For the Birds Radio Program: Valentine's Day
Laura talks about two species celebrating the lengthening days with different kinds of courtship.
Transcript
Valentine’s Day birds
Valentine’s Day is a time when many Americans focus on romantic love, when we hear frequent mention of “the birds and the bees,” even though bees and most songbirds are months away from engaging in courtship behaviors. For flying creatures, sex organs are heavy excess baggage. So in most birds they atrophy after the breeding season. Lengthening daylight hours make avian hormone levels surge, leading to courtship behaviors that also induce hormone production. The combination of day length and courting behaviors works together in many species to make the birds physically and physiologically ready to mate and produce young.
Here in northern Minnesota, where I live, the increase in bird songs and woodpecker tappings we’re hearing now is a result of that surge of hormonal levels that will slowly prepare birds for mating. People up here have been telling me how much they’re noticing Black-capped Chickadees singing away, their clear, whistled Hey, sweetie! song warming up even the most frigid February mornings. Chickadees are the original Norwegian bachelor farmers. It takes a lot of singing and increasing day length to get their hormones pumped up enough that each male can overcome his inhibitions to get close enough to one female chickadee to do what birds and bees and educated fleas must do at least once a year.
Like true Minnesotan homesteaders, chickadees focus on the practical matter of excavating a cavity and nest building, rather than more frivolous courtship activities. No chickadee in his right mind would even consider performing some silly romantic dance to attract a mate. No, they limit their romantic gestures to that simple, forthright little Hey, sweetie! song, as the hardworking Pa Ingalls of the Little House books expressed his romantic nature with his fiddle. And even though their singing is on the rise right now, Black-capped Chickadees won’t settle in and consummate their little pairings until April or even May.
One bird species does reach the height of courtship right around Valentine’s Day, in the northern parts of its range. where frigid conditions are keeping other birds more focused on simple survival. Great Horned Owls usually mate for life, and established pairs hang out in the same general territory throughout the winter. They need a lot of space for hunting, so pairs don’t spend much or any time together during late fall and winter, but do maintain contact via occasional hoots. But these hoots turn into full-scale duets accompanied by bowing and tail-bobbing, bill rubbing, and preening one another—romantic gestures no practical chickadee could imagine doing. Unlike chickadees, Great Horned Owls aren’t much into carpentry or home building projects. Up here they usually take over a large stick nest built by other birds such as Red-tailed Hawks. Owls regurgitate a pellet of felted fur and bones about once a day. This is entirely different from their droppings. They often allow these pellets, and feathers of avian prey, to accumulate on and soften the nest floor. They may make other minor modifications to a nest, but most Great Horned Owl pairs would never attempt even the easiest home improvement projects.
Great Horned Owls start producing eggs as early as late November in Florida, but in the more frigid reaches of their range, they hold off until mid-winter. In Alberta, they may produce their first eggs in late January. In Michigan, first eggs are laid beginning around Valentine’s Day. So this is the right time to get out at night listening for them. To our ears, their hoots can sound eerie or thrilling. To them, they’re romantic expressions of lasting commitment.