One of my editors asked if I might write about nocturnal birdsong. She recounted her recent experience:
“Very early Easter Sunday morning I couldn’t sleep. I was just too sad and worried about the state of things . . . so I got up and made my usual cup of coffee at 4 a.m. It wasn’t very cold so I decided to sit on my back porch and [was] absolutely struck by just how many birds seemed to be singing in the middle of the night! There wasn’t any light at all in the eastern sky—not a smidge—but all kinds of birds were chattering and singing and they were a comfort to me, keeping me company there as I sat alone waiting for the sunrise with the resurrection in mind.”
Many daytime birds produce night music, especially in spring and early summer. During my Army boot camp days at Fort Campbell, Kentucky, a mockingbird sang each night from a red cedar tree next to the barracks. Very few of us appreciated him at the time. Since then I’ve read that most mockingbirds that habitually sing at night have either recently lost their mates or are young, unattached males born the previous year. So that single mockingbird was probably pouring out his heart in vain to a night-time barracks full of other young males who were missing absent wives or girlfriends.
In spring and early summer, as daytime sounds quiet down, most people enjoy hearing an occasional bird sing out in the darkness. At that hour, birdsong can be mysterious or even mesmerizing. One of my favorite singers, the field sparrow, sometimes sings in the middle of the night from our upper pasture. Its simple song is a series of clear, ascending whistles, building into a crescendo trill. To me it recalls childhood days and is one of the loveliest sounds of nature. At night it sounds dreamy, almost spiritual.
Recent studies of bird song reveal that a field sparrow has more worldly reasons to sing at night. The bird I hear may be claiming not just one but several females nesting nearby, announcing to them all that this is his territory. However, recent DNA tests also reveal that many field sparrow nests contain eggs sired by several different males. Is my night singer the king of the meadow reassuring his harem, or is it a rival suitor announcing, “I’m out here too, sweetie, in case you’re interested.”
Nesting season is hard for birds and many attempts fail. Predators, bad weather and accidents take their toll. Ground nesting birds like field sparrows face even greater earthbound dangers. Hayfields are mowed periodically during peak nesting season. A grazing animal might accidently tread upon fragile eggs, young, or sleeping adults. If such incidents happen late in the season there may not be time to re-nest.
But nature provides a backup plan. Should the resident male fall to disaster, another male is there to step into the breach. And if an entire family is destroyed by a hay mower, another female might be raising that male’s progeny. So, in order to put this plan into effect, birds must work overtime, hence the nocturnal singing.
Night-time birdsongs may console, disturb, inspire, or entertain us. But to the birds, it’s serious business.