Bat House Forum

[cohutt]

Hello, who knew bat house forums existed? I'm glad I stumbled across this site; I have learned a good just browsing this evening.

Here is my situation:

I've constructed a large double maternity house that I am in ready to mount on pole(s) in my downtown backyard. I used this Batcon 4 chamber maternity house design: (EDIT: as new user I can't link to the plans@ batcon.)

I expanded the dimensions to roughly 30" tall x 23" wide, built two and went ahead and fixed them back to back. The space between the backs brings the total chambers up to 9 (2 x 4 chamber houses + the space between).

I figured the larger, deeper house with multiple chambers would provide more temperature "zones" depending on the season and time of day. I plan to mount it 16-20 feet high between two poles in the back yard. I have larger hardwoods to the east/southeast of the spot and pretty much wide open to the south and west.

After it was assembled I stained it a very dark solid grey (actually almost black) and added a metal roof with some overhang for mid summer shade/heat relief.
The mean high temperature here in NW GA is 90.8 degrees during the dog days of summer; even though I'm in north Ga I'm is virtually the lowest point north of Atlanta @ 600 ft above sea level and the temperatures tend to run a little warmer because of it.

This is the current state of the project as of yesterday evening, complete with "vintage" roofing.

(EDIT: as new user my picture can't be linked.)

1. Is this color too dark, considering the depth and mid day shading of the overhanging roof?
2. To what orientation should this be mounted? east/southeast? The late afternoon sun would bake the house into the early evening during July/August when it cooks here.

(edit: I will post the picture whenever I ht the required post count)

[cloudman75]

Hello,
I am in Lithia Springs, about 20 miles west of Atlanta. What town are you in ? I can give you some of my views if I know that. I also would sure be interested in seeing the bat house photos when you post them. I have 5 houses installed right now and have been watching bats about 8 years . Just let me know if I can assist in some way, and welcome to the forum. I have one house I just painted a royal blue, almost black. It was a lighter blue and was well used as a materity house for pups in late March and early April. I have another maternity house that is dark blue on the upper portion and a lighter blue on the bottom portion. It has been well used. Then last year I built some unpainted cedar houses which were not heavily used as new houses. My old 3 chamber OBC store bought house seems to be the little brown bats favorite. Just tonight I have 4 bats here which apparently do not go to a cave but they will leave when it gets in the 20s at night. When it warms, they show up again. I recently posted some photos so take a look if interested. My houses are all pole mounted at near 20 ft. I have 3- 3 chamber houses a large 5 chamber and a smaller 5 chamber. In general I have found that one color here does not satisfy the needs of our bats. When it gets up around a hundred the darker houses are not used until it cools down. They do need some heat in late March and April. I have 3 houses
facing south, one facing west and one facing North. All have been used in the past.

Frank

[cohutt]

Hey Frank-

I'm north of you In Floyd county-

I hadn't stopped to consider that one size/color might limit what I can attract at different times of the year. It makes sense though.
Interesting idea, the graduated color scheme - dark @ the top, lighter at the bottom. It makes sense and might be something to consider with this one.
What do you use to mount yours @ 20ft?

[cohutt]

I found my answer:

I used a tractor, a come-along, and a boat winch to raise the extra heavy 5 chamber large bat house on a 1-1/4 inch schedule 40 pipe that was 21 ft long.

I was considering the galvanized schedule 40 as well; two poles with the big house bolted between them. I went ahead and added exterior "mounts" to the sides so this would be easier to do without affecting the integrity of the house body.

[William Bagwell]

Welcome! Hopefully Joe will unblock you soon so you can post pictures. (Constant battle with spamers who want to sell us every thing under the sun except bat houses...) Feel free to send bathouse pictures or links to the address in my profile and I will post them for you.

Are these the four chamber plans you started with and modified?
http://www.batcon.org/pdfs/bathouses/Fo ... ePlans.pdf

Batcon's color recommendation.
http://www.batcon.org/pdfs/bathouses/ColorRecs.pdf
Virtually all of Georgia is in the "Dark or medium shade of paint" area. I put up a slightly too dark, plastic, un-vented bat house on a pole in full sun last spring and it was used briefly twice during the season.

First use was probably bachelors trying to be near the small (7 plus pups) colony that was roosting in the eaves of our house. At least one likely two based on the quantity of guano produced. He (or she or they) stayed just over a week left at the same time the main colony left. Very disappointed my bats did not stay all summer like they did in 2010 when it was only 4 plus pups. At some point later in the summer the pole mounted house was used once more for just a day or two.

If yours are vented you should be just fine with the dark gray.

[cohutt]

I didn't realize that I could have uploaded a pic directly last night when I posted.

The monstrosity as it sits awaiting possible color adjustments and mounting is attached although the pic quality is greatly reduced.

[cohutt]

William,

Thanks for the welcome- I am global moderator on two forums so I understand the constant spammer fights. (The gateway to open the membership here was pretty thorough so in hindsight I don't know why I was surprised I couldn't link yet. )

Yes, the lovely crate above is an expanded double version of the batcon plans you linked, taller and wider per the original post. I vented as instructed but really wasn't sure about their description for the middle chamber. I ended up leaving a modest space at the very top between the two houses- basically the divider doesn't quite make it to the top. All dividers including the backs have access holes between them, 2 x 1 1/4" each I think.
Thanks for the color confirmation- it sure looks dark when it is freshly stained.

I note you are from N GA as well- any relatives in Floyd county?

[cloudman75]

Up in the Rome area, Floyd County, you should be OK with the color you have on the house. Since it is back to back I would face it South so as to have a north exposure also. East to west would be my second choice and either one OK.
The bats can go over to the cooler side if they get too hot. I do think you need another smaller house perhaps a three chamber painted light blue, or unpainted. Your house really looks heavy so the two poles or post would be the way to go most likely. William might give you some ideas as I have never used two post. Terry also has installed a lot of bat houses so you should get some good advice. I have three houses mounted on a hollow pole I built, but I have a steel channel in concrete, a pivot at ground level and pulled it up with a tractor from a rope tied in a tree. I bolted the post to the steel chanel. I always work alone so have to do the best I can with what I have available. I would put up a smaller house so that when it gets really hot the bats can use the cooler house. I have posted some photos on here of my bats hanging on the landing board in daytime because they are too hot even in an unpainted house. Good luck and keep us posted here on the forum.


Frank

[Terry Lobdell]

Welcome! I am in NWPA with obviously a cooler climate, but have learned a lot about temperature control in bat houses especially for big brown bats. They need consistent temps and lots of ventilation......

You may not get big browns but based on a lot of experience, your back to back mounting method is definitely the way to go for any species in any area............

I was not clear on how much of a gap you have between the two boxes.........I would recommend 3/4" and definitely no more than one inch.........

The access slot in the backs of each box is a huge factor that bats love so they can move internally from box to box.....

If I understood correctly, your spacers between each box stop before the top? In extremely hot weather bats love a crevice that is open or mostly open at the top......Bats will also enter and exit through these higher access points of a box.........

A highly ventilated space between the two boxes will give you a greater temperature variation between the two boxes.......

Temperature variation within a bat box is very important so that they can move around and find their desired temperature in any kind of weather......So that in cool weather they can find a crevice that is warm enough and in extremely hot weather they can find a crevice that is cooler with plenty of ventilation........

I agree with everything Frank and William have told you so far.......Another thing you might want to consider if you do a north - south orientation is to paint the north facing box a lighter color than the south facing box..........

I have found that with a large box like you have there it is possible to provide all the temperature ranges bats need.......

My experience has been with little browns which can tolerate very high temps with little ventilation and big browns that need lower and more stable temps with a tremendous amount of ventilation..........

I will post a link that shows more about ventilation.......

[Terry Lobdell]

Here are pictures of a chimney mounted box with spacers.....the bats love to roost between the box and the chimney in very hot weather! I should also note that I do not build single crevice boxes anymore......This box works because it maintains stable temperature being mounted to the chimney........if it were mounted to a pole it would cool off too much at night.......
chimney-mounted-bat-house-with-big-browns-t555.html

[cohutt]

Hmm, I have a large SE facing chimney that might work for a similar set up for a 2nd box.

Yes, I used 3/4 spacers between the boxes. They don't go all the way to the top, I'll have to look again to recall exactly how much space is there.. If it is too small I could always open it a bit before I mount these.

[JR0835]

Your bathouse.
Jack

[cohutt]

?

I can see the attached file fine in the post up the page, but thanks.

Terry,

The 3/4" space between the boxes is ventilated well.
I didn't caulk the joints between the spacers and the two boxes
The side spacers don't go to the very top and the horizontal spacer between the tops of the houses leaves a couple inches on either end. The end of the horizontal spacer is the unpainted wood in the picture.
Additionally, there is no wooden "roof decking" under the metal roof between the two houses and over the houses, there is some gap between most of the metal roof and the wood decking underneath.

This should provide a good thermal "gap" between the houses when the summer sun is toasting the southern facing box (I think I'll go north/south facing when mounting).

Comments?

[William Bagwell]

William,
I note you are from N GA as well- any relatives in Floyd county?

Possibly, though there are several sets of Bagwell's that do not tie in the US. I'm originally from Cobb county currently in living Pickens.

Only 600 feet of elevation and north of Atlanta? What quarry pit do you live in?

[cohutt]

Another question If you guys don't mind me pestering you......

Based on a wider perspective of the same photograph as the close up, is my roof overhang overkill? The south facing side will benefit as it will keep some of the hottest sun off the top half of the box in July and August. Should I trim it back a bit while it is still on the ground?

(Sorry, I'm still trying to get the right size for the picture attachments until I can link to my photobucket galleries)