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...
Causes of heart palpitations. Heart palpitations are frequently caused by stress or anxiety. In addition to making you feel terrible emotionally, stress can have a physical effect on your body. As a result, stress can cause the nerve endings that control your heart to fire more frequently or irregularly.