Migrants Seen From Our Deck

     I have watched the September migrations of birds and insects from many places in Lancaster County, Pennsylvania, including on ridge tops and in farmland.  And on September 20, a few days ago, I saw migrations of birds and insects from our deck in a suburban area of New Holland, Pennsylvania.  I started at 12 noon that day when I spotted an osprey and a broad-winged hawk soaring southwest over our house.
     The sky was partly clear that day, with temperatures in the high seventies and the wind blowing from the south.  Hawks and eagles generally follow the southwest running Appalachian Mountains on strong north and northwest winds.  Those winds push up the northern slopes, forcing the raptors up as they sail along the ridges for miles with scarcely a wing-beat, which conserves their energy.  But on south and southwest winds, the raptors scatter in a southwesterly direction over farmland, suburbs and cities, as those birds continue on to their wintering territories.
     Hawks and eagles that migrate over farmland and cities rely on thermals to give them lift for easy soaring for miles and miles.  Thermals are rising columns of warm air, heated by sunlight shining on the soil of fields and the concrete and asphalt of cities.  As the warmed air rises, it pushes the raptors up with it.  
     While watching the sky from our deck, I saw about eight chimney swifts careening swiftly across the sky after flying insects to eat.  Probably birds that hatched here in New Holland, these swifts will soon join others of their kind in flocks to drift south to northern South America to consume insects while waiting out the northern winter.
     I saw an occasional monarch butterfly flutter over our neighborhood.  Presumably, some were going to Florida to spend the winter, while others were traveling to certain wooded mountains in Mexico.  But each one was migrating to the place where its wintering great-grandparents came from in March of this year.  Miracle of miracles, they find their way without being in those wintering places before.  
     At different times, I saw two groups of broad-winged hawks, named for their wide wings, swirling fairly low over our neighborhood, one flock had eight hawks in it, while the other had seven broadies and two bald eagles, one of the eagles being an immature bird.  As I watched, each gathering of raptors suddenly stopped whirling and peeled off in a line toward the southwest.  What a thrill to see two bald eagles over our house at one time!
     About 3:00 pm, I saw a flock of about 24 broad-winged hawks swirling together before a white cloud high over our property.  I would not have seen those hawks without that cloud formation in their background.  And, as always, the broadies soared out of their circle and sailed swiftly away in a line to the southwest.             
     I have always enjoyed puffy, white or gray cumulus clouds, the kind we can imagine looking like most any objects on Earth, including human faces.  But now these floating pillows in the sky help me see, and identify high-flying birds by their silhouettes and styles of flying or soaring.
     Late in the afternoon I saw two flocks of blue jays migrating low through our neighborhood.  Each bird flapped in the way of its species, which helped identify it.  One group had about 20 individuals, while the other had seven.  These jays could have been from farther north in the United States or southern Canada, places where they raised young.  Both those northern areas can have harsh winters.
     While watching the sky for migrants, I also saw some what I thought were local birds; non-migrants.  A red-tailed hawk flew low over our neighborhood, probably searching for gray squirrels.  I saw a Cooper's hawk dashing over our lawn in its quest for mourning doves and house sparrows to catch and eat.  And I saw a few turkey vultures soaring majestically over our home.  
     I checked the September 20 statistics of Hawk Mountain Sanctuary on the Blue Ridge Mountains of Pennsylvania.  Observers there saw few migrating raptors that day because of the south winds, but tallied many monarchs and blue jays, as I did at home. 
     Migrant raptors in autumn can be spotted almost anywhere in southeastern Pennsylvania, as elsewhere, when winds blow from the south or southwest.  One can even see migrating hawks and eagles at home on those winds, if one watches for those birds high in the sky.