Wednesday, January 29, 2014

The Great Arctic Migration

The National Wildlife Refuge System plays a critical role in providing wintering grounds and staging areas for the Great Arctic Migrations. Before I go any further, I must say that I love winter for this very reason. I love all things Arctic and when the Arctic can come to me, so much the better! If you are not into cold weather then this is not the blog post for you. Stop reading now.  But if you love it as much as I do, carry on...

Ice wall at the high tide line.
Coastal Delaware River at Broadkill Beach near Primehook NWR

National Wildlife Refuges are some of my most favorite places to visit, no matter where I am in the country. Those of us lucky enough to live beneath the immense Atlantic Flyway have dozens of beautiful wildlife refuges across coastal areas in NY, NJ, DE, MD, and VA to visit. Considering the   Arctic nearly empties of its birds for the long polar winter, and that almost a third of these great migratory waves of ducks, swans, geese, loons, shorebirds, waders, passerines, and raptors use the Atlantic Flyway in their travels, well - we're in business!

Sharp polar winds raise the neck feathers on a watchful snow goose while its flock mates (blue morph included).

Most Arctic birds inhabit wetlands, finding food, claiming breeding territory, and enjoying a measure of safety in the vast northern system of marshes, ponds, lakes, bogs, and coastal regions. Come the brutal cold of winter, however, ice freezes up and food is inaccessible. Land hunters such as fox, wolf, bear, mink, fisher, and in the southern taiga, lynx take to the frozen lakes to hunt. Lush aquatic plants and seed-bearing grasses are sealed away by ice and cold and darkness. It's time to go!

The Great Migrations begin as early as late August for some species, and is complete in the Mid-Atlantic area by November.  Some Arctic migrants stop-over here and continue moving south, with a few species of terns, sandpipers, and sanderlings traveling incredible distances to South America!

Emily scans Shearness Pond at Bombay Hook DE for Arctic visitors. 


The story of the National Refuge System is one of great pride for American conservation. Avian species that only a few generations ago were in danger of extinction are now abundant and growing in population. Due in no small part to the extensive system of managed and protected refuges, we can now look out over our winter coastal landscape and enjoy the sights and sounds of great flocks of birds.


Tundra-like landscapes with open water leads and abundant food attract millions of arctic birds.



It takes a hardy naturalist to venture out in Arctic-like conditions, and this year has served up plenty of single-digit, brutally cold days and nights, but how exciting that our bitter winter is the perfect weather for exciting polar events! This year an amazing irruption of snowy owls swept into our region and (for the bundled and determined birders of the Mid-Atlantic) sightings were plentiful. Project SNOWstorm rapidly deployed a successful social media fundraising campaign  to purchase dozens of owl-sized transponders and within weeks their goal was reached - and exceeded! Many snowies were trapped from Wisconsin to New Jersey, and fitted with solar-powered GPS transponders. Donors and citizen scientists are able to follow their movements on the website, as the owls 'check-in.'  Following the owls will teach us much about their hunting routines and preferences, where they rest and when  they are active, and above all, give us a window into the lives of these creatures for which we know surprisingly very little. Check out Project SNOWstorm at http://www.projectsnowstorm.org/


One of several  Snowy Owls we saw in one day along the Delaware Coast. Primehook NWR and Broadkill Beach, DE.


What's an irruption? 
This year's impressive snowy owl irruption may be the result of a large number of young owls being hatched and surviving the short Arctic summer, due in part to the high population of lemmings this year. Like many prey animals, lemming populations cycle up and down over years and decades.  Arctic biologists this summer observed the owl's ground nests ringed with dead lemmings indicating the top of the cycle. Low populations of lemmings in the down cycle often resulting in no breeding at all for snowies in some years. It is not uncommon to have occasional snowy owl sightings during the Mid-Atlantic coastal winter, but this year has been spectacular!

 
The horned lark population swells with Arctic flocks working across plains, fields, and pastures. Common at all refuges where food plots, grain fields, and meadows are maintained for winter foraging.

A family group of tundra swans  rest in the winter sun at Bombay Hook NWR, DE.
Without the safety of a large flock, this group is using the open expanse of ice
to provide a sight-line for approaching predators.

How do they 'know' to come south?
Some wonder if the birds "knew" we were in for a harsh winter. Arctic birds are sensitive to three environmental cues: food supply, barometric pressures (foretelling changes in weather patterns), and length of day (photoperiod). In response to a combination of cues, some species migrate sooner or later than others. Fall waterfowl migrations, spectacular for us, are generally not as risky as the return trip. Come spring timing is critical. It is not unusual for entire breeding grounds, crowded with returning birds, to experience the cruelty of a lingering winter. Nests on low patches of ground are easily flooded, and sitting birds on eggs are at the mercy of ground hunters when ice persists. Most arctic species hatch precocial young: babies that are ready to run and hide as soon as they hatch. But if hunters find an entire nest of eggs unguarded, the whole clutch will be destroyed.   
Roger and Donna West with my daughter Emily celebrate a fantastic owling day!

    




I keep a few Arctic field guides and natural history books (well, maybe more than a few) on my shelves at home. In winter, they are all off the shelf! These are two I really like, and on snow days and rainy weekends I re-read them. Someday, I'll make it the Arctic. But until then I am enjoying every day the Arctic comes to me! 



Pielou, E.C. (1994) A Naturalist's Guide to the Arctic. University of Chicago.

Sale, R. (2006) A Complete Guide to Arctic Wildlife. Firefly Books, Buffalo, NY.

This post is dedicated to the snowy owl known as 'Philly' who 'checked out' today at Philadelphia International Airport. Unfortunately, the arctic-like landscapes of airports attract young snowy owls, unfamiliar with planes and traffic, and many, like Philly, are killed before they can be safely relocated. Rest in the Great Tundra Above, young owl.

Tuesday, January 21, 2014

'Just" A Walk In the Woods

There can never be 'just' a walk in the woods! Local trails, no matter how familiar, always hold surprises. In the Piedmont region, where the Eastern continental landmass tilts seaward from the Appalachian Mountains to the Atlantic Ocean, creeks and rivers carve their deep paths down through millions of years of rock and debris, eroding and shaping the rolling and even steep landscapes we know close-to-home. For many residents of the Mid-Atlantic, the Piedmont geophysical region is familiar, yet often unexplored and under-appreciated ground. 


An outcrop moss and fern community growing on blue-gray Wissahickon schist.
















Aspects of the landscape that we describe as 'just woods' in winter reveals itself as a complex tapestry of color, timber structure, and flow of geological forms that invites exploration. Ridges, outcrops, ravines, tumbling creeks, and yawning valleys are filled with light, color, and surprises on a winter's walk. Local parks and greenways such as Philadelphia's Wissahickon Gorge and Valley Trail are fascinating trails bisecting one of our oldest Eastern cities (see Friends of the Wissahickon www.fow.org ) - a local trail for 1.5 million residents! Come summer these swaths of urban wooded valley and ridge will be cloaked in green, hidden by foliage for everyone except the hiker beneath its canopy.

Pale green trunks of American beech contrast with the red-leaf carpet of
leaves in this typical ravine stream of the Piedmont. Fagus grandifloria.

My local trails are embedded in the agricultural landscapes of South Central Pennsylvania and northern Maryland. I am lucky to count the Appalachian Trail, the Mason Dixon and Conestoga Trails as my local favorites. These are difficult ravine and ridge trails, studded with outcrops, and rocky underfoot. Winding across public and private lands, these trails rise frequently to the Piedmont tablelands where cultivated fields and pastures border the forest. The brushy edges of forest and field come alive with winter flocks, cohorts of several bird species that move and forage together through cover.  Sometimes it's easy to take for granted the common birds that form these cohorts. Last week while hiking a favorite trail in Maryland, an out-of-town visitor from Japan was nearly bowled over by his first cardinal sighting!


Cardinal eating seeds along a forest edge.  Nearby a Japanese tourist was jumping up and down, so excited by his first cardinal sighting! All birders, no matter their home country, do a little 'life bird' dance - and this young man
really had the moves!

A favorite competition between my birding friends and family is winter hawk watching by car and by foot. Perched on highway light posts, fences, silos, oak limbs, and winter-bare treetops along edges and roadsides, we call out our sightings with (hopefully) correct identifications. The buteos, the biggest hawks, are easiest to identify and a good place to start for the novice birder in winter.  No matter how many times you spot a big burly red-tailed hawk, his chest shining bright in the low winter sun, it's always a thrill. Especially if you call it before your companion! Walking the familiar woods, keep your eyes open for red-shouldered hawks, sharp-shinned hawks, and coopers hawks that work the wooded edges for songbirds and ground birds.

Red-shouldered hawk, the brightest red of the buteo hawks.
Blackwater National Wildlife Refuge, near Cambridge, MD

The breast of the Mockingbird reflects soft earth browns as it perches low
in brushy areas during winter months. Come spring he'll perch high and
sing his breeding territory declarations from favorite  treetops.

In winter the Mockingbird is quiet but very active in his cold weather territory. His patch is guarded ground  for the many food resources he has claimed, from berry bushes and brush piles to old orchard trees with a bit of old hanging fruit still on the limb.  A three mile hike along the Ridge Trail at Susquehanna, one of the jewels of Maryland State Parks, revealed over a dozen mockers close to the footpath holding their berry-filled winter yards within very defined boundaries. These yards are declared in early autumn with exact boundaries established by much flying from perch to perch, loud repetitions of their collected songs (each given three times!) and sometimes, a hopping, fluttering face-off with a neighboring patch owner. By winter all is settled, but still the boundaries are flown and inspected throughout the day. 


A shaggy River Birch with its red-brown peeling bark. Betula nigra.


A winter hike over familiar ground gives us a wonderful opportunity to look for identifiers of tree species in our local parks and trails. Bud structure, tree form, and bark texture and color are intriguing ways to learn the familiar trees of our yards, paths, parks, and streets. Donald Peattie uses rich language to describe the types of bark found among the Mid-Atantlic forest. For the persimmon - "deeply divided into innumerable square plates." American Holly - "roughened by little warts." Black cherry - "aromatic, broken into irregular scaly plates divided by braided fissures." Paper birch - "orange-brown, peeling, papery thin layers marked by raised lenticels." What a creative exercise for the trail-bound poet.


Fruit of the Sycamore dangles like golden-brown ornaments. Platanus occidentalis.

When I hike local trails, especially with students and grandchildren, I chose a theme that will have us looking in all the usual places for hiding-in-plain-sight surprises. We've hunted for Christmas ornaments, eating and garden utensils, and listened for anthems. We've taken watercolor paints and crayons (in the 64 pack of course!) to draw or paint in our journals with hues that most closely match items in nature.  On one well-remembered local hike I took a book of Mary Oliver poems to read at each bench along a town path.

For me, when I am short on time but yearning to get out for a walk in the winter woods, I take the camera and one lens: a macro, telephoto, wide-angle, or standard. I purposely limit my shots to what the lens will allow. With each familiar trail I can capture unique views of  "just a walk in the woods."
I hope you enjoy the results throughout this blog!

Thursday, January 16, 2014

Arctic Comes Knocking

I am a winter person. It's my favorite time of year for many reasons, but mainly I love it because so few people are out, especially on the coldest days. Having spent some time in northern New England, tough winters taught me that it's really mind over matter, with a lot of preparation! So when the much talked-about Arctic Vortex spun wildly south this week, setting all-time low temperature records in much of the East, what's a winter naturalist to do but go out and enjoy it!


The night before the arctic system arrived, a beautiful fog lifted from the
melting snow as a warm rain fell. The next morning everything was
encased in ice as the cold air arrived.
Joe Pye in ice.


A killdeer flies over the frozen cove at Swan Harbor Farm
on the Chesapeake Bay.

A seep flash froze overnight. Ice patterns resemble the shapes
of the leaves that frame the small springhead.
Fractals?

Low winter light illuminates the underside of a yellow-shafted
flicker's wing. Birds seemed unaffected by the cold blast.

Sweet gum seed pod frozen into cove ice.
Swan Harbor Farm.

A day of rain washed away eight inches of snow, but when the arctic air mass
arrived, the few drifts and banks that remained held tight to their treasures.
Tulip poplar leaf.



Mid-Winter White Throats

This week marked the meteorological mid-point of winter. Forty-five days of winter under our belts, and forty-five days ahead of us. And now it can get really interesting! At mid-point, the observant naturalist will detect signs that spring is on its way! With deciduous trees and understory winter-bare, marshes bent low by winds and rain, and farm fields at rest, the cold-weather naturalist is sure to see change-a-coming. But it's in the sound of early spring's arriving that I find most fun, especially with kids. Every now and then, an ambitious songster belts out a springtime song of love...

White-throated sparrow, Zonotrichia albicollis

Hiking at a local park this week, I was able to identify two passerine (song bird) loudly calling songs usually heard in late winter and throughout the spring. A tufted titmouse cried "Peter! Peter! Peter!" from a brushy edge. A common winter sparrow for the Mid-Atlantic, the white-throated sparrow, sang "Oh, Sweet Can-aaa-daaa!" from a prominent branch. The titmouse was invisible in his gray coat against the gray brush, but the white-throat, his bright yellow lores, smart black eye stripe, and snappy white bib stood out boldly against the dull wet woods. In a few weeks our winter white-throats will be migrating to Canada and the Northeast. Hearing his breeding call in mid-winter was a real treat!


After observing the foraging behavior of the white-throated sparrow,
look carefully for its 'walking' tracks in snow.
Octoraro Reservoir Gamelands, Lancaster County PA

The white-throated sparrow is a great bird for kids to identify on mid-winter hikes. There are plenty around, especially in brushy patches and yards, fun to follow and stalk. Stalking can be done with any species of sparrow, but white-throats seem to enjoy it, keeping just ahead of you, popping up to make sure you are still sneaking along behind them.

Peeking through branches and limbs, young naturalists will learn the art of still hunting: standing in one place long enough for sparrows not to mind your presence. With binoculars, kids can easily observe the field marks of these busy seed-eating birds as they root through grasses and leaves.

If the ground is snowy, be sure to examine the tracks of the white-throated sparrows once the birds have moved on to the next patch. As a ground foraging bird it has a walking track, rather than the side-by-side hopping track of perching birds.

Examine the foraging site for what they were eating. White-throats enjoy the fleshy parts of small fruits and berries, leaving skins and hard seeds for other foragers. A handful of raisins or cranberries thrown on the ground around a feeding station or placed near your still-hunting patch will attract white throats in no time. A good birding friend of mine can lure them to eat raisins out of his hand if he sits still on the ground.

Sparrows can be challenging birds to identify, but in winter our choices in this region are limited to just a few species. Learning a few sparrows well during the winter season when you know to expect and see them often, can help with more difficult identifications later on.

A really nice bird tracking book comes in handy on snowy days:

Elbroch M. and E. Marks (2001) Bird Tracks and Sign: A Guide to North American Species.  Stackpole Books.




Saturday, January 4, 2014

Donald Peattie: Naturalist Writer

I grew up with books about farming, natural history, and conservation biography. I can recall many loud and boisterous family gatherings from which I would quietly slip away with a favorite book to immerse myself in the topic and the writing. A nature writer for whom I credit with my appreciation for the power and beauty of nature prose is Donald Peattie.

I often think that the within the larger thicket of our personal environment and societal times, our paths are hewn by facing our troubles head on and in doing so, we discover our gifts. Such was the story of Don Peattie who, like many writers of the early 1900s, moved to Europe to discover his muse, but returned to the States penniless and disillusioned smack in the middle of the Great Depression.



Trying to support a family with bit jobs writing brochures, he began to keep a nature observation journal to keep his spirits up day-to-day. Through his journaling he found his calling and a great passion for nature writing. An Almanac for Moderns was the published collection of short essays based upon this journal and it was the first book of Peattie's that I picked up at the tender age of ten. It was already dog-eared and worn, chosen from my mother's bookshelf during one especially loud Christmas visit. I crawled under her desk and began to read. All the dinner clamor and noise seemed to melt away with "Beauty is excrescence, superabundance, random ebullience, and sheer delightful waste to be enjoyed in its own right." What? I remember thinking. People are allowed to write like this? About nature? In a their journal?

After reading An Almanac for Moderns I began to carry my nature journal with me everywhere,
even if the journal itself was bulky and heavy. Most got wet, torn, singed
stained, smudged, or damaged, and that too is part of the tale.
Nature Journal 2002.
Peattie was a meticulous naturalist and botanist. But he knew that science only generated more questions than it could answer. Through his natural history writing and his many, many books, he used prose to blend natural mysteries with the fascinating information that science had discovered about our natural world. In his monumental works on the natural history of trees he pours out his love for the American woods and imbibes every essay, written for each species, with scientific fact, history, and humor. His status as one of the most influential naturalists of his day is not lost on today's reader, for he continues to inspire and motivate us to have direct experiences with all aspects of nature and to reflect deeply about these experiences.


Peattie spent many years in the Mid-Atlantic and Appalachian regions, working as a botanist for the USDA and then working as a long-running nature columnist for the Washington Star. He explored the mountains, rivers, fields, farms, and parks throughout the region, making careful observations about all aspects of nature, especially the trees. He was especially attracted to the area's colonial history and blended much of his nature writing with the history of Mid-Atlantic landscapes and human interactions with nature based on colonial industry, trades, and farming. He thought George Washington too much an Englishman, but Tom Jefferson suited him just fine. Studying Jefferson's writing revealed a deep love for the American landscape and passion for progressive farming. Peattie defined Jefferson as the ideal American naturalist and arborist.

For this post I thought it would be fitting to share some of my favorite tree portraits accompanied by Peattie's eloquent and humorous descriptions for them as found in the Natural History of Trees of Eastern and Central North America:

Witch Hazel (Hamamelis virginana)
"They eject their shiny, hard, black seeds with violence; the tree which seldom grows more than twenty feet high, can send its seeds much further...thus the wintery-blooming Witch Hazel, of ancient geologic lineage, is still today well able to maintain itself."


Bald cypress (Taxodium distichum)
"A name is only an open door to knowledge; beyond lie the green ways of growing and too, all that makes a tree most interesting and important to man. Nowhere else in the world have trees so profoundly influenced the migrations, the destinies and the lives of human beings."


Persimmon (Diospyros virginiana)
"No matter how we humans improve the breed, or cook the fruit, the persimmon will never mean to us what it does to the lives of the wild animals. It is eaten by birds, notably the popular bobwhite, by the half-wild hogs that rule the Ozarks, by flying squirrels and foxes, by raccoons and skunks and white-tailed deer, and above all by the opossum."



Red Cedar (Juniperus virginiana)
"So easy was [red cedar] to split with the frow and to smooth with the plane that it could be worked even by people as woefully ill-prepared for wilderness life as the theologian-tradesmen and overdressed gold hunters who first sought our shores."



Peattie, Donald C. (1966) A Natural History of Trees of Eastern and Central North America. Houghton Mifflin Company, Boston.

Peattie, Donald C. (1935) An Almanac for Moderns. (2013) Trinity University Press.

Chicago Wilderness Magazine maintains an online archive of the works of Donald Peattie and his wife Louise Redfield, also a writer.
http://www.chicagowilderness.org/CW_Archives/issues/fall2000/peattieresources.html







Friday, January 3, 2014

American Beech

"I frequently tramped eight or ten miles through the deepest snow to keep an appointment with a beech-tree, or a yellow birch, or an old acquaintance among the pines."
- Henry David Thoreau


A grand old American beech competes for a photographer's attention with nearby sycamores
on the grounds of the N.C. Wyeth home and studio. What a painting this would make!
Chadds Ford, PA
One of my favorite trees, and one that puts on a beautiful show in every season, especially winter, is the American Beech, Fagus grandifloria. Hiking with children, the beech should be one of the first they can easily identify in any season. Well-kept trails make hiking through a beech forest an easy undertaking in many Maryland State Parks, and there are beautiful stands to be seen in community parks and greenways throughout the region. Walking through a pure stand at sunset can be nearly magical.


Framed by sweetgum (Liquidamber styraciflua) young American beech form a root sprout
stand in the rich soils of this lowland forest in Perryville, Cecil County, MD
 
The American beech is considered one of the dominant Eastern forest trees, that often shares climax status with maples, oaks, and gum wherever soils are rich. Grand old trees will buttress out from their base with dozens of large shallow roots. Root systems will spread underground as far as the tree is tall, creating a network of enmeshed roots with other trees. As enmeshed roots from several trees can form biological bonds that transfer nutrients, water, and sugars. Many beech will root-sprout and send up root suckers by the dozens. A good 'beech-gap' of root-sprouted young trees is the primary means of reproduction in most stands. These young trees usually hold tight to their leaves throughout the winter, an easy marker for identifying this species. Look for the parent tree in the center of the 'gap.'



A beautiful array of shallow roots spread powerfully
through the moist, rich soil of a lowland forest.
Chadds Ford, PA
Donald Peattie, author of the classic A Natural History of Trees of Eastern and Central North America (1948) showers the American beech with praise, claiming it as one of the grandest of all our forest trees. He describes the bark as 'tight fitting' clear gray and a tree of historic importance to the colonists and settlers who found it welcoming and familiar as it is also found in Europe (Fagus sylvatica). To read his tribute to the beech is to understand how beloved this species was, and I hope will continue to be.

A Mid-Atlantic naturalist should have
this classic natural history book on
their library shelf!
   
What gives this tree such beauty is also its weakness. The thin bark of the beech makes it susceptible to deep cold, fire, and disease. Most obvious in a well-travelled beech woods, the quality of  beech bark  seems to attract all manner of human inscribers, declaring their love or expounding on topics of the day.  One old stand of beech in the Perryville Community Park in Cecil County MD contains dozens of massive beech trees carved round and round, from the ground level to as high as a man can reach with wild rantings of a  combat veteran who was surely a resident of the nearby veteran's hospital. This resident appears to have been a Korean War soldier and found the thin barked beech worthy of extensive time carving long missives against the war. It is heartbreaking to come across these trees and I when I visit this area, I always stop to say a prayer for this broken soul. I wonder who he was, where he fought, what he saw, and where he called home.

A reminder to Seize the Day, along the Land of Promise Trail in
Susquehanna State Park, Havre de Grace, MD
 
Tom Wessels, one of my professors in grad school a few years ago, describes in his book Reading The Forested Landscape (1997) how the thin-barked beech has become victim to not only carving and defacing, but to an introduced invasive pest that arrived with loads of imported beech from Europe in the 1890s. "What?! Imported wood?" you say.

By the end of the Civil War, much of the Eastern states had been deforested, which is hard to believe now as forests cover a great portion of our region. Wood was regularly imported and with it came all manner of insect and fungal pests. Defenseless against bark-piercing insects, the American beech fell victim to an introduced scale insect and an opportunistic fungus, Nectria. The insect is the carrier of the fungus, and whether spread by the sharp incisors of the bug or by the blade of a pocket knife, the fungus can quickly infect the tree and cause massive damage to the cambium layer. Within months the bark of the infected beech will blacken and begin to blister and crack. If the infection should girdle the tree, it will soon die. The disease continues to spread throughout our region.

A good video from Cornell Cooperative Extension explains the disease:

http://video.about.com/forestry/What-Is-Beech-Bark-Disease-.htm

A good reason to teach our children never to carve into a tree. Wounds in bark, especially in thin-skinned trees like beech, can bring a world of trouble.



With my back to the parent tree, a 'beech gap' of root-sucker sprouts
surrounds me with golden winter-held leaves.
Perryville Community Park, Cecil County, MD

I have many found memories of gathering beechnuts with my Great Uncle Mac and Aunt Virginia who would happily collect copious amounts of beechnuts in their fall foraging, hours on end. Shelled and boiled or roasted, they were delicious, and Mac would grind a nice coffee with the aromatic nuts. The deep distinct smell of beechnut coffee carried a scent of rich woodlands on those cold, crisp collecting days. I loved how the way the prickly shells stuck to my little red gloves.
 
A common forest floor companion in the beech woods is trailing arbutus.
Look carefully to spot the prickly beech nut lying in and around other tree seeds.
Susquehanna State Park, Havre de Grace, MD

The beechnut can be found in profusion in the autumn months when the tree's toothed simple leaves turn brilliant yellow. These nuts are critical food for forest animals, and are a preferred forage crop for bears, deer, turkey, and  small mammals who, like blue jays and woodpeckers, will cache them in secret niches and holes. The nuts were preferred forage for the masses of passenger pigeons that darkened our skies on autumn migrations. Limbs of the great trees would crash to the ground with the weight of the birds in their night roosts. What a thrill that must have been to early naturalists to see these gatherings and flights, though the passenger pigeon is gone now because of market hunting and greed. I wonder what effect the loss of the bird had on the tree?


John James Audubon

I dismounted, seated myself on an eminence, and began to mark with my pencil, making a dot for every flock that passed. In a short time, finding the task which I had undertaken impracticable as the birds poured in in countless multitudes, I rose, and counting the dots then put down, found that 163 had been made in twenty-one minutes. I traveled on, and still met more the farther I proceeded. The air was literally filled with Pigeons; the light of noon-day was obscured as by an eclipse; the dung fell in spots, not unlike melting flakes of snow; and the continued buzz of wings had a tendency to lull my senses to repose... Before sunset I reached Louisville, distance from Hardensburgh fifty-five miles. The Pigeons were still passing in undiminished numbers, and continued to do so for three days in succession.
- John James Audubon,  


Little, Elbert L. (1980) The Audubon Society Field Guide to North American Trees. Alfred A. Knopf, New York.  (This is an old field guide that I stuff into my pack when hiking through forests. Though there are better field guides with different, maybe better,  identification systems, this old book has served me very well!)

Peattie, Donald (1991) A Natural History of Trees of Eastern and Central North America. Houghton Mifflin Company, Boston. (Too big and heavy to take along! Leave this for evening reading at home.)

Wessels, Tom (2005) Reading the Forested Landscape: A Natural History of New England. Countryman Press.  (Though focused on northern woodlands, this book suits our region well as many of the events and species discussed are shared with much of the Mid-Atlantic.)