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 can also result from a range of heart arrhythmias. These are classified by location, and type of heartbeat. A few common types: 1  Supraventricular tachycardia â A rapid heart rate originating above the ventricles (lower heart chambers). 2  It can cause the heart to beat very quickly or erratically.