Our experiment has progressed substantially this week with the start of the burrow condition. Our team has observed the four rats during two sessions each, one session in the morning and one in the evening. Initial difficulties occurred as we tried to use the same burrow for all four rats. During the first session with the first rat, Bianca marked the burrow itself therefore compromising the experimental control of the subsequent sessions. My partner and I decided to make eight identical burrows for each rat and session. All burrows follow the design outlined in the method section and are constructed from cardboard tissue boxes.
Each rat continued to favor the type of marking behavior they demonstrated in the control sessions. Preliminary t-tests of the results indicate significant differences between marking during control conditions and marking during burrow conditions; the presence of the burrow seems to cause higher instances of each type marking behavior. Means and p-values will be reported after further analysis.
Our next step will most likely be to begin the male or female rat urine condition. We are continuing to consider how to introduce the urine scent and how much to use in each session. Morning and evening trials will begin during the upcoming weekend.
Here is an example of Flank marking behavior. In the video you can see that Suzi rubs her side up against the walls of the tank. Though it’s brief, it gives a good idea of the behavior we are looking for.
*this video was taken during one of the baseline trials
We ran 2 baseline trials for each of the four rats for a total of 8 trials. Each trial consisted of a 10 minute interval in which all specified marking behaviors were noted. Here is a graph of the averages for each type of marking across the two sessions per rat.
This week, my partner and I have started to observe marking behaviors in our four rats: Lemi, Bianca, Rosie, and Suzi. After conducting a pilot test of our method, we decided to include the observation of vaginal marking behaviors in our study so as to increase the possible number of data points for the experiment and to gain a more complete view of marking behavior. Operationalized definitions of each marking variety can be found in our revised method section.
Having improved our method, Jessica and I began to record marking behaviors in the control condition. I observed all four rats in morning sessions at 8:30 a.m. while Jessica observed the rats during evening sessions later in the day. Each rat exhibited marking behaviors on numerous occassions during their 10 minute trial period in the observation tank. Upon preliminary analysis, there seems to be significant variation between the marking behaviors of each rat. For example, Lemi regularly exhibits flank marking while Bianca regularly exhibits vaginal marking and has yet to demonstrate flank marking behavior. Rosie demonstrates a different preference as she frecuently urine marks in the tank during the trials. This initial observation may lead us to examine individual differences between rats when running statistical analyses at the end of the semester.
Over the next week and a half, we hope to begin observing the rats in the different experimental conditions. To prepare for these sessions, we will order the necesary quantity of male and female rat urine, construct a wire-mesh partition, and design a cardboard burrow. Video updates of our progress will soon be available.
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