SOUTH-BOUND BANK AND TREE SWALLOWS

     While watching wildlife at Lake Onalaska through a live camera and our computer screen, I noticed mixed flocks of bank swallows and tree swallows perched on the twigs of trees on an alluvial island in the lake.  They were all post-breeding birds gathering together early in August, prior to their migrations south ahead of the coming winter.  And because these swallow species are attracted to larger bodies of fresh water to catch and eat flying insects, the swallows' coming together at Lake Onalaska before drifting south is natural and inevitable.  

     The swallows were all aflutter on their roost between feeding forays after flying insects.  Those birds preened their feathers, socialized and rested and digested while on those trees.

     Lake Onalaska is a large backwater off the Mississippi River in Wisconsin.  It is a good wildlife habitat the year around, but especially in summer.

     That congregation of bank swallows and tree swallows, resting in trees with their youngsters at Onalaska, had raised those young ones earlier that summer.  When I saw them, they were resting from migrating and catching flying insects in mid-air to bolster their fat reserves and stamina for the almost daily flight south to where flying insects are available when winter prevails in the north.  Every day they must alternate drifting farther south, ingesting flying insects, and resting, as they were at Lake Onalaska.  They are always busy.

     Each petite bank swallow is brown on top, white below and has a brown band across its chest.  Each beautiful tree swallow is, more or less, metallic-blue on top and white below.      

     Both these kinds of swallows rear offspring near larger bodies of water across much of North America.  But they do so in different niches.  The swallows find flying insects in abundance around water in summer.  One might think these swallow species would compete for food when raising chicks, and they do a bit.  But bank swallows nest in widely scattered colonies in banks of soil or sand while tree swallows hatch young singly in tree cavities and bird boxes.  Nest sites determine whether these swallow species compete for food or not.

     Each pair of bank swallows uses its tiny nails and beaks to dig out a shaft about two to three feet deep into a soil or sand bank along a waterway or road.  Many banks have scores of bank swallow tunnels in them.  And each pair creates a nursery of dried grass at the end of that burrow.

     The graceful, swift, swooping flight of scores of swallows chasing flying insects is amazing, and entertaining.  They speed and weave among each other, with never a collision.  And all the while in August and September, they drift south to warmer climes where flying insects are available while winter prevails in the north.    

     All swallows are attractive, and elegant masters of flight.  And they are entertaining in the air at all times.  

Comments

Post a Comment

Popular posts from this blog

SPRING ON THE UPPER CHESAPEAKE

      I visited the Upper Chesapeake Bay at the Community Park of Northeast, Maryland one afternoon about the middle of March a few years ago, as I had several times in different seasons before that day.  This time, I went there to spot migrating water birds of various kinds.        Because of their high numbers, gulls and ducks were the dominant birds on the ice, and strips of open water among the slabs of ice because of the warming weather in March.  Most of the handsome ring-billed, herring and great black-backed gulls stood picturesquely on slabs of ice.        The attractive, adult ring-billed and herring gulls are mostly gray on top, white below, and look much alike, except the herrings are larger and have a red mark on their beaks, whereas each ring-bill has a black "ring" around its bill.  Largest of these gulls, the stately, mature black-backs have black backs and upper wings and are white below, making a striking, attractive plumage pattern.        All three of thos
Read more

DADDY-LONG-LEGS

     During summer, over the years in southeastern Pennsylvania, I've seen many daddy-long-legs on the bark of tree trunks on lawns, and in parks and woods.  They blend into the color of tree bark well and are difficult to see.  Many people never see them at all until those camouflaged little critters are pointed out by people in the know about them.        Daddy-long-legs have eight, really long, thin legs, but they are not spiders.  But they are arachnids, and related to spiders.  These attractive, little creatures, called daddy-long-legs because of their long legs, have quarter-inch, compact bodies raised on stilt-like legs.  They have two dark eyes and feel the vibrations of birds and other predators with their legs.  But these arachnids have no venom, or silk to make webs.        Daddy-long-legs, like all other living beings, are part of several food chains.  They consume tiny invertebrates and decaying plant and animal materials they find on tree bark.  And, in turn, many of
Read more

FATHER FINCHES FEEDING FLEDGINGS

     While sitting on our back deck to enjoy the lovely scenery and weather during the afternoon of July 21, 2023, I noticed a tiny, red speck in our tall Norway spruce tree on our suburban lawn in southeastern Pennsylvania.  Peering at that red spot with 16 power binoculars, I saw it was a beautiful male house finch feeding three fledgling house finches; his offspring.  Those gray and dark-streaked young birds fluttered their wings vigorously while being fed invertebrates and seeds.  And the wild charm of those birds was decidedly enhanced by the deep-green of the needled spruce boughs.        Those four house finches were a lovely, exciting sight to me.  I know that species of small birds raises young in our neighborhood every summer, including a pair of house finches that hatch offspring on a support under an awning over our deck.  But never before had I watched a father house finch feed his young outside their twig and grass cradle.  And when that male finch flew off the spruce lim
Read more