when the sun hits a dark surface, the surface can quickly go over 140 degrees. And, that transfers into the inside.

Do you know of anyone who has used temperature data loggers to test internal bat house temperatures with outside ambient temperatures?

Thanks again!

[Joe Spencer]

Do you know of anyone who has used temperature data loggers to test internal bat house temperatures with outside ambient temperatures?

Thanks again!

Yes, Jim Buzbee but it appears he hasn't done it in a long time in his bat houses: http://www.batbox.org

Up to date here with temp loggers with his home: http://wx.homelinux.org:10235/cgi-bin/wx.pl

I have done some temp. logging over the years with simple indoor outdoor digital thermometers with the outdoor sensor taped to a stick and stuck up into the bat house. In all cases on those bat houses with enough thermal mass the inside of the internal chamber core of a megarocket bat house with multiple chambers was 10-30 degrees cooler than the outside ambient temperature depending on the time of day of recording. It was also substantially cooler on the inside core/chamber than it was on the outside most chamber understandably. Basically, build a bat house with enough roosting partitions and most importantly thermal mass and you can meet with success in Southern climates as well. BCI's charts still recommend a darker colored house for many southern states.

[jbker]

I believe it can definitely get too hot. About 3 summers ago, I had a single chamber house on the north side of my home with about 100 evening bats in it. It was July here in S Florida and the temp was about 95 high and 75 low. When the afternoon sun was bearing down on it, some of the bats came out on the landing platform and appeared distressed from the heat. When they egressed that evening, several crashed to the ground and had to climb back on a column to get airborne. Talked to the Marks at Florida Bat Cons. and they said it was the first year they had reports of too hot bats.

bernie , SE Florida, currently housing over 400 brazilian free tails in a hurricane resistant 12 chamber rocket that I designed and built

[Joe Spencer]

Agreed Bernie. Would you be able to post a picture of this large rocket bat house for us? Thanks


UPDATE: HERE is Bernie's rocket: rocket-with-over-400-bft-s-t706.html

[jbker]

Here is a pic of the first bat house I built when it was mounted on the side of my house with evening bats. They have no odor compared to BFT's which have a very distinctive musky odor. The guano of neither really smells bad until it gets wet The bats hanging out of the house in the afternoon is not normal. The whole colony departed that night to never return



Ok Joe, you probably will have to fix it again. Tell me once again what I missed trying to post photo.

bernie

Bernie, just like this without the quotes: "[img]"http://i177.photobucket.com/albums/w211/jbkerr/hotbats.jpg"[/img]"
You highlight the URL example: "http://i177.photobucket.com/albums/w211/jbkerr/hotbats.jpg" and then click on the "Img" button above the compose/post box which will then automatically put these two tags on the beginning and end of your highlighted url. OR Bernie, you may just select Upload attachment which is located to the lower left of the post/compose box. This will allow you to browse your computer and upload your picture as an attachment bypassing the image host and you don't have to worry about URL's. It is easier this way but it will place the picture on my webhost server and add to our bandwidth and disk space. No problem for small photos such as yours but larger ones yes. You may use either way. I hope this helps you and thanks for this valuable photo contribution. Very informative Bernie...