This week, my wife and I experienced mixed emotions as yet another son - our last - left "the nest." In the bird world, this happens millions - perhaps even billions - of times each year. Whether human or bird, parents raises their young in anticipation that their fledglings will leave the nest. For humans, that process is many years in the making. For birds, the period of time for rearing and training can be as short as only a few weeks!

I frequently explain to customers that sometimes baby birds leave the nest before we think they are ready. During breeding season, it is not uncommon to receive phone calls from individuals who have "rescued" a baby bird. Sometimes individuals attempt to put the baby bird back in its nest, only to discover a short time later that the baby is down on the ground again.

In many species, baby birds spend a good portion of their time down on the ground after leaving the nest. While they are capable of flying short distances, their flight feathers and their muscles are not sufficiently developed to allow them to fly like their parents.

Remarkably, in a few short weeks, baby birds become independent - they are capable of foraging for food and are adept at avoiding danger. This period of time between fledging and migration is critical if they are going to survive the rigors of long-distance migration.

While rearing young, parent birds are dedicated and devoted. They work tirelessly to provide food from sun-up to sundown, and they defend the nest site from all kinds of intruders. However, shortly after the juveniles have fledged, that familial bond weakens. The attentiveness and devotion fades and the juveniles very quickly become independent of their parents. Within just a few weeks, the parents go off and do their own thing, leaving the juveniles to fend for themselves.

One aspect of bird migration that absolutely fascinates me is how the parents in many species leave their breeding range several weeks before the juveniles. The juveniles are literally left to find their own way to their winter habitat - someplace where they have never been, traversing a route they have never traveled.

And yet, somehow, the miracle of migration occurs over and over again as juveniles use the same migration route and eventually end up in the same place as their parents. Migration is one of the true wonders of creation. To think a creature weighing mere grams can travel thousands of miles without parental guidance and end up in the right place is astonishing.

And so the cycle of life continues, year after year, with species moving from their summer range to their winter range, and back again, rearing young, providing for the continuation of their species.

Our interactions with nature and our observations of wildlife, particularly birds, provide a lot of parallels for life. We draw upon our own experiences and the experiences we witness in the natural world around us. We see the life and death drama of birds in our yard, we see them rearing their young, we see them coming and going with the seasons, and all of these experiences create a connection between us and nature.

Our lives are certainly enriched by the nature that surrounds us - the singing of wild birds, the joy of seeing a family of baby quail in our yard, the coming and going of hummingbirds as they battle at our feeders, and the goldfinches flocking to our finch feeders.