Bat House Forum

[IowaNate]

  I finally got the "go ahead" on my bat house project in two areas near my home. The parks project manager wants me to choose the sites at each location, and draw up a rough diagram of the mounting design. He said I could probably put up a dozen houses at each site.

  The first site is a spring fed creek that is about 20 feet wide, and the second site is a 10 acre lake that is fed from the Cedar River. Now I just have to choose a few sunny locations away from trees.

  I need the bat house design to be lightweight, inexpensive to make and produce a few in a day's time. I am leaning toward two- 3 or 4 chamber nursery houses mounted back to back on one a 4X4 post. I am planning on a total of four houses at each site to start with. And I need the houses to last as long as possible. The simplest option is a house made of 1/2" plywood and 1X4's. A 1X4 gives me three chambers at 3/4, 3/4, and 1" or 3/4, 7/8, 7/8" without cutting or ripping the 1X4 down. The houses would be 16" wide and 24" tall to get the most from each peice of plywood.

     Any comments or suggestions would be greatly appreciated!!!

[IowaNate]

  I calculated the cost of each bat house (wood, pet screening, stainless staples, screws, and paint) and come up with about $14 per house. Of course the post and mounting hardware will be extra. I decided that I will rip the 1X4 down to 3.25" to make each chamber 3/4", even though cutting that 1/4" off can be a pain and time consuming with a circular saw. Each chamber will be within BCI's guidelines measuring 14.5" wide and 21" tall.

   Given the hundreds of bats I have seen flying where these houses will be installed, they should be occupied by next summer. I should be able to be mount all of the houses within 30 feet of open water. The houses should be able to hold at least 200 bats each.

   These areas also seem like the perfect spot to put rocket style houses. Perhaps I will give them a try after the first few houses are hung. And if these houses are successful, there are 3 other parks along the river that I will make another petition to hang bat houses in. There are no bat houses hung in the public parks of Cedar Rapids, yet most are perfect for bat house occupancy. I was very surprised at the Parks Department's enthusiam and willingness to let me hang some houses. Two emails and a short phone call was all it took!

[IowaNate]

  I can get treated 4X4 posts that are 16 feet long for $16. It should be easy to make a mount that extends a few feet above the top of post to hang the houses at least 15 feet up.

[Terry Lobdell]

Nate, that is great news that you got the go ahead for this project! The pole extension method is exactly what I did recently. I had a treated 4x6x16 sunk 3' in the ground. I raised the total pole height by 4' by attaching a treated 2x6x8. I then mounted my bat house to the 2x6. Would have taken pics but it was a rainy dreary day.

[Terry Lobdell]

Some thoughts on durable wood exteriors: If you have access to any eastern hemlock it is very weather resistant. I noticed the bat houses at the state park this summer had hemlock outer shells with flat roofs and no shingles or tar paper. The hemlock had not rotted at all and had actually weathered a dark color.

My parents have a barn built in 1902 with all original hemlock siding. A lot of it is still held on with the original square nails!

In recent years I have gone more to metal exteriors for longer life but they are more expensive and time consuming to make.

Next year I am going try some exteriors of larch which is even more rot resistant than the hemlock. My hope is that even as the dark stain weathers away the exterior will still stay dark enough for proper heat absorption.

[IowaNate]

 Here are the sites that I have chosen and am proposing to the parks department.

   All of the photos show a red dot where the poles will be mounted.

  Below is the first site next to McCloud Run creek. The stream is just 30 feet to the West of the proposed site. It is in the open and receives good sunlight throughout the day.



    Below is the second site at McCloud Run creek. The creek is just 15 feet to the East of the proposed site, and is free of trees within 40 feet.



  Below is the most promising site at Mohawk park. It is on the tip of a peninsula of a ten acre lake that is river fed. I outlined the shoreline in purple to show the contrast better since the snow makes it difficult to see. The houses will be 30 feet from the nearest trees and 15 feet from the water. This site will have two 4X4 posts spaced about three feet apart with runner boards across them to mount the houses on.

[Joe Spencer]

These sites sure look promising Nate!  The park sites I have approached have usually been very receptive too however, I've had to foot the cost of the entire project.  Good luck with this project.

[Terry Lobdell]

Nate, how far are these sites from your houses at the nature center?

[IowaNate]

These sites are about six miles from the Nature Center. But they are within 1.5 miles of my house. The close proximity to my house means I can check them much more often and keep slightly better records on the bats once they start using the houses.