NOTES ON HOLE SIZE: 1  per Bergmann's rule, some species of birds may be larger in colder climates-e.g., a Canadian starling may be bigger than a Florida starling, thus the Canadian bird might not be able to fit in a certain hole size that its southern version could squeeze into.
A heart palpitation is the sensation that your heart has skipped a beat or added an extra beat. It may feel like your heart is racing, pounding, or fluttering. You may become overly aware of your heartbeat. This sensation can also be felt in the...
Palpitation Causes. The heart needs its normal environment to work well. This is especially true for the heart's electrical system; changes in electrical conduction may lead to a decreased ability for the heart to pump blood. From within the body, abnormal levels of electrolytes like potassium, magnesium, and calcium can cause palpitations.