The wonders of hummingbirds

When the days were long and the dusk ever-lasting, my woodlot rang loud with a deafening chorus of bird song. High in the canopy a red-eyed vireo sang incessantly, while dozens of neotropical migrants gleaned the foliage for insects. They held my wonder, but now that they are departing, it seems the tiny hummingbird will be missed the most.

I remember when I saw my first hummingbird of the season. It was a cloudy cool day in May, but eventually long shafts of light reached through the overcast illuminating my yard. Eager to feel the warm spring sun, I pushed the slider aside and stepped out onto my deck and into the light. The air was sweet, smelled of newly unfolded ferns, and the freshness of a recent rain shower. Suddenly, a hummingbird appeared through the pastel of emerging leaves and made its way to the deck.

It hovered in front of me for a few long moments, as if to determine whether I was a threat or not, and then proceeded to the nectar feeder. It was a male, and its iridescent ruby-colored throat glistened in the morning light. I was so close to it I could hear the hum and feel the rush of air from its wings.

That hummingbird was soon joined by many more in the days to follow. They were everywhere, in the garden, feeding on the deck, and storming me all around the yard. A healthy grove of bee balm, followed by some blooms of foxglove and butterfly bush might explain why. Having so many hummingbirds around allowed for some unusual observations.

Perhaps one of the more astonishing sights was seeing a hummingbird snatch an insect in flight with its long, specialized tongue. On another day, I witnessed a male repeatedly perform a courtship flight in the shape of a U. I hope to find its stucco nest on a branch after the leaves fall.

In September, I began to take special care keeping the nectar feeder full to help them prepare for migration — although the truth, I have learned, is that these tiny birds can’t fuel up for migration until immediately before departing. In fact, their calorie needs are so high that whatever fat they have stored is usually consumed

or spent before the next morning.

Their metabolism changes, however, as they sense the light intensity fade, urging them to migrate. They begin to store fat, and, in the final days before departing, hummingbirds pack weight on quickly. They go from an average of 3.0 grams to roughly 4.5 grams at a rate from 1 to 13 percent of their body weight gained each day. They appear rotund in just a few days, indicating their readiness to depart for the long journey. The excess fat or energy reserves will be needed to maintain the flight speeds that average between 25 to 50 miles per hour.

All of this is fascinating to me. I thought about these things as I watched them buzz about this summer, and now that they are departing, they will be missed. They will have a long and perilous journey to their wintering sites in Central America, but nature will ensure most survive to again return next spring. Imagine, this tiny bird, weighing no more than the nickel in your pocket, flying nonstop 600 miles across the Gulf of Mexico.