 Extending Families It’s mid-summer and most birds have acquired new rhythms. Gone are the days of frenetic singing, mate luring, and establishing a nest site. Days have become a little less hectic, and food is a little more plentiful. Adult birds wander their territories tending fully grown young. The young learn where the threats are found, and where the food is found. During the past week I’ve watched a nest of Bald Eagles. The once secret aerie life of the parent Eagles is now more of a public affair while the young learn their lessons. Accomplished flight is one of the first out-of-nest challenges for birds. The smaller birds don’t appear to invest much time in flight training before they go over the top. Perhaps their inconspicuous size is an asset, so a crash landing in the surrounding shrubbery is a survival strategy. In the shrubbery the adult birds can find and feed the offspring well enough so the young bird continues developing safely away from conspicuous nest activity. For a nestling Eagle a crash landing could be fatal, so a first flight must be successful and this requires hours of wing practice. When the eaglet is large enough to obtain a good grip it moves away from the nest platform onto supporting tree limbs (if available.) This strategy helps to intercept adult Eagles returning with food and provides some wing room. Now, between food deliveries, the Eaglets exercise their substantial wings until they become quite daring and strong. As they exercise they stand on their tiptoes with talons barely hooking the supporting limb. In essence the Eaglet is flying - just not making forward progress. Flight day does finally arrive and of the nest I watched, things appeared to go very well. The first sign of success came while I was in the pasture sipping my morning coffee. I scanned the surrounding side-hill area and spotted a bulky bird perched on the upper limbs of a dead fir tree. It was a juvenile Bald Eagle. Later that same day I looked at the eagle nest and saw that one of the fledglings had not yet made its own giant step. It remained huddled on one of the limbs near the nest. Later in the day the smug new flier returned to the nest and appeared to gloat. By way of demonstration, or just to show how easy it was, the new flyer perched near the tip of a long branch and flapped its wings rhythmically until losing its grip. Instead of falling, however, it jerkily, but effectively executed a tight circle in the air aided by a steady breeze. It broadened the circle into a wider gyre then swept right past the face of one of the adult birds perched in a nearby tree. Perhaps on the way by it exclaimed “Look Ma, no feet!” It was already so adept that it continued circling, eventually soaring over the pasture and including me in the diameter of the swirling circles. The other fledgling eventually took flight and soon both nestlings took to perching in a tree taller than their nest tree. This tree also happens to hold an old Eagle nest but now that they could fly neither young Eagle ventured near the nursery platform. Over the next few days the adult and juvenile Eagles conducted strange sorties over the west pasture practicing the finer points of hunting. The prey was Columbian ground squirrels. Before the young birds flew, gunshots often rang out over pastures far to the west of the house. The adult Eagles came to know the sound as a dinner bell of sorts and about an hour after the shooting died down, an adult Eagle would usually sail over the house traveling westward. The adult eagle generally reappeared within minutes with a dead ground squirrel clutched in its talons and flew straight toward the nest. But when the young began flying the situation changed. About the time I imagined a fledgling Eagle tucking into a meal of ground squirrel, one of the fledglings sailed from behind some trees. Whether this was a gesture of independence, or a demonstration of impatience, it was obvious this youngster wanted to capture its own prey. The eaglet flew into the west field behind a screen of trees and suddenly appeared on the pasture grass as big and obvious as a mottled garbage can. The ground squirrels, which seem to possess an uncanny ability to assess each predator’s weaknesses and strengths, sat nearby chuckling with obvious glee. It wasn’t bad for a first try but there was much to be learned if ground squirrel was to become regular fare. Even a capable adult Red-tailed Hawk, a bird that routinely hunts the furry field creatures has honed its skills to a precise point to make kills. I have watched a Red-tailed Hawk high in the clear blue sky; fold up like a dark fist and fall with a totally un-birdlike profile, then come skimming across the undulating meadow landscape like a tomahawk missile. Even with all this stealth, a kill is not guaranteed. The young Eagle was not nearly so stealthy; it landed and then proceeded to chase the Ground Squirrels around on foot. Finally the eagle raised its wings and jumped aloft, circling over the now wary crouching squirrels. Perhaps it had time this summer to learn what its wily parent’s knew - that some gunshots mean the table is set. Unfortunately it might also learn that some gunshots meant something entirely different. Luckily, for all the young Eagles and all the other fledglings, there is a lot of summer left; days to spend in the company of those with much to teach. Traveling in the company of doting parents, nestlings are introduced to the wide and warm world of summer, a time of plenty, a time more forgiving than most other seasons of the year. And ample time to secure the next generation. To e-mail Tom CLICK HERE To look at previous column CLICK HERE |
