Carolina Wrens and Carolina Chickadees

     Carolina wrens and Carolina chickadees are species of small birds that permanently inhabit bottomland woods, and have adapted to older suburban areas with their many tall trees and large bushes, including in my back lawn in New Holland, Pennsylvania.  Both species nest in my neighborhood and I see them year around.  But I am most likely to see them on an almost daily basis in mid-winter when deciduous foliage is down and these birds come to our feeders.  Both species are originally more southern in distribution, as their name implies.  However, severe winters can reduce Carolina wrens numbers here in the north.  But, hopefully, the survivors will have genetic codes that will allow their descendants to better survive northern winters. 
     Both these little birds are attractive, each in its own camouflaged way.  And, although they are not seed eaters, both kinds come to feeders, particularly in winter, to eat sunflower seeds and grain softened by the weather. 
     The wrens are warm-brown on top and a light brown below, allowing them to blend into the soil and dead wood they constantly frequent when looking for invertebrate food on, or near, the ground.  This type of bird is almost always on, or close to, the ground, the place to look for them. 
     Carolina wrens nest in sheltered places, such as wood piles, brush heaps, stone walls and hollow logs on the ground.  They also hatch young in such human-made articles as outdoor grills, under decks, in utility sheds and mail boxes, and other such places.  Male Carolinas have loud, chanting songs that we readily hear throughout the year as they establish and constantly proclaim their nesting territories for themselves and their mates.       
     In winter when snow is on the ground or the soil is frozen, these wrens can be hard pressed to find food.  But they search under thick bushes and fallen logs, in brush and rock piles, and along little seepages where the snow can't reach or melts away, allowing some invertebrates to remain active through much of winter. 
     Carolina chickadees are as gray as the bark of the twigs and trunks of the tops of the bushes and trees they perch on.  They also have black caps and bibs that add color contrast to their plumages.  I particularly like when they hop through the top limbs of our large pussy willow shrub that stands only a few feet from our upstairs bedroom window.  There these pretty and brave little birds are close-up, gray on gray, especially when the sun shines on that tall shrub and when its furry male catkins are in bloom late in February and into early March.
     Because the chickadees are in the tree or bush tops and the Carolina wrens are on the ground for the most part, these two species of birds don't compete directly for invertebrate food.  The chicks eat tiny invertebrates and their eggs from crevices in bark, buds and leaves.  Even at feeders, the wrens get food from the ground while the chicks do so at the feeders themselves off the ground. 
     Early in spring, male chickadees repeatedly sing "chick-a-dee-dee-dee" to establish and maintain nesting territories.  Chickadees hatch young in abandoned woodpecker holes and other cavities in trees.  But they have also adapted to rearing offspring in house wren or bluebird nest boxes erected  in woodland edges and maturing suburban areas.  House sparrows, eastern bluebirds, tree swallows and, especially, house wrens, are some of the competitors for nesting hollows.  House wrens are as small as the chickadees and often throw other birds' eggs out of nests so the house wrens can take over those nurseries for themselves.  But chickadees are small, which eliminates some of the slightly larger birds in rivalry for nesting cavities because they are too big to squeeze into chickadee cavities.
     Watch for these species of small birds on your lawns or in bottomland woods.  They are attractive, and interesting because they get food in different niches of their shared habitats, thus reducing competition between them for that food.