An Uncommon But Regular Visitor

Since we moved to our house in 1998 I have kept feeders in the yard to attract a variety of bird species.  As my yard list has steadily grown over the years and now and again I am able to add one more, there are a few visitors who return each year that I am particularly fond of.  One of these is the White-throated Sparrow.  Each fall as the temperatures begin to fall and I start to fill the seed feeders I wait for the arrival of this uncommon but regular winter visitor. There have only been two winters since 1999 that I have not had one spend the winter in the vicinity of our yard.  This year I am lucky enough to have two of them.  They arrive from somewhere north and east of us joining the White-crowned and Golden-crowned Sparrows to compete for the plentiful free food at my avian diner.  I begin to look for them at Halloween and expect them to leave again by April, they are my winter residents and welcome.  I don't know the life expectancy of these sparrows but I can't imagine that either of the two I have now is my original visitor from 1999 and this makes me wonder.  Are they off-spring?  If so, how is it that they find my yard every year?  While the local Christmas bird counts turn up a number of these birds they are by no means common in these parts. Some of the field guides even say they are rare in our area which is well south and west of their breeding range.  This leads me to believe that the White-throats who inhabit my yard each winter must be passing  the news of good and plentiful food with only occasional fat cats and Sharp-shinned Hawk interruptions along to their chicks and that these birds all come from the same original visitor.  How this is done is not known to me but perhaps those members of the professional wing (pardon the pun) of the brethren would have more to say about that, and perhaps I need to do more reading.  In any case I enjoy their presence, I look for them every morning, seeing  them always brings a smile.  I will send them on their way in the spring with an invitation to return again in the fall and if they themselves can't make it back then I hope they have told the next generation about our yard.