WOODLAND LEVELS OF WINTERING BIRDS

      Most of the time deciduous woods in southeastern Pennsylvania, in winter, are quiet and seemingly with little life.  But there are many small creatures, including dormant invertebrates and amphibians and reptiles, active mice and shrews, and small, wintering birds in those leafless, gray woods.  Those attractive birds liven winter woods.    

     Those little birds, which are camouflaged and difficult to spot in winter woods, including Carolina chickadees, tufted titmice, golden-crowned kinglets, two kinds of nuthatches, downy woodpeckers, brown creepers, Carolina wrens and winter wrens, are not scattered randomly in the woods.  Each interesting species is tied to its own level, though there is overlap of layers among the birds.  That spreading of those lovely, little birds into different strata in the woods reduces competition for invertebrate food among them.   

     Permanent resident and related Carolina chickadees and tufted titmice, and wintering golden-crowned kinglets all constantly flutter and hover among tree top buds and twigs to seize tiny, dormant invertebrates and their eggs from crevices in those tree parts.  These small birds, when seen, are entertaining to watch.  Chickadees and titmice spend winter nights in tree cavities.

     Permanent resident white-breasted nuthatches and downy woodpeckers and wintering red-breasted nuthatches and brown creepers search for invertebrates and their eggs in crevices in tree bark, mostly in the middle level of a woods.  These intriguing birds hitch up tree after tree, all day, every day, to make their living, but each kind in its own way.  And all these birds spend winter nights in tree hollows.        

     Woodpeckers move up tree trunks by digging their sharp toe nails in the bark and using their stiff tail feathers as braces.  They use their stout beaks to chip under the bark and into dead wood.  Then they run their long, sticky tongues into invertebrate tunnels in the dead wood to extract those small critters with their tongues and swallow those victims.  

     Nuthatches are the only North American birds that can walk down a tree trunk head-first and walk up-side-down on a limb.  All the while they are inspecting cracks in the bark for invertebrates they pry out with their sturdy, sharp bills.  

     Creepers spiral up tree trunks in jerky motions as they watch for invertebrates in bark crevices.  Creepers have long, decurved beaks for probing into cracks after their prey.  At some point in creeping up a large tree, they drop off that tree and flutter down to the base of another big tree, and so on all day.

     Permanent resident and handsome Carolina wrens generally search for invertebrates among vines, shrubs, piles of rocks and brush, tree roots and fallen logs and leaves, near and on woodland floors.  They are warm-brown all over and stick tight to cover, which makes them hard to notice.  These wrens also spend winter nights in any of the above mentioned sheltering feeding places.  

     And wintering winter wrens are dark brown and even tougher to see.  These tiny wrens mostly stick to fallen leaves and logs, tree roots and the edges of tumbling woodland streams where they look for invertebrates, and spend winter nights.        

     All these attractive, interesting little birds make winter woods more lively.  But one sometimes has to look carefully for them in their choice of niches.