La première expérience est terminée (The first experiment is finished)

Our first experiment is completed! Well, almost…

This week we have finished up the last measurements of performance, metabolic rates, and the collection of blood samples for this first experiment. I’m glad to say that Mahaut, Jérémie, Hugo, Elodie, and I – along with Becky and the kids – were able to celebrate with a beer yesterday afternoon at the new (and only!) restaurant inMoulis. We had a well-deserved toast to all the hard work everyone has put in to this experiment over the past three months. And of course, with regrets that Antonio and Fabien were not here to raise a glass with us as well.

Yet of course, the end of the experiment certainly is not the end of the work. Mahaut is diligently working to score the videorecordings of lizards sprinting…with 86 lizards each sprinting 12 times across three timepoints, that’s over 3000 data points! We're using the program Solomon Coder, free software that works great for scoring behaviour or performance from videorecordings. 

Screen shot from the Solomon Coder software. Mahaut is currently using this software to extract the sprint speed from all of our videorecordings.

I’m working to extract the metabolic rate data from the raw traces using ExpeData software from Sable Systems, the company that makes the respirometry equipment we're using (FOXBOX Field Gas Analysis System). I am extracting the maximum level of carbon dioxide production by lizards after they are run to exhaustion as an indicator of their maximum metabolic rate.

Screen shot of ExpeData software used to extract data on oxygen consumption and carbon dioxide production. Traces from four individuals are shown here. Notice the peak carbon dioxide production that occurs after about five minutes followed by a gradual decreasing to resting levels.

Along with data on hematocrit and red blood cell counts, we’ll soon share results of how the low-oxygen environment of high altitudes impacts lizard physiology and performance in our talk at the upcoming Colloque d'Écophysiologie Animale in Strasbourg the first week of November. I’ll be giving a talk titled: “Lizards on the peak: Hypoxia induces physiological responses and bears performance consequences in Common Wall Lizards transplanted to high elevations.”

Freshly-spun capillary tubes, each containing about 15 μL of whole blood. Centrifugation separates the red blood cells from the plasma. We can then measure haematocrit, the ratio of packed red blood cells to total blood volume.

After that…there’s still much more work to be done, including measuring haemoglobin concentrations from the blood samples as well as developing protocols to measure hormones related to metabolic regulation, such as triiodothyronine (T3). But of course, just because there’s plenty more work to do doesn’t mean we shouldn’t pause to have a well-deserved celebration over a beer!