little brown bats

Yesterday with our outdoors study class we checked the game camera to see if it was recording the coming and goings of bats and found that it had captured nothing all week. Our conclusion was that the camera needed to be moved closer to the nesting site simply because their bodies are so small they may not trigger the motion sensing mechanism in the camera without it being closer.

We also did a rough estimate of the number of bat turds in the collection box. Students had made guesses about the number ranging from 50-60 to 150 individual poops. To attempt a more accurate count we tried using sticks to gather them in groups of 10 on the bottom of the box, but that proved impossible. 

Our second attempt was to weigh a number using a gram scale and then extrapolate to the whole weight of the bat turds gathered in the box. But they were too light to measure accurately in grams. So our third try was to count the number of turds in a table spoon and then measure the number of table spoons in the box. 

The resulting estimate was a surprise to the students as we found there to be 165 turds to a table spoon and approximately 7 table spoons in the box for a total of 1155, far surpassing student guesses.

With approximately 50 bats in the nesting area pooping over an 8 day period we learned that the bats while nesting poop about 3 turds per day. Each small turd represents hundreds of small bugs harvested from the night sky.

To make future observations easier, we marked a grid pattern at the bottom of the box so we can quickly observe the number of turds per square inch. We were first alerted to the presence of bats by the pile of guano left below their nesting site, and the box will allow us to observe a hoped for relocation to more permanent bat boxes.

Next week we begin assembling bat houses.

Make, fix and create...