Bat House Forum

[Terry Lobdell]

Here is a picture of what I call a T-Post.........a double layer of one inch rough sawn boards with a french cleat strip along the top to easily mount more than one bat box.

The actual post is made of 2 larch 2x6's sandwiched around a 1x6 inch larch board. The top mounting cross piece has a 1x6 extending up through the middle and splicing down through into the post. For this board I used hickory for strength.

Shown in this picture is a small 3 crevice box on the left and an experimental rocket box constructed of a rough sawn 2x4 inside a section of corrugated black drain pipe. This corrugated pipe box was more trouble that it was worth and has no usage yet.......

[Terry Lobdell]

Here is a closer view........One thing different I plan on doing with the next T-post I build will be to make the horizontal mounting section out of just one layer of boards instead of 2 layers. The vertical connecting board I will double for more strength...........This one I found to be just too flimsy when I mounted the bat boxes.........

[Terry Lobdell]

A view with more boxes.......The box on the right has a front of asphalt shingles for more heat gain.......

The back side has 4 boxes mounted........the backs of all 7 boxes on this structure have a hole or slot allowing bats to access any box by moving through the structure internally.

The horizontal cross pieces consist of 1x6's with 5/8" gaps in between.........

[Terry Lobdell]

Here is a view from the side showing how the bat boxes hang on the french cleats. Only the corrugated rocket box is permanently fastened. The other 6 boxes just hang with no screws or nails and can be easily lifted off.........

Tonight I had 4 bachelors using these boxes.

The shorter of these boxes were made from a plan to build a 3 crevice bat box out of a 1"x6"x8' board. I will post the plans soon!

This structure provides a lot of options for easy experimentation of different bat boxes.

[Terry Lobdell]

Part of this experiment is to see if my little browns will use these small boxes. Last year I did a program demonstrating how to measure, cut and build a small bat box from a single 1"x6"x8' board. These boxes are the ones I built practicing......the baffles are 13" and 14" in height. The surface is simply rough sawn wood with no scoring or saw kerfing.......the bats seem to have no trouble at all hanging from it.

Another reason for this experiment is to see how small of a box little brown bat mothers and pups will use. Many plans show a single crevice box which is fine mounted on a building but loses to much heat when mounted on a pole.

I built a bunch of single crevice boxes a few years ago and now they are useless unless they are mounted on a building where there are big brown bats.

My thinking is that small 3 crevice boxes like these will make better starter boxes for both big and little brown bats than larger single crevice boxes.

I am also going to make some boxes out of some 1"x6"x10' boards. This would give baffle lengths of about 17" and 18".

[Terry Lobdell]

This is another view of how the boxes are mounted with french cleats. I actually only have french cleats on the top. The bottom strip of wood is just used as a spacer here and is not fastened.

For larger boxes I use the french cleats on the bottom the same way the top ones are shown here for maximum strength. Additional metal brackets may be added if needed.

[cloudman75]

I like that T post concept. I agree that the top board looks a little light for all the weight you have on it. I plan to
try one this fall once the weather cools. I plan to use your T post idea for my recycled potato bin box.
Great photos. I dropped my camera and broke the toggle switch. It is stuck in the auto position so after looking at your photos, I ordered a new camera last night on the net. Naturally after buying one, I found it 12 bucks cheaper on amazon.
At least I will soon be able to take better night photos of the bat houses by using some manual settings. I am thinking of a way to crank a bat house up into the air with a hand boat type winch. At my age I have quit climbing ladders for good
if over 6 ft. I truly believe that we need light colors or no color in my area for bat houses. The bats staying with me
in mid 90 weather re-enforces my belief. Also they have avoided the dark colored house without ventilation since it got hot. Yet it is the first house used in winter and in spring until it warms. It's fun to experiment and I can see you enjoy it
from all the bat house installations. My colonies will normally stay until about Nov. depending on when freezing temps arrive. They sometimes will leave a couple of weeks in August, then come back. I was glad to spot a few freetails in with the little browns. I have quit trying to count the total since they are in two houses and also I had a family of blue birds
which resented my presence next to their house. The 4 little ones left the nest this week. I am still working on my recycled potato bin bat house. It will have soft white pine baffles built as a unit, then slipped inside and screwed to the sides. they will be about 8 inches shorter than the box. Also the top 8 inches will be an attic square about the size of the box with a hardware cloth floor.Two sides and the top are alreaded provide with screening. It will have access from a 1 inch slot on one side into the attic. I will post some photos when I get back to work.
I plan to put in a ceiling and a metal roof over it. I am just using materials on hand to experiment .(junk)
Also I am sold on the french cleats you use and have seen some videos of carpenters using them for heavy objects mounted flush on the wall such as a kitchen cabinet.


Frank

[Terry Lobdell]

Frank,
I just built a box earlier this summer that can be raised and lowered with a hand winch. I will post pictures of it soon. It is part of a kit to be used for purple martin houses. Mine cost $69.00 and has a brake. There is a lower cost one available for around $45.00 but does not have a brake. I'll try to send you the link.

[Terry Lobdell]

Shined a light up in these boxes tonight and every box had at least one little brown bat with the exception of the corrugated pipe rocket box which had none. There were a total of 12 bats in the 6 conventional wood boxes.

[Terry Lobdell]

Shined a light up in these tonight and had 20 little browns roosting throughout........they were in the 6 conventional boxes........none in the corrugated pipe rocket box.......

[cloudman75]

Glad to hear about the bats, a reward for your efforts Terry. Take a look at the photo I took before the bats left this eve. at dusk. See the blonde bat? The bats on each side appear brown, so I think this bat is a lighter color. It was more evident in the photo in my camera.

Frank

[Terry Lobdell]

Frank, yes I see it! Looks like it might be a big brown? Mine are pretty light in color..........

[Terry Lobdell]

Had 40+ little browns roosting in this structure tonight..........all in the conventional style bat boxes.

I am liking this T-post structure more and more for observing bats. It is very easy to stand underneath and see how and where they are roosting.........when there are a lot of bats roosting in it you really get some good insight into their preferences.....

These boxes all have rough sawn one inch board baffles. No scoring, no saw kerfs.....

The baffles also have some warp which I'm starting to think might even be preferable to the bats..........

Because of the warp the crevice size varies usually from 5/8" to 7/8" even though I try to maintain 3/4"......

Some are even half inch in certain spots and some crevices are an inch.....

I am still a firm believer in 3/4" crevice size, but have noticed these bats seem to love the places that are 5/8". I'm pretty sure these are little brown adolescents.........

[Terry Lobdell]

As of mid August I now have about 50 little browns using the boxes on this structure. I even had 2 in the corrugated black pipe rocket box. Yesterday I observed lots of big brown bat guano underneath so now they are using it too.......I expect my numbers of little browns here to decrease each day now though as they begin migration........

[Terry Lobdell]

Most of my little browns are now gone..........I've got maybe 30 spread out among my different boxes from about 110 after pups were born........came home from work last night and there were about 10 total in these boxes........interestingly all were in the south facing boxes.........no doubt because they absorb the most heat during the day.......all the bats were roosting tight to the tops in the middle or back crevices.......