Fall 2007

Fall 2006

David Cramer wanted to work on animal behavior but he didn't want to study bats.  He wanted to work on a captive colony of Brown lemurs (Eulemur fulvus) at the Noah's Ark Animal Rehabilitation Center in Locust Grove, Georgia.

Spring 2006 

Kristen Bray was working on extending previous studies by capturing bats at several locations in Georgia.  Unfortunately, the bats didn't cooperate with us, so we weren't able to capture any.  However, we did get several nights of recording to allow us to look for patterns in the bats foraging behavior at our recording location.  The interesting thing we found is that there is a lot of variability in the use of the site, depending on the exact time of the recording.  Sometimes the bats were foraging and other times they were just flying overhead.  We definitely plan to examine this pattern in more detail in future semesters.

Nicole Wise was working on a similar type of project, except she was planning on looking at the behavior of different species of bats.  To do this, we also needed to capture the bats, so her project suffered from the same problem of bats that refused to be captured.  However, while trying to capture bats we did notice some interesting behavior at her site.  The bats repeatedly engaged in aggressive behaviors, where one bat would chase another while emitting buzzes or other distinctive ultrasonic calls.  These specialized calls seem to indicate that the bats were communicating with one another.  Below are some examples of the "strange" calls we got during her recordings.

The calls shown below are not particularly different from their appearance, but when listening to the sounds and observing the bats' behavior, there is some suggestion that these calls are not normal echolocation calls.  We don't know exactly what they are, but that's definitely a question we would like to answer!

Fall 2005 

Both Lee and Nikki continued their work this semester.  In addition, Nikki began looking at calls of males and females to try and determine if we could isolate the variables that differ between the sexes.  Her analyses showed that not only did the calls of males and female big brown bats differ, but that those differences are most pronounced in calls that were particularly short (less than about 5 ms in duration).  These results were submitted to the Georgia Journal of Science and were published in that journal at the end of 2006.

Roshenea Wade started a project that will continue looking at improvements to the Matlab analysis routine, as well as analyzing the echolocation calls of big brown bats in Georgia and Ohio to see if there are difference in the calls of bats in the two states.  Preliminary results suggest that there may be geographic differences in the calls, suggesting that calls differ enough that we might be able to determine where a bat was from based on its "accent".  Further analyses of these results will allow us to examine these results in more detail.

Summer 2005

Lee Camp continued the work that Christina began - instead of going to lots of different sites a few times, Lee has tried going to a smaller number of sites many times to give us more way to find patterns in the bats' behavior.  He has spent a lot of time wandering around fighting off the wonderful Georgian mosquitoes.  While we had hoped to be able to capture bats so that we could determine what they were doing more clearly, we still found that there did seem to be some relationships between various environmental variables and the behavior of the bats.  We hope to examine this in more detail to get a better idea of how the environment might be influencing the behavior of the bats. 

At the same time, Nikki Sawyer began work cataloging the Matlab analysis programs.  She is looking for ways to improve the analyses so that we can get more information from the bats calls.  She also has the patience to wade through thousands of bat calls!  As a result of her patience, we have improved several aspects of the software, allowing us to analyze the calls more accurately.  This is a continuing process because there are a lot of ideas we have developed to increase the speed and accuracy of the software.

Summer 2004  

Christina Walters spent a lot of time traveling around Georgia trying to find the environmental conditions that would predict when and where the bats were active.  She also took part in mistnetting on several nights, and on one night we caught 20 bats in our nets!  This was the first set of calls where we could record information about the bats' sex, weight, and species, meaning that we can get a better idea of differences in the echolocation calls of bats.  The calls we recorded this summer are going to be useful for many other students to use in the future.

Spring 2003

Nakeeta Sims did work trying to find more bats as well as writing a manual for the software that I use for analysis.  This will make it easier for future students to use the software, since they'll have a comprehensible manual to go along with the programs!

Fall 2002 - Spring 2003 

Pam Coltrain (on her own initiative) worked with a local school to set up a bat house research project.  Click here to see more information about the project and for updates on its progress. 

Summer 2002

I had the opportunity to work with two different students, both of whom helped me surveying bats in the local area.  Their work was the first step in the process of building up a good collection of bat calls and behavior for analysis.  

Here are pictures of them with the microphones we use to record the bats (they're wearing headphones so that they can hear the sounds that the microphones make to indicate that bats are flying around.  Here are their pictures, although they probably won't forgive me for putting these up! :)