Bat House Forum

[cloudman75]

I took photos of bat houses tonight and counted the bats. No freetails, 16 Little Browns, and my little tiny bat. Most of the Little Browns have gone, and all the Freetails. We have had cold nights for the last couple of nights around freezing. Anyone else have a report on numbers still with you?

Frank

[William Bagwell]

We had at least one flying around here just a few minutes ago. Wish I could say say it was using my bat house Have seen no sign of use since that week back in June.

Need to start watching the roosting space on the back of the 'people' house again. Last spring we had a loner using it for over a month before the small colony with pups showed back up.

William

[William Bagwell]

Not only are there at least two bats roosting in the eves of our house today for the first time in months. At least one has visited the bat house in recent weeks We were chastised several times today and can tell from the sounds that there are more than one.

Out under the bat house I found three guano pellets today. Not very fresh since they are almost solid white from mold, but they 'fell' since the last time that area was mowed just over a month ago. On top of the short grass not down on the dirt so no possible way they were left from last June.

William

[cloudman75]

Good news there William. With the return of warmer temps, 77 here today, I look for the return of some bats.

Frank

[marius]

Love hearing about other people's bats as winter moves closer. We still have some big browns as of early this evening, maybe about ten. They were packed into the middle chamber, which because the baffles have warped, makes for a tighter space ... also makes it hard to see/count them. I didn't know bats would stay so late in the year and wonder what they eat. Guess there are far more insects hanging around in cold weather than I knew. : )

[William Bagwell]

marius, which way are you baffles warped? Top to bottom, left to right, or both? I was asking about this a few weeks ago and never got an answer. Thinking about a house with a slightly curved front and wanting feed back before spending a bunch of time or money.

[marius]

Hi William ... You asked about this a few weeks ago? Sorry, I missed that. Our bat house has three chambers, two baffles. The baffles are warped from left to right such that they buckle in towards each other. This means all three chambers are equal width at the SIDES of the bat house, with the middle chamber being smaller in width at the middle of the bat house. (And consequently, the front and back chambers are wider in the middle, going from left to right.)

Early on when I noticed the warping, I thought we should fix it when the bats go into hibernation. However, since the bats returned this past August, they have been using the middle chamber as much as the other two and now that it’s cold, almost all of them are using the smaller width middle chamber. Two nights ago we could see about seven in the narrower middle chamber and three in the wider chambers, but who knows how many were higher up in the middle chamber. Last night all of the bats were in the middle chamber. This has made me think if we build out own bat house, we might make one chamber more narrow on purpose. However, the middle chamber looks so small, I wonder if the bats crawl in at the sides where it’s wider and then work their way in to the middle?

Spouse got some photos a few nights ago so I will try get him to use the rest of that roll of film, get it developed, and if the photos turn out, will post them.

Marius

P.S. I am laughing that your bats chastised you. Apt description. : )

[William Bagwell]

Thanks! And yes, chastised is a good description of what the bats are doing. Last year (2010) our little colony stayed virtually all summer despite my son working on a car (including welding!) almost directly underneath where the bats were roosting. This year with far less disturbance the (now slightly larger) colony only stayed a little over a week. With a few of the pups retuning for one day a week or so later and the two bats a few days ago. Guessing they outgrew the space as a colony and I plan to install a few real bat houses close to the roosting area this winter.

[Terry Lobdell]

William, I have some bat boxes with crevice sizes varying from 5/8" to one inch due to the natural warping of the one inch board baffles. The bats appear to actually like this varied crevice width.........quite often I will see 10 or 12 of them (little browns) jammed up in an area with approx. 5/8" width.

I believe Nate built a box that narrowed gradually towards the top..........I think Kent Borcherding has also......

The narrowing of a crevice space seems like it would mimic natural tree crevices and spaces under exfoliating bark.......

[kent borcherding]

The name of the bat house design you are referring to is the Oregon wedge bat house.

It was designed by a person who worked for the US Bureau of Land Management office in Medford , Oregon.

The BLM tested 3 designs - 3 chambered BCI , rocket box , and the Oregon wedge.

The houses were mounted at 9 different sites , if I remember correctly , and guano catchers were mounted under the houses.

The Oregon wedge was the most successful at all the sites.

The wedge design tapers from 1/2' at the top to 1 1/4" at the bottom. I like to make a 27" front and a 30" back.

Medford, Oregon is located near the Calif. - Oregon border and summer daytimes highes of 100 F are not unusual.

Without looking up my records I have at least 6 or more of the Oregon wedge designs at different sites - all have many bats in them .

If you like a good bat house that bats bat will use , spray the bat house with the material used to spray pick-up truck beds you will have a 20 - 25 year bat house with not maintenance other than knocking the wasps nest out in the fall . I prefer Perma - Tech spray and have it applied by a business that has knowledgeable employees doing the work . to many variables to try and apply yourself.

[William Bagwell]

If you like a good bat house that bats bat will use , spray the bat house with the material used to spray pick-up truck beds you will have a 20 - 25 year bat house with not maintenance other than knocking the wasps nest out in the fall . I prefer Perma - Tech spray and have it applied by a business that has knowledgeable employees doing the work . to many variables to try and apply yourself.

Wow, first I have heard of this technique! Inside too, or just the outside?

BTW thanks to Marius's encouraging conformation that bats will also use crevices that vary left to right I have started a new design of plastic house. A bit smaller than my first... Can post pictures of mysterious looking aluminum mold parts if anyone wants to see them

William

[kent borcherding]

spray just the outside of the bat house

The Oregon wedge houses I make prefer 24" wide - the BLM usually makes them 48" wide .

without getting off topic from the original post - there is a new Norwegian design now, that I believe shows promise of being a good design bats will use.

[cloudman75]

We have had nightime temps in the mid to low 30s recently. I took photos tonight. 5 of the 6 houses were empty. only six little browns left in the house with no ventilation. Looks like my bats are ready to go hibernate for the winter.

Frank

[marius]

Our bats left sometime in the past week. Not sure of date because I had six days of stomach flu and that kind of makes days blur together. Spouse informed me they were gone. We will miss them but this is out first year with bats so I keep thinking about when they will be back and that brings a smile. Plan now is to spend some the winter trying to read all the good information on this forum. Happy Holidays everyone!

[Terry Lobdell]

Marius, if it warms up again you could find some roosting.......I'm going to keep checking my boxes.......I checked tonight and there were none roosting.......