The Glory Days of September

After the slow, hot days of summer, September with its often cooler, drier days is a welcome relief.

A chestnut-sided warbler in the fall

A chestnut-sided warbler in the fall (Photo by Kaaren Perry on Flickr, Creative Commons license)

Most of the fair-weather songbirds are still here, but some are already on the move by the beginning of the month. I looked out on a wet day in early September and caught a flush of birds taking shelter in the juniper tree beside my study window.

I easily identified a black-and-white warbler, black-throated green warbler, blue-headed vireo, two red-eyed vireos and a black-capped chickadee. But one bird stumped me. It turned out to be a first fall female chestnut-sided warbler, according to my Peterson bird guide, what he once called one of the “confusing fall warblers,” those that no longer sport the bright colors of spring. They are mostly the males but also include females and the young of the year.

In addition, with no need to attract mates, most male songbirds no longer sing which makes identifying them even more challenging. An exception is the common yellowthroat that is still singing his distinctive “witchedy, witchedy” song in mid-September. He also retains his black mask but neither the olive-brown female nor their young—all with yellow throats and breasts—have masks.

A yellow-rumped warbler in the fall

A yellow-rumped warbler in the fall (Photo by Ryan Mandelbaum on Flickr, Creative Commons license)

I’m not a keen birder, like two of my sons, so I am content to leave the sorting of the puzzling birds to them. Still, I appreciate yellow-rumped warblers that visit our First Field in flocks. They may be mostly brown and white in fall but both sexes and the immatures always sport bright yellow rumps.

Ovenbirds too remain the same, looking much like thrushes except for the orange patch lined in black atop their heads. In September the adult birds have left for their wintering grounds in Mexico, Central America or the West Indies, and their offspring have to manage on their own. They are much bolder than their parents and continue walking on the woods floor when I encounter them.

A chipmunk in a Pennsylvania forest

A chipmunk in a Pennsylvania forest (Photo by Brian Henderson on Flickr, Creative Commons license)

One beautiful September day I sat inside our three-acre deer exclosure on Turtle Bench watching chipmunks, including one that had a hole at the base of a witch hazel tree a couple feet from the bench. But first one young ovenbird, followed by a second one, walked past and poked on and under the leaves searching for food. The first one ranged back and forth and then wandered off but the second ovenbird stayed near the bench probing at dead leaves. The youngster leaped up several times to snatch insects from a red oak seedling, but eventually it also wandered away. And all the while numerous chipmunks chased and called, ignoring me just as the ovenbirds had.

I’m never happier than when I can watch wildlife unaware of or uncaring of my presence. The easiest mammals to watch on our mountain are porcupines. One September morning I was almost to the top of our First Field Trail when I spotted a large, probably male, porcupine heading my way. I moved to the side of the mossy trail as he stumped past. Then I decided to follow him.

He sniffed at ferns as he passed them and clambered over or under fallen trees. He seemed bent on moving rapidly straight into the upper end of the exclosure fence. Since I was several hundred feet from one of the three gates into the exclosure, I paralleled him on the trail outside.

Occasionally, he stopped and sniffed but kept walking fast. He reached the Turtle Bench area where I had been sitting only moments before. I carefully opened the gate and eased my way into the exclosure. He sniffed around the base of our 1812 red oak tree and then headed directly toward me. I moved aside as quietly as I could, but the dried leaves crunched beneath my feet and he was alerted. He looked up, sniffed in my direction, and I could hear the clattering of his teeth as he fanned his quill-filled tail. Still, I didn’t move and he made several attempts to come toward me, clearly wanting to go through the gate area and back to the First Field Trail. Finally, he gave up, turned, and walked down through the middle of the exclosure.

A porcupine on the forest floor

A porcupine on the forest floor (Photo by Steven Kersting on Flickr, Creative Commons license)

I let him get ahead of me before quietly following. He circled a few trees sniffing and then sniffed and reared up on his hind legs like a woodchuck. Again he started toward me, but then turned and disappeared into a large area of horse balm and spotted touch-me-nots and flushed a young ovenbird. I assumed the porcupine either hid there until I left or went out through the fence.

Even though he knew something—a possible threat—was nearby, he didn’t climb a tree to escape as porcupines usually do. At 20 feet away, I had heard his warning teeth clacking. He seemed to have excellent hearing and sense of smell, but he showed no interest in food like a porcupine I had watched in the summer carefully picking and eating Pennsylvania smartweed from a large patch of stiltgrass.

I decided he might have been tracking a pre-estrous female. According to Uldis Roze, in his book The North American Porcupine, mid-September to mid-October is the mating time for porcupines, and males begin by following odor plumes sent out by pre-estrous females. Since females are only in heat 8-to-12 hours a year, males like to be on site several days in advance, guarding a female by climbing into her tree and waiting on a lower branch, sniffing the air or her branch to see if she is ready to accept him. The males often wait several days and sometimes compete with other males for her acceptance. The porcupine I followed did rub his head at the base of several large trees leaving his own scent I assumed, although Roze didn’t mention this action in his book.

Monarch butterflies on goldenrod

Monarch butterflies on goldenrod (Photo by Rachel Laubhan / USFWS on Flickr, Creative Commons license)

Once I lost sight of the porcupine, I walked over to our 37-acre First Field, which was covered with goldenrod and asters. Dozens of monarch butterflies nectared on the wildflowers along with pearl crescents, smaller butterflies than the monarchs but also colored orange and brown. Unlike the monarch caterpillars, which fed on our common milkweed leaves in mid-summer, the pearl crescents’ food plants are asters.

We have several aster species in our woods as well as in the field. Aster means “star,” hence the words “astronomy” and “astronaut.” In September the Ojibwa Indians smoked asters in their pipes to attract deer and other game. I’m not sure how that worked, but I suppose archery hunters could try it!

Asters, with 55 species in the northeast and goldenrod with 50 are true native wildflowers. The Chippewas called tall goldenrod (Solidago altissima), the last of the five species to bloom in our field, “squirrel tail” because they grow so tall.

A red admiral butterfly on goldenrod

A red admiral butterfly on goldenrod (Photo by BBureau on Flickr, Creative Commons license)

Our field of gold draws other migrating butterflies in addition to monarchs. All three are in the genus Vanessa. Most notable are red admirals, which are black with orange and white markings and migrate south for the winter. So too do the orange, black and white, painted and American ladies, all of which also nectar on the goldenrod and asters.

Green darner dragonflies hawk insects above the field on their way south. Sometimes near dusk I have counted as many as 50 hunting on our barn bank.

September is the last month to find blooming wildflowers. At the base of First Field is a wet area that is excellent for turtleheads. Their genus name Chelone is Greek for “tortoise” because their pink and white flowers look like the heads of turtles. Orange and black Baltimore checkerspot butterflies lay their eggs only on turtlehead leaves+, and those butterflies are usually not found more than 10 yards from a patch of turtleheads, as I’ve discovered. The flowers are pollinated by large bees strong enough to push their way into the turtleheads’ one-to-two-inch-long flower tubes to obtain nectar at the bases of the flowers.

A female hummingbird perched among some jewelweed

A female hummingbird perched among some jewelweed (Photo in memoriam: Steve Burt on Flickr, Creative Commons license)

The spotted jewelweeds, also known as touch-me-nots, in the wetland section of our exclosure, have orange-spotted, cornucopia-shaped flowers designed to be pollinated solely by hummingbirds. Their long bills pick up pollen grains from inside the top front of one flower and drop them on the inside top of the next flower when they probe for the nectar. I spend hours there watching as ruby-throated hummingbirds zip from one jewelweed to another. I have also seen bees stealing nectar from jewelweed by biting through the backs of these flowers instead of trying to push their way through the blossoms.

Near the end of September, most of the wildflowers are fading, but by then the witch hazel and black birch understory have turned golden and the black gum trees are red, gold, orange, or pink, giving those of us who hike or hunt in the September woods a special early showing of autumn color that almost makes up for the loss of wildflowers and migrating songbirds, butterflies and dragonflies.

 

Food for Wildlife

After three lean years, our oak trees finally produced a bumper crop of acorns last September. Forewarned by hordes of blue jays screaming from the treetops as they plucked ripe acorns from the oaks, I had to be careful on our steep trails not to slide on the fallen nuts that were more hazardous than marbles.

grey squirrel

Grey squirrel eating an acorn (Juraj Patekar image on Flickr, Creative Commons license)

Still, not every section of forested Pennsylvania had a good acorn crop, despite predictions from folks that should know better. Dr. Marc Abrams, a forestry professor at Penn State says there’s “no way to predict it,” calling a heavy mast year “one of the amazing mysteries in nature that we still do not have a handle on.”

Dr. Warren G. Abrahamson, a Bucknell University professor who conducted a long term study of acorn production from 1969 to 1996 with Jim Layne of the Archbald Biological Station in Florida, agrees, although he says that “the production of acorns definitely is not forecasting but hind casting the weather.” In their September 2003 report of their work they claimed that the size of the acorn crop each year is partly controlled by precipitation which affects acorns during different stages of development in prior years.

Other experts think that the group behavior of masting trees called synchrony most likely depends in part on the temperature during pollination in late April or May. Since oaks are wind-pollinated, meaning the wind must transfer pollen from staminate (male) to pistillate (female) flowers, a period of rain might disrupt the process.

For instance, a cold, wet spring in 2012 affected red oak production in 2013 because all the oaks in the black oak group (those with pointed lobes on their leaves) take two years to mature. Those in the white oak group (those with smooth lobes on their leaves) take only a year and would be affected by a late spring frost during pollination.

Still others believe that synchrony occurs as a way to outsmart nut predators by producing more nuts than the predators can eat, ensuring that at least some nuts will grow into trees. But whatever the causes, it is cyclic and occurs every three to five years.

On our dry mountaintop we have mostly chestnut oaks with an occasional white oak in the white oak group. Deer prefer these tastier acorns and squirrels eat them almost immediately because they spoil more quickly than those in the black oak group, which include scrub, black, northern red, and scarlet oaks here. Those acorns the squirrels store.

hickory nut

Hickory nuts form 10 to 25 percent of a squirrel’s diet in a good year (image by Peppysis on Flickr, Creative Commons license)

Acorns are not the only hard mast fruit. Others include the squirrels’ favorite—hickories, especially pignut, mockernut, and shagbark—which consists of 10 to 25 % of their diets in a good year and ripen before acorns. But like oaks, as well as the other hard mast producers—American beeches and black walnuts—they are also wind-pollinated.

Hard mast is high in fat, carbohydrates, and protein and is important to at least 180 species of birds and animals in fall and winter, but since it is highly variable in production from year to year, wildlife must depend also on a wide variety of soft mast throughout spring, summer, and fall. These fleshy, perishable fruits high in sugar, vitamins, and carbohydrates include a wide variety of native trees, shrubs, and woody vine species.

Foresters and wildlife biologists, in fact, consider mast to be the woody plant fruits and browse of native trees, shrubs and vines even though the word mast comes from the Old English “maest” which meant the forest tree nuts on the ground that fattened domestic pigs and other animals.

A wide variety of soft mast allows many mammals and birds to survive the lean years of hard mast. Of course, there are always some nuts every year, but ever since the extinction of American chestnut trees which, because they were insect-pollinated and didn’t bloom until summer, reliably produced an excellent crop of nuts, wildlife has had to adjust to a feast or near famine hard mast situation.

Consequently, encouraging biologically diverse meadows and forests, stocked with native trees, shrubs, and woody vine species produces food for wildlife throughout the year. And diverse food leads to diverse wildlife, as we’ve discovered on our property.

Other examples of trees that are insect-pollinated and produce a huge number of seeds every year as well as foliage, twigs and bark are red and striped maples. Striped maple, also called moosewood or goosefoot, has fruit that matures in early fall and is eaten by ruffed grouse, rodents, and songbirds. In addition, it produces browse for deer and bark for rabbits and beaver.

Elk eat the buds, foliate, twigs and bark of red maple, songbirds gorge on the seeds, and squirrels and mice store them for winter.

Basswood is another insect-pollinated tree, producing seeds squirrels and chipmunks consume while deer and rabbits browse its foliage.

The best of the soft mass fruit is that of wild black cherry trees. It fruits abundantly every third or fourth year in August and is pollinated by solitary bees. Seventy bird species feed on the fruit including grouse and wild turkeys. Black bears, raccoons, foxes, rabbits, squirrels, chipmunks and mice relish the dark cherries.

witch-hazel fruit and flowers

Witch-hazel fruit and flowers (Image by Rodger Evans on Flickr, Creative Commons license)

The fruit of sassafras trees, which is high in fat, is eaten by turkeys, bobwhite quail, black bears, pileated woodpeckers and gray catbirds. Rabbits and deer browse its twigs, black bears like its stems and deer its leaves. Despite its popularity, we have many sassafras trees in our forest.

Common witch-hazel, which flowers in late fall, develops woody capsules the following spring and summer. Those capsules contain a pair of shiny, black hard-coated seeds that shoot out in autumn before the next flowering. But squirrels, turkeys, quail, and grouse go after them, especially if the acorn crop fails. Deer browse heavily on witch-hazel, but it persists in growing above the deer line here.

Common spicebush (my personal favorite) produces brilliant spicy red fruits eaten by grouse, pheasants, and quail. It also provides shoots for rabbits and browse for deer, but it too survives and thrives, especially in wet areas along our stream. Our son Dave has planted it as an attractive shrub in our yard and his.

Both red-berried elder, which blooms the same time as the invasive barberry, has red berries available for birds in June or early July, although it only lives on steep slopes here because deer are fond of its browse. Deer also like common elderberry. It blooms in late June or early July and hangs heavy with clusters of dark purple berries favored by birds and humans in late August.

White-throated sparrow with staghorn sumac fruit

White-throated sparrow with staghorn sumac fruit (Kelly Colgan Azar photo on Flickr, Creative Commons license)

Staghorn sumac is making a recovery on our property, living on the sunny edges of meadows and forests. Blooming in late June and early July, its greenish-yellow, fragrant flowers morph into bright red, cone-shaped clusters of fruit that last through the winter, providing food for squirrels, songbirds, grouse, pheasants, turkeys and quail. Deer and rabbits browse on this shrub as well.

Wild berries are a popular summer food. First come the lowbush blueberries as early as mid-June on our powerline right-of-way, followed by the huckleberries. Black bears are particularly fond of them, but so are songbirds, grouse, chipmunks, pheasants, and mice.

Black raspberries ripen in early July and blackberries in early August. Both are incredibly important fruit for songbirds, skunks, opossums, foxes, squirrels, chipmunks, and black bears, while rabbits like their cover and rabbits and deer browse on their stems. Of course, the wildlife must also compete with me, especially in the blackberry patches.

Opossum eating wild grapes

Opossum eating wild grapes (photo by pverdonk on Flickr, Creative Commons license)

Greenbrier of several species has bluish-black berries eaten by songbirds and gamebirds and deer browse them. They browse wild grapevines too, but wild grapes are among the most important and valuable food for wildlife including songbirds, gamebirds, foxes, skunks, raccoons, opossums, squirrels and deer. The vines provide winter shelter for animals and birds too. I remember one winter when the hard mast failed and deer spent the season among the grapevines of the Far Field thicket, yarding up like they do in northern New England.

My list of native trees, shrubs and vines could be greatly expanded. In other parts of Pennsylvania, particularly south of us, still other wildlife food, such as common papaws, are important. But diversity remains the key to providing abundant wildlife food, even in years when hard mast is scarce.