Wednesday, September 8, 2010

Hummers

     Mention "hummers" in the Research Triangle region of North Carolina, and most will conjure images of the maligned sports utility vehicle.  To birders,  however, "hummers" refer to the most remarkable of all bird groupings, the hummingbirds of the family Trochilidae.  In our region, we have but one species that is a true seasonal resident, the Ruby-throated Hummingbird.
     On a November trip to Costa Rica in 2007, I was delighted to see several species of wintering hummingbird, but I was most dazzled by our very own Ruby-throat, which winters in Central America and breeds in the eastern US.  It astonished me that these tiny birds, not much bigger than bumblebees, could migrate such long distances.  Even more remarkably, many of those Ruby-throats had made their migratory journeys over the open waters of the Gulf of Mexico!  The following spring, back home in Fearrington Village, I had developed an extra appreciation for these miraculous little creatures that suddenly appeared in April and May.
     In order to fuel up for spring and fall migration, Ruby-throats get busy by drinking lots of nectar.  Humans assist this process by placing outdoor feeders, typically filled with sugar water.  Around here, the feeders are mostly quiet during the summer, as Ruby-throats breed and gather nectar from flowering plants like Virginia Creeper.  But come late August and early September, as migration nears, feeders can be swarming with hummers, especially with juvenile birds just learning to fend for themselves.  Prime feeding spots, like outdoor feeders, can bring out fierce territorial behavior in these birds.
    Typically, one Ruby-throat asserts its dominance at a certain feeder, and spends much of the day chasing off other birds.  The defense of these feeding spots can be quite vicious, as many a gardener preparing his fall garden can confirm.  The reward for all this arial jousting is sugar, the ingredient that fuels the hummingbird's voracious metabolic engine.
     In a few weeks, most of the hummers will be gone from this area of the Piedmont, as they head back to Central America for the winter.  Successful birds will survive to attempt next year's spring migration, all for the chance to pass on genes to the next generation.  In the meantime, I will be appreciating these little gems at my feeder, wondering where "my" birds will end up come November.