Above: Dani Douglas presenting on her research on measuring heart rates of brown anole eggs at the annual Society for Integrative and Comparative Biology Meeting in New Orleans, Louisiana.
Heart rate can tell us a lot about how an animal’s physiology is influenced by environmental conditions. Even embryos can provide valuable heart rate information. Scientists have used the Buddy® system, a digital egg heart rate monitor, to measure heart rate in large eggs, such as those from chickens or iguanas. But can the Buddy® system detect heart rate measurements from much smaller eggs?
Dani Douglas, an undergraduate student at Auburn University, took heart rate measurements from brown anole (Anolis sagrei) eggs using the Buddy® system.
Compared to a chicken egg, a brown anole egg is tiny – smaller than a quarter. Douglas kept the anole eggs in an incubator that varied temperature over the course of each day. At different points during the day, Douglas removed eggs from the incubator to measure heart rate with the Buddy®.
Douglas was elated to find that the Buddy® system could reliably measure heart rate in those small anole eggs. This finding is especially exciting because the Buddy® system is non-invasive, so scientists can measure heart rate over the development of the eggs.
Douglas also found that anole egg heart rates were positively correlated with temperature fluctuation. Anole egg heart rate was not related to the age of the egg.
All research comes with its own set of challenges. When each anole egg is removed from the incubator, its temperature begins to go down immediately. Douglas needed to measure heart rate quickly to avoid confounding effects of cooling, which can be tricky.
Challenges aside, it is promising that Douglas and her colleagues have confirmed that heart rate can be measured in tiny anole eggs.