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...
Palpitations of the heart. Palpitations are a sensation or awareness of your heart beating. They may feel like your heart is racing, thumping or skipping beats. Almost everyone has had palpitations at some time in their life. They are usually associated with an abnormal heart rhythm (arrhythmia). Palpitations may have no obvious cause, but can be triggered by: physical activity; emotional stress; caffeine; nicotine. An occasional palpitation that does not affect your general health is not usually something to worry about.