Bat House Forum

[IowaNate]

  I am currently recording the temperature of the rear chamber of my three chamber house mounted on my home. This bat house is located 2.5 feet from my occupied house with 9 big browns in it. They are identical height, width, distance above the ground, and both face the same direction (North).  I have one sensor placed at the top of the chamber and one sensor placed an inch below the bat house. Since this house and my occupied house face North, they are mostly shaded this time of the year. Most of the house temperature gain is from the air temp and heat coming through my wall and being transferred into the bat house.

   The purpose of this study is to see what temperature my big browns are currently "hibernating" at, without disturbing them but matching every constant of the occupied house.

   The thermometers are Acurite 00887 digital thermometers with ten foot remote sensors. I made sure they read the same temperature before placing them in position.

  I will take readings every hour starting at 2 pm today and update this topic with my findings.

   2:00 pm -   42.1 outdoor       44.6 bat house 

   3:00 pm -   43.0 outdoor       42.3 bat house

   4:00 pm -   40.3 outdoor       40.8 bat house

   5:00 pm -   37.0 outdoor       39.0 bat house

   6:00 pm -   35.4 outdoor       36.9 bat house

   7:00 pm -   33.8 outdoor       35.4 bat house

   8:00 pm -   31.5 outdoor       34.0 bat house

   9:00 pm -   30.2 outdoor       32.7 bat house    

 10:00 pm to 6:00 am - no temps taken

   7:00 am -   24.4 outdoor       28.0 bat house

   8:00 am -   22.5 outdoor       25.0 bat house

   9:00 am -   23.0 outdoor       23.5 bat house

 10:00 am -   25.0 outdoor       24.4 bat house 

 11:00 am -   26.8 outdoor       26.2 bat house

 12:00 am -   29.1 outdoor       28.2 bat house

   1:00 pm -   31.1 outdoor       30.4 bat house

   2:00 pm -   31.3 outdoor       31.6 bat house

   3:00 pm -   30.4 outdoor       33.3 bat house

   4:00 pm -   28.8 outdoor       33.1 bat house

   5:00 pm -   27.3 outdoor       31.3 bat house

   6:00 pm -   25.7 outdoor       29.7 bat house

   7:00 pm -   25.0 outdoor       28.0 bat house


 

 





   The data is much easier to understand on my graph below. Horizontal indicates time, vertical indicates temperature. Red is the bat house temp and black is the ambient air temp. This is from 7 am to 7 pm, November 27 2007.

 

[Terry Lobdell]

Interesting.........where did you find the thermometers and sensors?

[IowaNate]

 Terry, I got these thermometers at Lowes* in the gardening section. The sensors are about 3/4" long and 1/2" wide and deep, attached to the display unit by a thin ten foot wire. I tested them against two mercury thermometers that I already had, and they read within 1 degree of them. I just wish they logged the temp every hour so there wasn't a data gap while I was sleeping!

  I will keep up with the study today.

[Terry Lobdell]

Nate, thanks for sharing this info.........I've often thought about building a bat house recessed into a wall of my house that might maintain temps suitable for hibernating bats......your temperature plot and  info on equipment will be very helpful for future projects!

[IowaNate]

   I hope this info helps you, me, and many others to perhaps keep a few species of bats year-round. I suspect that the temperature is a bit higher in the occupied crevice of the other bat house due to the bat's body temperature and them being so tightly packed together. But this data from the other house being almost 100% identical in every way and only mounted 2.5 feet from the occupied house should show one aspect of thier choices for hibernation temps.