Measuring resting heart rates in penguins using an artificial egg

We report on the use of artificial eggs, fitted with highly sensitive micro phones to record the resting heart rates of Adi lie Penguins (Pygoscelis ad eliae). Artificial eggs were developed to quantify the effects of recording heart rate in penguins using electrocardiogram (ECG) units attached extern ally to the penguins. We found the resting heart rates of penguins recorded using artificial eggs were indistinguishable from those recorded using ECG units. Artificial eggs are a useful tool for quantifying the effects of ot her, more invasive techniques such as attaching ECG units. Artificial eggs are also potentially useful in physiology and energetics studies because th ey are simple to use, are relatively inexpensive to construct and operate, and are comparatively non-invasive to the birds. Nevertheless, some limitat ions of the operation and application of artificial eggs are discussed.