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...
Heart Palpitations. Palpitations are feelings that your heart is skipping a beat, fluttering, pounding, or beating too hard or too fast. You may feel palpitations in your chest, throat, or neck during activity or when you are sitting still or lying down. Strong emotions, physical activity, some medicines, caffeine, alcohol, nicotine, or illegal drugs may cause palpitations.