Wintering River Ducks and Bay Ducks

     One afternoon in January I saw a pair of greater scaup ducks on the Conestoga River in Lancaster County, Pennsylvania.  I was never so close to this kind of bay duck before, and with 16-power binoculars, I could see their every detail and how beautiful they were.  The drake was light-gray with a green sheen on his head feathers.  The hen was rich-brown all over with much white on her face at the base of her beak.  Both birds repeatedly dove under water and swam to the river bottom to eat aquatic plants, snails and smaller crayfish.
     A few days before seeing the scaup, I noticed a mixed group of ducks in a strip of open water among sheets of ice in the middle of the Susquehanna River near Columbia, Pennsylvania.  Ducks there were common goldeneyes and buffleheads, which are related river species, and greater scaups, lesser scaups and red-headed ducks, which are related bay ducks.  All those river and bay ducks took turns diving to the bottom of the Susquehanna for food. 
     Goldeneyes and buffleheads of the genus Bucephala winter mostly on rivers and back waters off estuaries in eastern North America.  Drakes of these two species have similar black and white patterns on top and green sheens to their heads, showing their relatedness.  Their mates have brown plumages that camouflages them when hatching eggs and rearing ducklings.  Goldeneyes' wings whistle when they are in flight.  And both species swim under water with their feet only.  Both species mostly ingest aquatic insects, snails, crustaceans and small fish.  The bigger, stronger goldeneyes overturn underwater stones to get food.
     Five kinds of bay ducks in the genus Aythya winter in "rafts" of their floating, bobbing bodies, often in the hundreds or thousands, far out on estuaries and the mouths of larger rivers, though they overlap the habitats of river ducks at times.  Most of the time one can only spot and identify these ducks with scopes.  Bay ducks include greater and lesser scaups, ring-necked ducks, which also rest and feed on built impoundments, particularly during their spring migration north and west to breeding grounds, red-headed ducks and canvasback ducks.  Females of each of these species are mostly brown, which allows them to blend into their surroundings and have a better chance of escaping predation.  But their mates are more colorful.  Male lesser scaups and ring-necked ducks have purple iridescence to their heads, while the heads of red-heads and canvasbacks are dull red.  But both genders of canvasbacks have sloping foreheads that set that species apart. 
     Bay ducks dive to the bottoms of large bodies of water to get food, swimming under water with their feet only.  The foods of these related species are aquatic plants and water insects.  Canvasbacks also eat shellfish and small fish.  Those slight variances of food choices educe competition for food among these ducks in the same habitat.       
     River ducks and bay ducks winter way out on large bodies of water where there is no shelter for them, except their own dense feathers.  They spend most of their days rocking on the little wavelets or diving to the bottoms of those bodies of water for food or to escape airborne predation such as from bald eagles.  Watch for these attractive and interesting ducks when along rivers or bays in winter.  

Nature Highlights at Home

    One evening several years ago, four recently fledged screech owls lined up on four posts of our front porch for a short time.  Those young owls were cute and quite a sight while they were there.  Though our lawn and the lawns adjoining ours are not wildlife sanctuaries, they have had their outstanding natural moments of adaptable creatures through the years we've lived in our present home in New Holland, Pennsylvania, making our lives there the more interesting.
     Small birds, particularly house sparrows, have been visiting our bird feeders for the last several winters.  Occasionally we see a Cooper's hawk or a sharp-shinned hawk waiting to ambush a bird, sometimes with success.  I've seen a Cooper's scrambling on foot under bushes after sparrows and another one of those hawks another time dining on a house sparrow, as the little bird's feathers floated to the ground.  And once I saw a sharpy feeding on a house sparrow on top of snow in a snow storm.  The hawk ate all of the bird it could, as feathers drifted across the yard with the snow.  And soon after that raptor finished its meal and flew away to hunt more prey, the few pathetic bones and feathers left behind were quickly buried in falling and drifting snow.
     One March day a few years back, a great blue heron caught and ate all our goldfish from our one-hundred gallon, backyard, goldfish pond.  One day the fish were there, the next they weren't.  I didn't see the tragedy, but a neighbor did and told me about it.  We now have a net over our pond to keep herons and other predators out. 
     A couple of times early in March, migrating American robins have stopped at a neighbor's female American holly tree to eat the red berries still on that tree.  They were an attractive, interesting sight on that tree until all the berries were stripped off and consumed. 
     Every spring for a few years, a pair of mallard ducks visited our goldfish pond.  That happened before we put a net over the pond.  The ducks never ate the fish, but they seemed to have a good time splashing in our pond. 
     One spring a mallard hen laid a clutch of 12 eggs under a bush in our yard.  I knew the day she laid the last egg and marked the day they would hatch: It takes 28 days of incubation until ducklings hatch.  Sure enough, on the morning they were to hatch, the hen was looking around cautiously, I guess to see if their was no danger nearby.  Suddenly she left her nest behind, trailed by a dozen newly-hatched, fuzzy ducklings in a line, apparently going to a nearby pond.
     A couple of female cottontail rabbits have dropped litters in flower beds on our lawns.  One rabbit nursery was under the same shrub where the duck cradle was, but in a different year.  Another rabbit nest was in a flower bed against the house.  There may have been other rabbit nurseries that I never saw, or some baby rabbits were caught and eaten by the few house cats we have loose in our neighborhood.  But at any rate, the young rabbits we did see on our lawn were cute.
     One morning in the middle of May, I was walking the dog and saw a mother opossum waddling across the street in front of our house with about six babies on her back.  The dog wanted to attack her, but that didn't happen.  When the female opossum got to our front yard, she slipped under a shrub and disappeared.  Fortunately, she seemed to have gotten away because I didn't see her again.
     Some winter evenings, I see a red-tailed hawk and/or a Cooper's hawk landing to spend the night in one or two of our tall Norway spruce trees in our back yard.  They certainly bring a bit of the wild into our yard when they do that.
     Occasionally at night, particularly in winter, I hear a pair of great horned owls calling to each other in our immediate neighborhood.  They must raise young in a tall evergreen somewhere nearby.  At any rate, their hooting is thrilling to hear.
     Several kinds of birds nest on our lawn, including mourning doves, American robins, song sparrows, northern cardinals, blue jays, gray catbirds, Carolina chickadees, tufted titmice, Carolina wrens and house wrens.  The last four species are originally woodland birds that traditionally rear offspring in tree cavities, abandoned woodpecker holes and bird boxes erected for them, including in our yard.  A couple of times, doves have laid their two white eggs in a clutch in flower pots on our front porch.  And over the years, I have seen parents of all these species feeding their fledged young.
       But the prize for the most unusual nest site in our immediate neighborhood has to go to a pair of Carolina wrens.  They hatch a brood in a neighbor's outdoor cooking grill.  Luckily, the time was in spring before the people intended to use that grill.      
      About six little brown bats seem to drop out of the trees in our area at dusk on warm evenings and zig-zag and swoop over our lawn and surrounding ones to catch insects in mid-air.  They are always entertaining to watch until the twilight fades to darkness.
     One summer we found a bumble bee nest with a few each of worker bees, larvae and honey pots in a field mouse nest under a bench sitting in a flower bed.  We accidentally disturbed it and the bees eventually abandoned it.   
     Another summer we had a yellow jacket nest in our basement.  Of course, nobody liked that.  I suggested leaving them alone because in fall the female workers that sting would all die, and the queen would bury herself in the lawn for the winter to live until next spring when she would start a new colony elsewhere.  And that is what happened.
     There was a loose colony of female cicada killer wasps in a patch of bare soil in the next door neighbors' yard during another summer.  We saw the cicada killers bringing back paralyzed annual cicadas through the air.  Each wasp landed in front of her shallow burrow and dragged the cicada into it.  Then each female wasp would lay an egg on each cicada that the wasp larva would eat until it pupated and changed to an adult wasp.     
     Like most lawns in Lancaster County, ours has a lot of fireflies flashing their cold lights each dusk in July.  Male fireflies crawl up grass stems and take off into the air, flashing their lights all the while.
The males' lights encourage females in the grass to respond with their own dim glows so the males can see them to mate with them. 
     In summer, I find leaves on shrubbery on our lawn with quarter-inch, round holes cut out of them.
That is the work of leaf-cutter bees.  Those bees cut out the leaf parts to line hollow stems where they lay several eggs.  The stems and leaf parts protect the bee larvae as they feed on pellets of pollen and honey, pupate and emerge as adult leaf-cutter bees.
     A couple of summers, I found what appeared to be moth or butterfly caterpillars on our red-twig dogwood bushes.  But I could not identify those larvae until one day, by dumb luck, I saw in an identification book the larvae of a saw-fly wasp.  They were the caterpillars I saw in the dogwoods.  That mystery was solved.   
     Once in a while in September, migrant monarch butterflies pass through our yard as part of their exodus southwest to certain forests on mountains in Mexico to spend the winter.  And a couple of times, several monarchs have spent a September night perched on our Norway spruce trees.  But the next day they were gone, never to return.
     Loose rivers of north-bound red admiral butterflies poured through this county for several days early in May one year, most of them swiftly and low to the ground, creating quite a spectacle that I had never seen before..  Females of that species soon laid eggs on stinging nettle plants which were full of red admiral larvae toward the end of May.
     Some summers I plant parsley plants to attract female black swallowtail butterflies to lay eggs on them, which they usually do.  I then watch their larvae ingesting parsley leaves, grow, pupate and emerge from their chrysalises as beautiful, adult butterflies ready to breed and lay another generation of eggs.
    Most any neighborhood or lawn in the Mid-Atlantic States has an abundance of adaptable wildlife.  We need only look for it, which will make our lives more enjoyable.

Pintails, Gadwalls and Wigeons

     Northern pintails, gadwalls and American wigeons are three types of ducks that have a few traits in common., including being mostly vegetarians and having characteristics unique to themselves.  Drakes of each species are attractive in their own plain ways.  Females of each kind are brown, which camouflages them on nests and while raising young.  Youngsters of these species feed mostly on invertebrates for the protein, but the adults are vegetarians for the most part.  And populations of each of these duck species winter on certain ponds and wetlands here in the Middle Atlantic States.
     Pintail drakes have mostly grayish plumages, with brown heads and necks, white throats and chests and black rears.  These birds also have two long tail feathers that give them their common name.  Both males and females of this species have long, streamlined necks and bodies and are particularly swift flyers.
    Pintails gather in large groups of their own kind on shallow impoundments during winter.  Adults of this species mostly eat seeds during that harshest of seasons.
     Pintails breed around ponds throughout much of the northern hemisphere.  Early in spring, while on migration north, each female takes off in flight, followed by a small group of males.  The male that stays with the female longest in the air gets to be her mate for the season.  Losing males will try to keep up with other females. 
     Pretty little ducks in a plain way, drake gadwalls are mostly gray with pale-brown heads, a white patch on each wing and black rears under their tails.  Females also have white squares on their wings.
     Like pintails, gadwalls breed around ponds through much of the northern hemisphere.  In winter, they come together in small groups on certain ponds they use every year.  Adults consume mostly aquatic plants through the year.
     American wigeons are small, plump ducks.  Drakes are mostly light-brown with white crowns,  an iridescent green stripe through each side of the face, a white patch on each wing and a black rear.  
     Adults of this species ingest a lot of water vegetation, even harassing coots and diving, plant-eating ducks to steal the vegetation they bring to the surface to consume.  But wigeons do "tip-up" to shovel up water plants from the bottoms of shallow water.
     Wigeons also join Canada geese and other kinds of geese in eating grass and the green shoots of winter rye during winter.  One can see the large Canadas and the diminutive wigeons on lawns or in fields together feeding on that green vegetation.            
     These species of ducks are attractive in plain ways and interesting here in winter.  One can see some of these ducks and other kinds wintering in the Mid-Atlantic States by getting out to ponds and wetlands during that season and into early spring when they migrate to their respective breeding grounds.   

Snow and Ice

     Several inches of wet snow often fall on Lancaster County, Pennsylvania.  Limbs and twigs of coniferous and deciduous trees and shrubs get beautifully covered by snow.  And sullen, gray skies, or sunny ones, and snow-covered ground and trees create pretty scenery in gray woods, or suburbs with their green conifers, and beige fields.
     The next day rain might fall, covering every twig of every tree and shrub with a coating of transparent ice.  And ice would be on clumps of snow still plastered to tree limbs.  Those branches get weighed down by the snow and ice on them, some of them to the point of breaking off and falling to the snow-covered ground.  White pine trees are particularly vulnerable to damage from strong wind and the weight of ice and snow. 
     Ice and snow on tree limbs, the ground, red or orange berries and everything else is hard on some kinds of wildlife that can't get to their food sources until that ice and snow melts.  Those species must look for food elsewhere or do without until the ice and snow melts away.
     On rainy days after a snowfall, everything is sheathed in silvery, transparent ice, and translucent, dripping  icicles, creating an uncommon beauty on the landscape.  But it is a fleeting beauty, a kind that we should get out to experience as soon as possible before it is gone in the sunlight and warmth. 
     Fortunately for the trees and bushes, and wildlife, snow and ice melt when temperatures warm and drip, relieving the tree and bush branches of some of the weight on them, allowing them to lift themselves to normal levels above the ground.  An occasional light wind that moves the limbs knocks some of the ice and snow off them, further taking the burden off them.  And as the ice melts away, so does the silvery look of twigs and needles.
     During clear, winter days, low-slanting sunlight enhances the colors of green coniferous tree needles, the gray or brown bark of deciduous trees, the brightly colored berries and the beige of weeds and tall grasses.  Snow outlining each branch and twig on the stately trees make them picturesque before the deep, blue sky.  And ice and icicles on all those natural features sparkle like innumerable diamonds.      
     Sunsets at the ends of sunny, winter days are brilliant and beautiful.  The striking shapes of trees are silhouetted black before those sunsets.  Sometimes one sees the black V's of a group of Canada geese flying before the sunset.  And as the sunset gradually fades, one can see the moon, Venus and stars coming into view in the sky.  Still later, the moon's reflected light on snow on the ground makes the landscape almost as bright as day, but without the colors.  Sometimes at night, white-tailed deer can be seen on the snow cover.  
     Or on overcast nights, the light of outdoor lights bounces off the clouds and the snow on the ground, again making the landscape almost as bright as day.  Again, we can see geese in the sky or deer and rabbits in the snow on the ground. 
     Though snow and ice are dangerous, they still are a part of winter's beauties.  These have been some of the beauties created by them during winter in Lancaster County, as elsewhere.        

Permanent Resident Birds in our Neighborhood

     I've noted ten kinds of adaptable, permanent resident birds living in about six acres of our neighborhood.  Some thicket species, including northern cardinals, song sparrows, Carolina wrens and northern mockingbirds, are here because of shrubbery to shelter in, especially at night.  Woodland species, such as blue jays, Carolina chickadees, tufted titmice, white-breasted nuthatches and downy woodpeckers are here because of larger trees in the neighborhood.  All these species, except the jays, seek cover for protection and nesting in tree hollows.  All these species of small birds are native to the area, except the one hundred or more house sparrows living here because of shrubs, buildings and bird feeders.  House sparrows raise young in crevices in buildings and shelter at night in shrubbery.  And all these species visit bird feeders, including wrens and mockers on occasion. 
     Our neighborhood is not a wildlife sanctuary, but it does have its wildlife that I know intimately on an almost daily basis.  And the birds here are as interesting as those anywhere.  They have been here for years, but mostly as a pair of each kind, except the house sparrow flock.
     Being brown or gray in plumage, most of these birds are difficult to see because they blend into their surroundings.  Exceptions to that are the red male cardinals, and the blue jays.  Camouflage helps protect creatures from predation.
     All these birds have natural foods in our neighborhood, which is why they are here in the first place.  They all eat invertebrates during the warmer months and feed the same food to their young in their nurseries.  Nuthatches get much invertebrate food from crevices in tree bark, while downies chip into dead wood under bark to get that same sustenance.  Mockingbirds ingest berries during winter, while cardinals, song sparrows and house sparrows consume weed and grass seeds.  And blue jays eat pin oak acorns, as well as seeds, berries and whatever invertebrates they find.  Since each kind of bird has its own food choices, competition for food is reduced among the species.     
     Sometimes a Cooper's hawk or free-roaming house cat stalks these birds, particularly at feeders.  The hawks hide in nearby evergreen trees until a bird is vulnerable.  The cats creep along or crouch on the ground, using shrubbery to hide their movements.  The hawks occasionally catch a small bird, but I've never seen a cat get one in our yard, though house cats can be bad news to small wildlife.
     Male northern cardinals, tufted titmice, song sparrows, northern mockingbirds, Carolina wrens and white-breasted nuthatches are notable for singing in local woods and suburbs on warm days in February.  Downy woodpeckers drum on hollow limbs and roofs, which, for them, is equivalent to song.  Longer periods of daylight each succeeding day and warming temperatures stir the birds' hormones and prepare them for breeding and nesting.  People weary of winter are glad to hear those first songs of nature close to home.         
     These permanent resident birds add much beauty and intrigue to lawns here, as other bird species do throughout the world.  Anyone can see wildlife around home: Just watch for it.   

Darters

     Rocky-bottomed brooks and streams in Lancaster County, Pennsylvania, as in much of North America, are inhabited by various kinds of minnows and other types of fresh-water fish.  These fish have air bladders that help them hold positions with ease in the water above the stream bed.  There they feed on invertebrates that float in the water in mid-stream and on the surface. 
     But there is a species of small fish living year around on the stony bottoms of Lancaster County waterways that don't have air bladders and can rise from the bottom only with effort, with quick spurts, hence their common name.  These two-inch fish are called Johnny darters that specialize in getting invertebrate food among the pebbles on stream bottoms, the only kind of fish that does so exclusively.  There they are neighbors to crayfish, freshwater snails and clams, and several kinds of aquatic insect larvae.  In fact, these fish ingest some of the eggs and tiny young of those creatures. 
     Darters are streamlined to cope with strong currents, but generally lodge between pebbles to hide and not be swept away in the current.  Since the darters feed in a niche different from the one minnows get food in, competition for food and space is reduced between these different types of fish.  Therefore, they can all live in the same waterways with plenty of food for all.
     Attractive in their own plain way, darters are brown all over with dark markings, which camouflages them among the stones on the bottoms of the waterways.  Of course, they are almost impossible to see, until they move.  But with a bit of patience and time, one or more of these small, interesting fish can be spotted darting among stones on the bottom of a waterway.  And when one is spotted, more are sure to be seen zipping here and there among the rocks in search of food, or mates.
     Darters spawn their eggs on the gravelly bottoms of waterways.  The youngsters hatch and stay among the stones to search for tiny invertebrates or their eggs to eat.
     Though darters live between rocks on stream bottoms, they still fall prey to various predatory creatures when they are noticed dashing about in search of food.  Some of the predators that eat darters include larger fish, water snakes, belted kingfishers, a small variety of herons, mink and other critters.   
     Darters found a niche for themselves on the gravelly bottoms of running waterways.  There they hide, blending in with the colors of the stones.  But with patience and watching, one can see through their camouflage and spot some of them among the stones on the bottom of those streams. 

My Favorite Ducks

     Black ducks and wood ducks are my favorite ducks in Lancaster County, Pennsylvania.  Blacks are my favored ones in winter and I am most thrilled with woodies in summer.  Coincidentally, both species traditionally nest in forests of eastern North America, black ducks mostly in New England and eastern Canada and wood ducks from New England south to Florida and the Gulf Coast.  Therefore, flocks of black ducks only winter on Lancaster County's impoundments and larger waterways when woodies are absent from this area.  The lake at Middle Creek Wildlife Management Area is one good lake to see numbers of wintering black ducks 
     Both species of these exclusively North American ducks are handsome, each in its own way.  Both genders of black ducks are dark all over to blend into forest shadows, and large and robust to deal with northern winters.  Blacks have a patch of iridescent purple on each upper wing and white underwing feathers that are noticed only when the birds fly.  Black ducks do look black when on ice or snow, or when seen in the distance. 
     Wood ducks are smaller than black ducks, but again both genders of woodies are dark, which camouflages them in woods.  Drake woodies are colorfully plumaged to compete for the favors of females of their kind.  They have a crest on their heads that gleams green in the sunlight and red beaks.  And they have white and iridescent blue stripes and markings on their bodies.  Female woodies are mostly smoky-gray all over with a white ring around each eye.
     Flocks of black ducks are in Lancaster County from around the end of October to the latter part of March.  Along with groups of the closely related mallard ducks, plus Canada geese and maybe a great blue heron or bald eagle or two, black ducks liven many waterways and impoundments in Lancaster County during winter.  The ducks and geese rest on the safety of water, but fly swiftly twice a day, often at dusk for one of those times, to harvested corn fields to feed on kernels of corn still lying in the fields.  When full, those same birds return, group after group, to the water to rest and digest in relative safety.
     Wood ducks arrive here early in March, already paired and ready to raise young.  I enjoy seeing black ducks and wood ducks on the same waters during that month.  Both species, being cautious for self preservation, usually stay under limbs of trees that extend low over the water, another reason
 they developed dark plumages. 
     If one looks, female wood ducks can be spotted searching for unused tree hollows and wood duck nest boxes along waterways and impoundments in woods and strips of trees in farmland to lay their 12 or more eggs.  The females, and the their mates, are small and lithe in the trees, the body build needed for treetop adventures. 
     Nest boxes certainly have increased woodies' nesting success and numbers.  And people could allow more dead trees to stand along water that woodies and other creatures could use as homes and cradles. 
     Hen wood ducks incubate their eggs for four weeks and by mid-May the fuzzy ducklings jump out of their nurseries to water or the ground and are led to water where they can feed on invertebrates.
  Like all young ducks, wood ducks grow up fast and are full-sized by September.  Now they fatten
up and strengthen muscles for their flight south sometime in October.
     Look for black ducks in winter and wood ducks in summer.  They are beautiful wild ducks with interesting life histories, which helps make local waters more enjoyable through the year.        
    
    

Wintering Crows and Gulls

     Flocks of American crows and ring-billed gulls wintering in Lancaster County, Pennsylvania croplands are interesting and entertaining.  The crows are here from their nesting territories in Canadian forests and gulls are here from breeding grounds around the Great Lakes and the St. Lawrence River.  These species are about the same size, winter in groups and feed on waste grain and invertebrates on fields, as long as the ground is ice-free.  Their great numbers and larger size are exciting in the air, on the ground and on their roosts, making them inspiring to experience.  The crows dot the fields black while the ring-bills speckle them gray and white. 
     Both species are adapted to the fields they feed in.  Gulls traditionally winter on beaches and salt marshes so they readily have adapted to wintering on vast open spaces near larger bodies of water.  Crows are forest edge birds, having nested in trees and feeding in clearings.  For them, the clearings got much bigger with the introduction of agriculture here, as elsewhere. 
     Early each morning, thousands of crows noisily leave their overnight, winter roosts in trees around a shopping mall called Park City.  Strings and sheets of them casually spread across the countryside to feeding fields where they spend the day devouring whatever is edible to them.  By mid-afternoon trickles, then streams, then rivers of crows fly back to the overnight roosting site, merging with more and more aerial waterways of them as they get closer to the roost.  And the larger the floods of crows are, the more noisy they are as they flow across the sky and perch in trees near the ultimate roost.  Finally, just as darkness settles across the land, the crows perch for the night, still cawing through much of the night.
     The local gulls perch overnight on island beaches in the Susquehanna River and on water or ice on larger, human-made impoundments.  In the morning, the gulls silently pour off the river or lakes in V's, strings and loose masses and swiftly pump out to the fields to feed.  But like the crows, by mid-afternoon they start back to their nightly perches.  The gulls are power flyers on pointed, swept-back wings.  Masses of ring-bills in long strings, V's and hordes pass across the sky to their overnight resting places, creating even more exciting spectacles in their silence than even the noisy crows are capable of.
     Both these species are highly adaptable, taking advantage of every opportunity to get food.  If fields are covered with snow, the crows will eat out of land fills, dumpsters and parking lots, feed lots for cattle, bird feeders, and on road kills.  The gulls will catch fish or scavenge dead fish from running water that doesn't freeze and eat out of land fills, dumpsters and parking lots until other food sources open again. 
     American crows and ring-billed gulls wintering in Lancaster County add much life, beauty, excitement and intrigue to its agricultural areas.  We often can see those adaptable and interesting birds in the fields or the air just by driving through the countryside.  But by March, both species are going north to their respective breeding territories.  We are then busy enjoying spring and the plants and wildlife that is obvious during that vernal season.   
            
    

Farm Animal Divergence

     Related wild animals diverge from each other to take advantage of different niches to lessen competition for space and food with their relatives.  And two-toed farm animals, though they have been domesticated for thousands of years, still demonstrate the divergence of their ancestors to use different food sources, which eases competition among them.  Cattle, sheep, goats and pigs, for example get food in various niches and in different ways.
     Cattle graze on grass, but they do better eating lush grass in large, relatively flatter meadows without rocks and other obstructions.  Sheep also graze on grass, but they do very well with very short grass in rough terrain and smaller pastures.  Sheep do well where cattle are not as likely to.  In fact, sheep are pastured where cows would not prosper as well.  But, of course, there is some overlap between those two species. 
     Goats are closely related to sheep.  But goats do better browsing twigs and coarse vegetation in even rougher terrain than even the sheep could handle.  Again, there is some overlap between these two species, but there is divergence, too, reducing competition for food between them.
     Pigs really diverge from their relatives.  Although pigs will eat anything, anywhere, they will most likely root in the soil and fallen leaves for whatever is edible, something none of their relatives do.  But pigs have tough, flexible snouts for digging in the ground for roots, seeds and anything else, both vegetative or animal, they can shovel up and swallow.  But they are destructive, really ripping up the soil in the process and, perhaps, killing more plants and animals than they eat.  But they are not competing much with their relatives for food.
     These are just a few examples of domesticated animals whose ancestors diverged from a common ancestor to take advantage of different food sources in various niches.  This principle exists through
all of life.         

Black Vulture Roost

     One morning in the middle of December of 2014, I was driving through the wooded and suburban Welsh Mountains located south of New Holland in Lancaster County, Pennsylvania.  While moving along, I happened to see a half dozen black vultures perched handsomely on the roof and chimney of a house along the road I was on.  I remembered, "oh, yeah, I had seen black vultures on that house before a few years ago" and they're still roosting there. 
     So this time, as I drove by the house a couple of times to see it and its yard from different angles, I counted 16 black vultures, six on the house, another four on the roof of a shed, five on a couple of trees in the yard near the house and one on the lawn.  I didn't stop to count the stately vultures because I didn't want to alarm anyone, including those large, black birds.
     I have seen mixed winter vulture roosts before of both black and turkey vultures, mostly in tall, planted coniferous trees  in various  forested valleys in Lancaster County and neighboring counties.  The needled trees and hills of the wooded valleys offer some protection from cold wind to the wintering birds.  But I never saw vultures of either local kind perching on a home and its adjacent lawn.  I wondered how that habit started, and why it has persisted for at least a few years.  I don't know and I am not going to ask the home owners to respect their privacy, and that of the vultures.
     Turkey vultures have always been in Lancaster County in my lifetime.  I saw them soaring high over farmland outside Rohrerstown when I was a boy many years ago.
     But it seems that black vultures were relative newcomers to this area in 1974.  I heard that a few those vultures were spotted in the Furnace Hills of northern Lancaster County during that year.  Wanting to see that species, which would be for the first time in my life, I climbed the Cornwall Fire Tower steps as high as I could go a few times during October of that year.  I never did see black vultures that autumn, but I did see migrating hawks going by that tower, which led to the Lancaster County Bird Club conducting hawk migration watches each fall from 1975 until 1988.  However, I did see several dignified black vultures with turkey vultures on a winter roost in a wooded ravine near the Susquehanna River in southern Lancaster County and another mixed roost in conifers in a wooded valley in southern Lebanon County.   
     Black vultures and turkey vultures are devout scavengers and live abundantly in southeastern Pennsylvania, as well as across much of all the Americas, because of abundant farmland and dead farm animals discarded in the fields.  Most every day in Lancaster County, one can see both types of vultures soaring and watching for carrion below.  Both species have good eyesight and turkey vultures have an excellent sense of smell, which is unusual for birds.  But that keen sense of smell enabled turkey vultures to find dead animals hidden from sight under the canopy of the forests that once covered this area and a large part of the Americas.      
     Groups of turkey vultures and black vultures roost in the Welsh Mountains during winter nights.  And they pair off in spring to nest in those same wooded hills during the warmer months.  All year they have easy access to croplands around those wooded hills, where they almost daily search for food.   
     Vultures keep an eye on each other as they watch the ground for carrion.  When a vulture suddenly swirls to the ground, other vultures are alerted to the possible presence of a dead critter.  The sudden traffic of vultures soaring earthward is a signal that spreads out like a ripple on a pond and vultures from miles around converge on the carcass to get their share of meat.
     The two species of vultures in southeastern Pennsylvania, as everywhere, are interesting to observe.  Especially when these adaptable birds roost so close to human habitation.      

Birds Wintering at Conewingo Dam

     Conowingo Dam on the Susquehanna River in northern Maryland is a good place to experience wintering water birds, particularly when local impoundments and much of the river freezes over, blocking access to fish.  Water falling through the turbines of the dam to generate electricity wells up below the dam with such force that it doesn't freeze, offering access to fish.  Therefore, wintering, fish-eating birds congregate in good numbers to dine on that finny prey. 
     The most abundant and obvious of fish-catching birds at Conowingo, blizzards of pale-gray and white ring-billed gulls swirl in the wind low over the river below the dam to watch for small fish in the up-welling water.  When prey is spotted, the ring-bills drop to the turbulent water, beak-first, to grab fish in their bills.  Meanwhile, other ring-bills, in groups, rest and digest between fishing forays on mid-river boulders.
     Scores each of herring and great black-backed gulls also winter at Conowingo, where they catch live fish and scavenge dead ones.  Both these species are larger than ring-bills, but the herring gulls are colored like ring-bills.  The magnificent great black-backs, however, are white all over, except for black upper wings and backs, making them look something like bald eagles, except eagles have dark bellies.  The goose-sized black-backs not only scavenge dead fish and other animals, but also steal fish from the ring-bills and other kinds of fish-catching birds.  Herring and black-back gulls, too, rest on boulders in the river when not searching for food.
     Sixty to over a hundred bald eagles, both adult and immature, winter at this dam.  There they catch larger fish, ducks and other critters along the river, and scavenge the dead of those same species that wash up on boulders or shore.  At any time during a winter day, these majestic eagles may be spotted perching on trees along the river, or mid-river rocks and power towers, or soaring on high.          
     To catch live fish, bald eagles swoop down to the water's surface and snare their victims with their long, powerful talons, without their bodies touching the water.  Then they power-flap to a rock or tree to eat their catch. 
     Up to a hundred stately great blue herons stand on shores and mid-river boulders where they stalk live fish of various sizes in shallow water.  These long-legged and long-necked birds generally are hard to see in bare trees and on rocks because they are gray, which camouflages them on those natural objects.
     Several fish-catching birds of four species, including common merganser ducks, double-crested cormorants, common loons and horned grebes, dive under water from the surface to catch small fish.  These birds are all built like boats (convergence) because of their living on water.  The mergansers and cormorants winter in flocks on water in winter, but loons and grebes are more solitary.  A field guide to birds may be needed to identify these similar water species.
     Over a hundred each of turkey vultures and black vultures winter at Conowingo Dam in the Susquehanna because they, too, scavenge dead fish and other creatures.  In winter, flocks of them roost overnight in trees near the river and perch on rocks and trees along the water during the day to watch for dead animals to eat. 
     Many crows winter at Conowingo Dam where they, too, watch for dead fish and other animals to consume, though they must compete with gulls, eagles and vultures for that food.  But these intelligent birds persistently watch for opportunities and are able to scavenge carcasses in spite of larger competition for them. 
     Interestingly, crows, as well as gulls, also pick dead or stunned small fish that went through the turbines from the surface of the moving water.  The crows, however, perch on trees to swallow their catches, then fly over the river for more.
     Visit Conowingo Dam in winter to experience these interesting water birds.  They are entertaining, and teach us about taking advantage of human activities, survival and competition for food.
           

Symbolic Trees

     There are four major habitats in Lancaster County. Pennsylvania- waterways and impoundments, urban and suburban areas, farmland and woodland.  And each habitat has a tree that is symbolic of it.  Though one species in several, each symbolic tree is the most outstanding, most representative of its habitat, whether natural or human-made.
     Big, tall, stately sycamore trees are the most typical ones along creeks and ponds.  Massive sycamores with large, gnarled branches are easily noticed from a distance because they have light and darker mottled bark that stands out before the darker bark of silver maples, ash-leafed maples and black walnut trees that are also common on floodplains, but not as outstanding as sycamores.  Lines of sycamores seen from a distance indicate the presence of water at their roots.
     Many larger sycamores are riddled with cavities where wind ripped limbs off the trees.  There a variety of creatures live and reproduce, including raccoons, wood ducks, screech owls and others.
     Norway spruce trees are the most typical species of urban and suburban habitats.  Of course, several other kinds of trees flourish in those built habitats, but many of them also live in our woods.  Norway spruces, being from Europe originally, have long been planted on lawns, and there they are confined.  White pines and eastern hemlocks are also planted on lawns, but they are also wild in spots in this county.
     Though it is an alien kind of tree, Norway spruces are a good species to plant on lawns.  They don't seem to get diseases readily.  They don't snap off in wind as do many white pines.  They don't seem to be invasive and they have handsome shapes all their lives, attractive, needled boughs through the year and long, striking cones that are pretty in the trees, on lawns and in dried arrangements.  Squirrels, mice and a variety of small, seed-eating birds eat the winged seeds in their cones, and those that already fell from the cones.  Mourning doves, great horned owls, red-tailed hawks and Cooper's hawks are some of the birds that roost in these wind-breaking spruces through winter.
     The rugged, spindly black locust trees are the most representative of Lancaster County farmlands.  Some of them grow alone in fields, while other form lines along roadsides and hedgerows.  The deeply-furrowed bark of black locust appears gnarled and twisted, like mighty muscles straining.  And because its wood does not easily rot in the soil, some black locusts are made into fence posts. 
     Black locust trees bloom during the last two months of May in this area.  Their multitudes of
 sweet-scented blossoms are white and grow in many clusters.  Their fragrance is strong on the breeze and can be smelled from a bit of a distance, making cropland more enjoyable in mid-May.  Honey bees and other kinds of insects swarm over the flowers to sip sugary nectar and ingest dusty pollen.
     A few beans develop in each of several small, brown pods that grow from the fertilized blooms.  Mice, squirrels and a few kinds of birds eat many of those beans.
     Tall, stately tulip trees, or tulip poplar trees, are the most characteristic species of local woodlands.  The trunks of this type of tree grow tall, and as straight as telephone poles.  Their bark is shallowly furrowed and they have tulip shaped and sized flowers during the last two weeks in May.  We generally don't see their pale green blossoms with a band of orange near the base of each one because they develop near the tops of the trees.  However, strong winds in May might knock some limbs out of the trees and dash them to the ground.  Then we get to see their lovely blossoms.
     Bees and other kinds of insects eagerly visit tulip tree blooms to sip nectar and consume pollen.  The resulting seeds of that pollination are beige with thin wings on each one for spinning away on the wind some distance from the parent trees.  Mice and squirrels eat many of those seeds through winter.  The two-inch spikes those seeds developed on remain in the trees and resemble tooth picks.
     The wood of tulip trees is used for pulp for paper and cheap lumber.  And these trees are planted on some lawns for their attractive shapes and the shade their leaves provide.
     Each local habitat has at least one tree that is characteristic of it.  And each tree adds beauties to their environment that we all can enjoy through the year.      
      
    

Stages of Winter

     Winter in southeastern Pennsylvania has five predictable, but arbitrary, stages, a beginning, when that season becomes more intense, mid-winter, when daylight per day gets noticeably longer, and its ending and overlapping with early spring.  Each stage doesn't have a precise date, but each occurs about the same time annually.
     Winter truly begins around the tenth of November.  At this time, the weather could still be warm in the afternoons, but the amount of daylight each succeeding day continues to shorten.  Most leaves have died and fallen from their twig moorings, most other vegetation is dormant and the majority of bird migrations are already completed by that time.  And the "look" and "feel" of winter dominates the landscape.
     Around the tenth of December, the weather turns much colder, often bitter cold, and there will be few, if any, warm afternoons.  Winter weather is really upon us.  And by now, periods of daylight each day are as short as they are going to get, with sunset being about 4:40 PM for a few weeks.  Snow that falls now usually remains for some time.          
     December 21st is mid-winter.  Now the sun "won't travel any farther south" and daylight per day will get no shorter.  In fact, daylight each day now will get longer by a couple of minutes each succeeding day, but a few weeks will pass before we can readily see a significant difference in the lengthening amount of daylight per day. 
     Local weather is at its coldest around the middle of January.  Cold fronts with frigid temperatures, sunlight and low humidity roar south.  High temperatures per day might be in the teens or lower.  Snow and ice are not going to melt.  But in spite of the intense cold, daylight each succeeding day gets noticeably longer, perhaps taking a bit of the sting from the bitter cold in our imaginations.  And that lengthening of daylight each day is the first promise that the "sun is coming north again", bringing spring with it.  
     And around the tenth of February, spring begins in the local area.  Daylight per day is much longer than it was in December, but wintry weather could strike at any time.  However, that weather can vanish just as readily in the warmer sunshine.  There is a constant struggle between mild weather and cold weather through February.  Wildlife and vegetation in the midst of that contest have to be adaptable and tough, which they are.  Geese and swans starting their migrations north at this time.  Permanent resident, small birds, including tufted titmice, song sparrows, house finches and mourning doves, sing territorial songs during warm February afternoons.  Male wood chucks prowl across the still austere landscape in search of mates during the day and male wood cocks dance and sing for mates each dusk.  Meanwhile, skunk cabbage, snow drop, winter aconite and chickweed flowers are in bloom by this time, sometimes under a blanketing, protective layer of snow.  The "feel" of spring is in the air.
     All these arbitrary parts of winter overlap each other and are never precisely on time.  But they are undeniable.  Watch for them during successive winters to come.     
       

Beauties of Snow

     We know snow can be dangerous and generally annoying.  But it has several beauties, too.  And it enhances the beauties of woods, suburbs and fields in the Middle Atlantic States, as elsewhere.
     The sky is uniformly gray before and during a snowfall.  Falling snow is silent, and pretty, especially when dropping before needled conifers and bare deciduous trees that create dark backgrounds.  The flakes are innumerable and no two are exactly alike.  And they pile on top of each other, inch by inch.
     Snow on the ground changes the look of a landscape, making it appear more wild and desolate.  Roads and trails disappear, for a while. 
     Blankets of snow on the ground provide protection for small creatures against predation and insulation for plants and invertebrates against air temperatures colder than the snow.  Field mice dig tunnels through the snow at short-grass level.  There they feed, make grass nests and move about without being seen by predators.  But when the snow melts, there are the tunnels visible to scrutiny.
     Wet snow sticks to every bare twig and needled bough, outlining the lovely shapes of each and every one of them, and accentuating the beauties of the trees.  Every twig and needled limb is an artistic study of white on dark, especially at dusk. 
     Some evergreen branches are pushed down by the weight of the snow on them, providing wind breaks for birds, squirrels and other mammals nestled in those trees.  But the wind blows some of the snow off the trees in great, powdery showers that you wouldn't want to be caught under.
     Wind pushes dry snow off some places in the fields and piles it in others.  Horned larks, sparrows, ducks, geese, doves and other kinds of field birds eat seeds and grain from the soil swept free of snow by the wind.
     Dry snow drifts easily in vast sheets before the wind across fields, creating drifts and sculptures of heaped snow that constantly change shape.  And during a brilliant sunset, drifting snow on fields is pink and looks like smoke blowing across the open landscape, as if the whole farmland was on fire. 
     Outdoor lights bouncing off falling snow, fallen snow and the cloud cover at night brightens the landscape almost like day.  Trees and shrubbery are silhouetted against the clouds and ground cover, and deer and rabbits are charcoal etchings before the fallen snow. 
     Snow on gray twigs, red berries, green needles and other objects melts and refreezes as a result of fluctuating temperatures.  Melting snow drips, but those drops become frozen on each other as the temperature falls, creating beautiful, transparent icicles in great numbers everywhere. 
     Fog is caused by warm air circulating over snow on the ground.  The fog and ground cover of snow block the horizon and obliterate details of the landscape, making it austere, and charming in its own cold, wild way.
     Another intrigue of snow on the ground is the signs that wild animals leave behind of their travels and adventures in the snow.  Readily seen tracks are those of deer, rabbits, squirrels, opossums, foxes, crows, ducks and a variety of small birds.  One can read the signs of tracks to know what kinds of wildlife were in an area, where they went and what they might have been doing.  Sometimes bits of blood, fur or feathers on the snow tell of an ambush on the snow.   
     Enjoy the many beauties of snow before it melts away.  It is perishable, often fleeting, and not here every day.         

Winter Birds at Safe Harbor

     Several kinds of larger birds can be spotted each winter at Safe Harbor Dam on the Susquehanna River in Lancaster County, Pennsylvania, especially when most of the rest of the river freezes.  In fact, the more frozen the rest of the river is, the more birds will be seen just below Safe Harbor and other dams along the river.  And each species has a reason for wintering there, making them predictable to see every winter.
     Water below the dam is always open because it tumbles through turbines to generate electricity and wells up below the dam with force, keeping the water from freezing.  Therefore, fish-catching birds and scavengers can make a living just below the dam when all other impoundments and much of the river is frozen.
     The Susquehanna River and Safe Harbor Dam are sandwiched between steep, wooded slopes that shelter the river and its birds to some extent.  The eastern hills are in Lancaster County while those on the west bank are in York County.  A parking lot at Safe Harbor Dam on the Lancaster County side offers easy access to this part of the river the year around. 
     Gulls are the most easily noticed birds along the Susquehanna because they are numerous there in winter, large and white underneath.  Three types are along the river- ring-bills, herrings and great black backs.  The black backs have black upper wings and backs, while the other two species are pale-gray above.  All the gulls can be spotted flying powerfully or floating gracefully in the air at all levels.  Or they may be resting on the water or perched in groups on boulders in mid-river.   
     Gulls catch small fish from the surface of water and scavenge dead fish they find floating on the water or washed up on a shore.  Black-backs also pirate fish from the smaller herring and ring-billed gulls whenever they can.
     A half dozen or more bald eagles, both adults and immatures, are spotted around Safe Harbor Dam.  They can be seen perched in trees on the slopes and the wooded river islands, or on power towers and mid-river boulders, or soaring magnificently in the sky.  But wherever noticed, they are always majestic. 
     Bald eagles catch large fish from the river, or pirate them from gulls.  And the eagles are devout scavengers, cleaning up dead fish, ducks, gulls or whatever other kinds of critters.
     Turkey vultures and black vultures specialize in scavenging.  Flocks of each species soar gracefully on high as they watch the ground for dead animals.  Turkey vultures have a good sense of smell and can sniff out dead animals.  Black vultures see carcasses from the air and also watch the turkey vultures for any sign of their floating to the ground or a shoreline after a dead animal. 
     Flocks of wintering American crows also scavenge dead animals they find and can keep from the vultures and eagles.  The crows are usually seen on the shores and boulders of the river where they scavenge dead animals and rest.
     Great blue herons are large birds, standing over four and a half feet tall.  They have long legs for wading in water and lengthy necks and beaks to reach out and snare fish of various sizes in their bills.  All fish are swallowed head-first and whole. 
     Flocks of black ducks and common merganser ducks also live on the river at Safe Harbor each winter.  Black ducks leave the river each evening at dusk to fly out to harvested corn fields where they shovel up waste kernels of corn.  The mergansers, on the other hand, stay on the Susquehanna where they dive under the surface to snare small fish in their serrated beaks that hold fast to the slippery prey.
    Rock pigeons live on the dam itself.  Pigeons are originally from rocky cliffs along the Mediterranean Sea in Europe and North Africa.  Wild pigeons are gray, which camouflages them on the rock walls.  To the birds at Safe Harbor, the dam is a cliff above a body of water. 
     A couple times a day, the pigeons leave the dam and go to fields in farmland where they ingest waste grain and seeds.  They make a porridge of those seeds to feed to their young on their nests.
     All the bird species discussed above have reasons for living at Safe Harbor Dam, as they do on any other dam.  And they make those dams and the rivers they block more interesting.               
    
    
         

Feathered Masters of Disguise

     American bitterns are members of the heron family and have the long legs, necks and beaks to prove it.  Bitterns' habitats are patches of cattails and phragmites that emerge from mud in shallow water and form marshes around inland ponds and wetlands, and along estuaries and sea coasts, where they hunt for food and raise young each year on cattail platforms on the ground near water.  There, on occasion, I have heard the pumping songs of male bitterns that were establishing nesting territories. And there bitterns stalk small fish, tadpoles, frogs, small snakes, insects and other creatures of wetlands to feed themselves and their young. 
     Bitterns plumages are brown, streaked with black, which camouflages them as they carefully skulk among cattails and phragmites.  Indeed, American bitterns are difficult to spot in their native habitats.  I have seen a few, only by chance, by seeing through their camouflage.   
     American bitterns, as all forms of life, are built to help them catch their meals.  Bitterns sneak slowly and cautiously through cattails and phragmites to sneak up on unsuspecting prey in the shallows.  They have long legs for wading in water, as do all their heron kin.  And they have long toes on each foot that work like snow shoes, by spreading the weight of the birds across the mud so they don't sink in it and get stuck in the mud, allowing the escape of potential victims.  They also have a lengthy and curved nail on each toe that helps them get a grip on the mud as they wade the shallows.  Slipping in the mud creates jerky motions, indicating to prey that potential danger is near, causing them to flee.  
     Bitterns, like all their heron relatives, have lengthy necks and bills to reach out and grab prey.  Each bittern moves slowly and quietly to within striking distance of its victims, throws out its long neck and, hopefully, snares the food animals it targeted.  They are not successful with every plunge at prey, but often enough to be well fed.          
     Bitterns have another couple of tricks that allow them to blend well into their background.  They have long, lengthwise stripes of orange-brown on their throats.  When they think they are spotted by a predator, or they don't want to noticed by potential prey, they stand still and stretch their necks skyward, revealing those stripes that resemble cattails or phragmites.  Those throat streaks mimic the reeds in the marshes, which is a form of blending in to the point of being invisible.  And to add to that mimicry, if the reeds sway in the wind, the bittern weaves back and forth with them.  I have seen a couple of bitterns doing that on the edges of a couple of cattail marshes.
     How do the bitterns know they have vertical streaks on their throats and how do they know to rock with the cattails and phragmites in the wind to enhance the mimicry?  I don't think they know the answer to either question.  Those stripes happen to be on their throats by chance and the birds'
 swaying with the wind as protective mimicry just happened to work out right for the bitterns of long ago.  They have purposefully done nothing.  The bitterns that had those two traits by luck were able to survive long enough to reproduce, passing their genes for those characteristics on to their offspring, generation after generation.
     And so it is with all life.  Individuals are born with traits that aid in survival and reproduction, passing successful genes to their descendants.  American bitterns are a successful species, though seldom seen because of their retiring habits and dense habitats through each year.  They do have
unique characteristics that protect them and help them catch food, adding to their success.                 

Long-legged Waders

     Several kinds of long-legged, wading bird species live and nest in the eastern United States, including great blue herons, great egrets, glossy ibis, white ibis, sand-hill cranes, wood storks, roseate spoonbills and limpkins.  These are all large, impressive birds that have long necks and beaks for reaching out to snare prey and lengthy and legs for wading in water, though they come from different bird families.  But their ways of life are somewhat alike in similar habitats.  Therefore they have characteristics in common.  All these species fly with their necks and legs stretched out for balance, except the herons and egrets that fly with their necks pulled back in an S shape. 
     Each kind is attractive in its own way.  And most species are more or less gregarious, particularly when nesting in colonies of their own making, or in mixed groups with other kinds of large, wading birds.  Only the limpkin is a solitary species. 
     Great blue herons and great egrets are the largest members of the heron family that wades in water and catches small fish, frogs, snakes, insects and other aquatic creatures.  Great blues and great egrets also catch mice in meadows and dunk them in water to slick their fur before swallowing them head first and whole.  Great blues are grey with black markings on the head, while great egrets are white with black legs and yellow beaks. 
     Glossy ibis and white ibis have decurved beaks, a way to identify these species.  Glossy ibis are dark and nest along the Atlantic coast from Delaware south to Florida.  White ibis live and nest from South Carolina to Louisiana and in much of South America.  Both these species feed on insects and other invertebrates in wet meadows and small, water creatures in wetlands.  Glossy ibis are dark, ruddy-brown all over, while white ibis are white with black wing tips.
     Sand-hill cranes are common in North America and mostly nest on northern prairies, raising one chick each year.  They have gray plumage all over and one red spot of bare skin on their head.  Their call is a loud, deep, rolling "gur-roo", repeated again and again.  This species feeds on roots, and tender shoots, grain, seeds, berries, insects, mice, frogs and other small critters on dry soil, but also in marshes.   
     Sand-hills, like all crane species, have elaborate courtship dances for pair-bonding in spring.  This species migrates in great flocks, many of which spend a few weeks in March resting on sand bars in the Platte River of Nebraska between their feeding forays. 
     Wood storks are the only member of their world-wide family in North America.  They have slightly decurved beaks they use for picking up aquatic creatures in water and on the surrounding land, including frogs, mice, insects and crayfish. 
     Wood storks are mostly white with black wing tips and bare heads and necks.  They nest in stick nurseries in colonies in trees in swamps from South Carolina to the Gulf Coast, and in much of South America.     
     Roseate spoonbills are uncommon in North America, but more abundant in South America.  Young of the year are white, but adults have hot-pink wings that make the birds attractive.  Birds of all ages, however, have long bills that are horizontally flattened at their tips.  They swirl their beaks back and forth in shallow water to sieve out small marine life from the water and mud.  Roseates nest in stick cradles in trees in Florida swamps.
     Limpkins resemble herons, but are not in that family.  This bird lives and nests mostly in Florida 
swamps.  This is a nocturnal species when it does most of its hunting of food.  Then one might hear its loud "kr-ow".  Limpkins are brown with white spots throughout their feathering for camouflage.  They eat mostly snails and other little critters.  And each pair builds a cradle of leaves and stems
 attached to plants just above the water level or in vines low in shrubs along the water's edge. 
     These birds are somewhat alike in appearance because of similar habitats and life styles, which is called convergence.  Habitats certainly do shape the creatures dwelling in them.       

Why Metamorphosis

     We know metamorphosis means changing from one form to another.  We know that most kinds of insects metamorphosis at some point in their life histories.  We know that it is a process that is mysterious and miraculous at once.  How do the insects know what to do?  They don't: They only follow their instincts.  And we know the four stages of complete metamorphosis- eggs, larvae, pupae and adult. 
     The most dramatic, and, probably, best known example of change from one life stage to the next in insects is among the moths and butterflies, particularly the latter grouping.  We know how metamorphosis happens, but we don't know when that phenomena of life began among insects.  And how many people think about what its benefits are, or why it occurs at all?
     As among most species of insects, eggs are the first step of complete metamorphosis.  Among butterflies, the females must lay eggs on certain plants because the caterpillars of each kind of butterfly will eat only one to a few different kinds of plants.  This is unfortunate because if their food plants become extinct, so may the butterfly species dependent on them for food. 
     The caterpillars of each type of butterfly hatch as eating machines, consuming their appointed food almost constantly.  The caterpillars eat and grow rapidly for about two weeks or more, depending on the species, and get bigger and fatter each successive day.
     When each larva can't eat anymore or get any bigger, it stops consuming food altogether and
 forms a protective pupa or cocoon around itself as a shelter where it can change into a butterfly.  The larva becomes dormant, and probably unconscious, as its body cells rearrange themselves to form the butterfly, including with wings.
     When the change of each caterpillar is complete in a few weeks, the butterfly comes out of its stiff pupa.  It perches near its empty chrysalis for a few hours while drying, pumping out and stiffening its wings and otherwise gaining strength for its first flight.
     But what is the advantage of being a winged butterfly?  Each caterpillar eats and grows until full-sized.  It could also become mature as a wingless caterpillar and lay eggs on the plants it just ingested for the next generation of its species.  And, if they did that, there would be no need to waste time and energy in a pupa that is more vulnerable to predation than the caterpillar.  But, perhaps, they ate all the plants of the types they are genetically equipped for.  Now, as winged adults, they must seek proper food plants elsewhere.
     Insects that sip nectar from flowers, as butterflies do, for example, often have to travel over large areas of land to find enough sugary nectar, and dusty pollen, to satisfy their food needs.  And males of each species of butterfly may also have to travel some distance to find a mate to ensure the next generation.  And females of each kind need to travel over acres to find the right plants to lay their eggs on.  Wings are important. 
     Caterpillars, without wings, can't travel like that.  But they can when they become winged adults, the butterflies.  Of course, each larva and its mature form are the same insect, but only the latter form has the ability to fly long distances to find food and mates, thus ensuring the future of its kind.  Caterpillars could never travel far enough, fast enough to save their own species.  So the third stage of complete metamorphosis is important; to provide the quiet, motionless stability needed in little cases of rigid skin (pupae) made by the caterpillars themselves to contain and rearrange body cells to form the mature insect.  And that is why many kinds of insects have that energy-consuming, relatively-risky pupa stage- to mature and grow wings to ensure the next generation of themselves.
     Metamorphosis is miraculous.  When and how it started is a mystery.  But it, and all of nature, is nothing we could create. 

          

Two Species, Same Habitat, Different Times

     While walking along a tumbling stream in woodland one recent winter afternoon, I noticed a slight movement near the water's edge.  Looking at that spot with binoculars, I quickly noticed a winter wren hopping about among a tangle of tree roots in the stream bank.  Winter wrens, like all their feathered clan, are brown and smaller than sparrows, making them camouflaged on woodland floors and along stream banks.  They are impossible to see until they move. 
     While watching the wren briefly, I remembered seeing a pair of Louisiana waterthrushes nesting along that same section of stream this past summer.  Here in Lancaster County, Pennsylvania, as elsewhere in eastern North America, winter wrens and Louisiana waterthrushes use the same
 charming, musical streams in woodlands, the wren in winter to forage for invertebrate food kept active by the running water and sheltering tree roots, and the waterthrushes in summer to raise young.  Both kinds of birds use those same beautiful habitats, but not at the same time for the most part.  However, they might overlap each other early in April when the waterthrushes have returned here to nest, but the wrens hadn't left yet to push farther north to breed. 
     Winter wrens and waterthrushes aren't related and don't look alike, but both are insectivorous, finding food under carpets of fallen leaves on forest floors, in brush piles, under fallen logs, in crevices between boulders, among exposed and tangled tree roots in stream banks and along the water's edge.  Males of each species have loud voices so females of their respective kinds can hear them amid the rush of water and find them for mating.
     Winter wrens breed in spruce/fir forests of the northeastern United States and eastern Canada.  And they winter along streams in deciduous woods in much of the Lower 48.  Each wren is a stub-tailed, mouse of a bird that creeps about on leafy, forest floors and stream banks in search of invertebrate food.  Those sheltered places harbor tiny critters the wrens seek, particularly after a snow fall when much invertebrate food is buried under snow.  And the running water on stream edges doesn't freeze, keeping some invertebrates active and available through winter, the reason why winter wrens are in that niche at that time.                
     Louisiana waterthrushes winter in the forests of Central America, but nest in wooded stream valleys in the eastern half of the United States.  They tuck their cradles of dead leaves and grass in niches under tree roots in stream banks in the woods where they are protected from most predators, except mink and black rat snakes. 
     Playing the role of sandpipers where that family of birds would not be, waterthrushes forage mostly for invertebrates in the stony shallows of the streams where they build their nurseries.  As they walk along the water's edges and among the pebbles, waterthrushes bob and dance like debris bouncing along in the flowing water, which is a form of camouflage, confusing would-be predators.
Birds of this species are also difficult to notice until they move, or fly stiff-winged and swiftly across the waterway.
     These species of birds share a similar habitat, but usually not at the same time.  And they are both hard to spot.  Often they are heard before seen.  But they are interesting little creatures when along streams in the woods, making that habitat more interesting.      

Birds on Atlantic Beaches and Jetties in Winter

     Five kinds of birds regularly winter on the beaches and rock jetties of the Atlantic Coast.  And in winter, they all feed on small crustaceans, molluscs, insects, worms and other invertebrates on the sandy beaches and boulders piled at 45 degree angles from the beaches to protect their sand from wave erosion.  But they do so on different parts of those habitats, and by using different, interesting techniques, which reduces competition among them for food.  The five species are sanderlings and dunlin, which are types of sandpipers on the beaches, and purple sandpipers, ruddy turnstones, which are another kind of sandpiper, and harlequin ducks on the jetties.
     Sanderlings are light in color in winter to blend into the background of sand to be nearly invisible, until they move.  Camouflage on creatures protects them from predation.  
     Sanderling flocks run up the beaches ahead of incoming wavelets, but quickly turn around and chase those same little waves when they slide down the beach to the ocean.  Sanderlings pick up and eat tiny invertebrates stranded in the foam on the sand as the water recedes.  And it's entertaining to watch their curious way of feeding.
     Also the color of sand in winter, gatherings of dunlin mostly get their invertebrate food on beaches by probing into the sand with their sturdy beaks.  Dunlin constantly move about, mostly by flying into the wind low to the sand as a group, as they deplete food in the parts of the beaches they visit.
     Purple sandpipers are not purple, but a bit dark like the boulders they live on in winter, which camouflages them.  They really can not be seen until they move.  This kind of sandpiper walks individually or in tiny gatherings over the boulders and consumes invertebrates already on them, and those dumped by waves splashing almost constantly over the rocks.  
      Ruddy turnstones are white and chocolate in color in winter.  Their color patterns break up their shapes, making them difficult to see.  They, too, walk on the boulders, flipping over stones and shells with their strong bills to grab invertebrates that might be hiding under them, something the purple sandpipers don't do to get food. 
     Harlequin ducks repeatedly dive under water near the jetties to get invertebrate food at the bottom of the shallow water, but soon pop up again to get air.  They also must be careful not to be dashed against the rocks by the waves.
     Harlequin drakes are small, beautiful ducks, with gray, chestnut, black and white feathering in striking patterns that also break up their patterns for camouflage.  Their mates, however, are dark brown, with a bit of white patterns that will make them invisible, which is especially beneficial when they are raising young in inland Canada.
     If on a sandy beach or by a rock jetty along the Atlantic Coast in winter, look for these birds in those habitats.  They will make a days on winter beaches more interesting.           

Rodent Teeth

    Rodents include mice, rats, squirrels, chipmunks, beavers, porcupines, and many other species that live worldwide.  Rodents, such as mice, squirrels and beavers, have similarly shaped teeth that reveals their common ancestry and consume hard foods that require sharp front teeth and strong jaws to break down that food. 
     Rodents long ago ate hard foods because that type of food was available to them.  And, over the course of the life histories of these furry mammals, they developed teeth ever better adapted to such food.  Necessity IS the mother of invention.  And form does follow function.  Mice consume seeds, squirrels chew open nut shells to get the meat inside and beavers ingest twigs and bark from the trees they chew down with their large, orange front teeth. 
     But teeth wear down chewing such hard food, eventually becoming useless and allowing their owners to die of starvation or predation after the animals weakened.  Those animals reproduced little, if at all.  But by chance in the distant past, some rodents' teeth became genetically structured to grow throughout the lives of their owners.  That eliminated the problem of teeth wearing down, but if the teeth grew faster than they could be chewed down, the lower teeth could grow into the skull and the upper teeth could grow into the lower jaw, perhaps locking the mouth shut which again would lead to starvation or predation.  So, over many generations of rodents, a balance between the growth of teeth and their being worn down developed, to the benefit of surviving rodents to this day.
     All rodents today have similarly shaped teeth that are successfully balanced between their growth and wearing down from chewing hard food.  That similarity to me indicates that today's rodents are related to each other.  They are the surviving descendants of one species that was a member of a larger family of rodents in the long ago past.  Species of rodents that could not strike a balance between the growth and the wearing of their teeth became extinct, providing open niches for surviving rodents.
     The balance of the growth of rodent teeth and their wearing down is just one of innumerable changes in nature over eons that led to today's successful species.  And some of that current life won't be successful in the future.  Life is forever facing changes, including human-made ones, that eliminate some species, but make room for new, perhaps better adapted ones.  Life is never static.
      

Painted Turtles

     As I write this on the morning of November 26, 2014 in Lancaster County, Pennsylvania, the temperature is in the 40's, rain is falling and 3 to 5 inches of snow are in the forecast for the afternoon.  The weather has the look and feel of winter.  Yet two days ago the weather was partly sunny with temperatures in the 60's, a good day to be outside, which I was.  I saw some birds of various kinds and lovely scenery, but at least 37 eastern painted turtles sunning themselves were the most interesting wildlife I noted that day.
     A couple of weeks before in the Mid-Atlantic States, temperatures dropped unusually low for November and ice formed on impoundments and puddles.  No cold-blooded creatures, including painted turtles, would have been active then.  But many critters are adaptable and respond quickly to changing conditions to their own benefit, as do painted turtles.  And when the weather warmed, there they were sunning themselves, as they do during warmer months each year.  I was startled to see so many of them as I drove from place to place looking for any kind of nature obvious that day.
     Painted turtles are pretty and I enjoy seeing them whenever I can.  Their shells and scaled skin are mostly dark, which camouflages them.  But they also have striking red and yellow stripes on their necks and fore legs.  Yellow dominates their lower shells.  The upper shells of adults are about five inches long, and flat for easier slipping through water.
     Painted turtles are aquatic, commonly living in smaller impoundments and slower creeks.  They may be more common here today than ever in their life history because human-made impoundments seem ready-made for them.  They have adapted well to them.  And painted turtles move overland from pond to pond, as some impoundments become over-populated with them.   
     Painted turtles, like all living beings, are part of several food chains.  Youngsters consume a variety of invertebrates, as well as tadpoles, snails, carrion and other animal material.  Adults are more likely to eat aquatic plants.  And the main predators on younger turtles are snapping turtles, mink and great blue herons.  Skunks and raccoons dig up and eat their eggs. 
     Painted turtles are most handsome when quietly sunning themselves.  Their necks and heads are erect as they look around for possible danger.  And at the least hint of trouble, they flop into the water and swim to the bottom to hide. 
     These turtles breed early in summer.  Males have long toe nails on their front feet to caress females during courtship before mating.  And males have long tails that help in the process of breeding.  Females lay their half dozen or more eggs in soft soil near water.  Toward the end of summer, after a couple of months of incubating in the sun-warmed soil, the inch-long young hatch and enter the nearest body of water where they feed and grow until cold sets in and they are dormant through winter.  During warmer afternoons the next March, all painted turtles are active again and can be spotted.
     Painted turtles, and other kinds of turtles, except snapping turtles, are protected by law.  Capturing them for any reason is prohibited.
     Eastern painted turtles are inoffensive little critters that are lovely to see.  They make ponds and slow waterways more interesting.            

Stately Great Blues

     Great blue herons are large, stately birds, particularly in flight.  In shallow water and on land they are long-legged and have lengthy necks and beaks, making them about four and half feet tall.  In the air they appear really big, and startling, and vaguely resemble flying dinosaurs.  But they are also most majestic in flight, with their wings beating slowly, powerfully, necks drawn back in a tight S and long legs trailing behind for balance and steering.  Occasionally one in flight will utter a loud, hoarse call that might be a little frightening. 
     Although they are called blue, they really are gray, with a black stripe through each side of the face.  And in spring, their breeding plumage has  gray plumes on their backs and throats and black ones extending from the back of the head.    
     This heron species is common through most of North America, including here in the Middle Atlantic States.  And they have close relatives in Eurasia and Africa.  Most northern birds drift south for the winter where the water is still open to catch prey.  But some of them stay north all winter, if they can find open water where they can get food.  Birds do not migrate to escape cold, but to find reliable sources of food for the winter.      
     Great blues are predatory, eating large and small fish, frogs, crayfish, snakes, larger insects, mice and other critters in waterways, impoundments, wetlands, backyard goldfish ponds and meadows.
One day in March a few years ago, a great blue caught and ate all the goldfish in our suburban backyard pond.  We had to put a nylon net over our pond to protect their orange replacements.   
     Great blues hunt day and night, and individually, stalking slowly through shallow water to snare aquatic critters, moving forward carefully, step by step so as not to alarm potential prey into fleeing.  They swallow their victims whole and headfirst, which allows them to go down easier without fish scales getting caught in the birds' throats.  They dunk the mice they catch in water to slick the fur so they can swallow those rodents easier. 
     Between fishing forays, great blues perch on tree limbs near water, in cattail marshes and in harvested corn fields with stubble that must, to the herons, resemble cattails.  When resting in those habitats, they are hunched to resist weather and be less visible.
     Great blues raise young in colonies in stands of tall trees near water, including at least a few in the Mid-Atlantic States.  They begin nesting in March when deciduous trees are still bare, allowing us to see their large, bulky stick cradles.  Parent herons constantly shuttle food to their three or four young in each nursery until June when the offspring fledge their nests.
     Young and older great blues scatter across the countryside and visit any body of water that yields food to them through the rest of the summer and into the fall.  Sometimes they fight over hunting areas by flying aggressively at each other and calling raucously and repeatedly.
     Look for great blue herons in your area anytime of the year.  They are readily noticed many times, stately, and a bit startling, and much an intriguing part of the landscape wherever water exists.       
               

Adaptable Song Sparrows

     Song sparrows are plain, little birds that are big on adapting to a variety of habitats, the reason they are spread abundantly across North America, including in southeastern Pennsylvania.  These native birds inhabit thickets in cities, suburban areas, woodland edges, hedgerows between fields, and overgrown meadows, fields and stream sides.  Sometimes I see one or two song sparrows on a blacktop parking lot near weeds and shrubbery where they chase invertebrates, and seeds blowing in the wind. 
     Song sparrows are brown with black stripes and markings that camouflage them well in all their niches.  Each bird has a large, black spot in the middle of its chest that will identify it as to species.  And they readily come to bird feeders through the year, to the delight of bird watchers. 
     Males of this species are one of the first small, permanent resident birds to sing early in spring, as early as warm afternoons in the middle of February.  They sing lively songs from the tops of trees and shrubbery, lovely ditties that inspire many a human tired of winter and happy to see spring.  Song sparrow music is one of the first sure signs of the coming spring.
     So adaptable are they, song sparrows, as a species, could fill every niche left by extinct sparrows, if that happens.  Though most pairs of song sparrows nest low in protective shrubbery, some pairs hatch young on the ground under tall grass, the way grassland sparrows do.  Song sparrows could fill the niche of grassland sparrows, as well as other bush-nesting kinds. 
     But I think song sparrows are most beautiful and intriguing in shrubbery along inland waterways and impoundments.  And they have a lot of potential in that habitat, too.  This type of sparrow secretly slips along the edge of the water, as would inland kinds of sandpipers, but under sheltering shrubbery, to catch and eat a variety of invertebrates from the surfaces of the mud and water.  The sandpipers feed in open areas of mud flats and shorelines, thus lessoning competition with song sparrows for invertebrate food. 
     Song sparrows even wade in inch-deep water after food.  Longer legs, if the sparrows developed them, would help them catch more invertebrates in deeper water.  And with more minor changes in body structures and behaviors, they may become ever more sandpiper-like to take fuller advantage of that stream bank habitat to get food. 
     But these same individual song sparrows get invertebrates from plants along the shores, and seeds on those plants, and on the soil and mud.  And with one jump or flick of their wings they find shelter in shoreline thickets when danger threatens.  They really are birds of the shorelines of inland streams and impoundments, where protective thickets are present to hide from predators and inclement weather, and to raise young. 
     Unfortunately, song sparrows are sometimes victimized by female brown-headed cowbirds that lay an egg in each of several other birds' nurseries.  If the victims don't recognize the foil, they will raise the cowbird chicks with their own.
     Watch for song sparrows in thickets in suburbs, woodland edges, hedgerows and overgrown fields, pastures and stream sides through the year.  They are lovely, cheery birds that will make many a human heart sing.         

         

Scavenging Eagles

     On the morning of November 20, 2014, I was driving through farmland in Lancaster County, Pennsylvania when I saw what I thought was a hawk perched upright on a bare tree about a quarter of a mile away.  Through binoculars I noted the bird was an immature bald eagle.  And I saw a few other bald eagles near that first one.  I quickly thought of a way I could get closer to those birds for better looks, but still stay in my car so I wouldn't scare the eagles away.
     Arriving at the spot where the eagles were perched in a line of several trees, I saw hundreds of wintering American crows down from their breeding territories in Canadian forests in those same trees, in the air and on the ground, many of them cawing raucously at once.  A few turkey vultures were on the ground and other turkey vultures and a few black vultures were in the air gracefully soaring toward the ones on the ground.  I noticed, too, that several red-tailed hawks were in the same trees the eagles were perching on.  I counted 12 red-tails and 30 bald eagles in those trees.  About half those eagles were immature with brown plumages all over.  But all the eagles were magnificent and exciting to see, especially in Lancaster County cropland.  And all these birds together created an enjoyable show. 
     In the process of watching the hawks and eagles, I noticed that some of both kinds had risen from the ground or landed on it out of sight on the other side of a small rise.  I had the idea that 12 and 30 were conservative numbers. 
     The draw for this post-breeding, wintering gathering of crows, vultures, red-tails and eagles was a nearby poultry farm where thousands of domestic birds are raised for meat.  But some die of disease or trampling and are disposed of in fields.  There they are an abundant food for a variety of birds and scavenging mammals, such as foxes and raccoons.            
     There are bigger concentrations of wintering bald eagles in North America than this one, including several in Alaska, along the Mississippi River and lower Susquehanna River, for example.  But this is the biggest inland gathering of balds I had ever seen or heard about, which is their greatest excitement in this county.
     Bald eagles have increased their numbers greatly through much of North America because of the ban on using DDT in fields, their being protected by law, and their adapting to human-made habitats that are less than ideal.  Scavenging dead farm animals is one of those adaptations the eagles and other kinds of larger birds have advanced for their survival.
     Most people think of bald eagles as birds of large bodies of water where they catch and scavenge fish, ducks and other creatures.  And many of them do.  But many eagles today regularly get food inland, particularly on fields.  Those pioneering eagles, in time, may create a new species, one dependent on inland creatures.
     Nature is always beautiful and interesting, no matter where it is found.  And critters that adapt to human-made habitats and activities are the most intriguing of all.