Wednesday, February 06, 2013
The earliest birds
The Carolina wren first sang at 6:14 a.m. this morning. I checked to be sure of the time. At that hour no hint of dawn yet colors the eastern horizon. With the snow cover, even just the dusting, the forest is not dark at night. The white snow brightens the woods all night long, making a headlamp largely unnecessary at any hour. In other words, 6:14 a.m. is no lighter or darker than 2 a.m., and in fact, if the wren sings at 6:14, it might just as well sing at 2 a.m.
Still, despite the lack of visual cues, 6:14 a.m. was the first time this wren decided it was morning and proceeded to sing. I used to think northern cardinals were the earliest morning singers in winter, but the Carolina wren has altered that view. It makes me wonder, though, just how a wren knows it is morning when actual daylight is still a good hour off, and the hour it chooses to begin to sing looks the same as 2 a.m.
Doodle, my rooster, for example, doesn’t crow until there’s the barest hint of morning color in the sky. Unless, that is, I turn on my bedroom light in the middle of the night. Then he seems to think morning has come, and I’m likely to hear him crow a few times before I turn my light off again.
Birds are supposed to be sensitive to the so-called false dawn that is not visible to human eyes. False dawn begins about an hour before the actual sunrise. All I can say is that if the Carolina wren is sensing a false dawn, it is remarkably sensitive. This morning the sky was overcast and even foggy, so even the faint false dawn was shrouded by that. Still, the wren sang heartily, as it does every morning. Perhaps it is just hungry, its stomach telling it that food is needed. Mine does the same thing, sometimes.