Herbicides – LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED

May 22, 2024May 23, 2024

Photo of the Day

Paulownia in Flower — While in flower, this extensive stand of Princess Trees (Paulownia tomentosa) straddling Second Mountain north of Harrisburg might be mistaken for a series of boulder outcrops. Native to eastern Asia, the fast-growing Princess Tree has escaped cultivation to become naturalized in many parts of eastern North America. You’ll currently notice the showy purple blooms on many forested ridges and hilltops throughout the Lower Susquehanna River Watershed. Paulownia tomentosa is also known as the Phoenix Tree, a name derived from its ability, due to its extensive root system, to regenerate following fire. This fast-growing invasive therefore calls for measures in addition to prescribed burns for control within infected forests. Mechanical and/or chemical methods of removal are frequently required.

January 6, 2024January 6, 2024

Birds of Snow-covered Farmland

When the ground becomes snow covered, it’s hard to imagine anything lives in the vast wide-open expanses of cropland found in the Lower Susquehanna River Watershed’s fertile valleys.

Snow-covered Farm Field — A snow-covered field with no standing vegetation. For nearly all wild birds, mammals, and other animals, modern agricultural practices offer no means of sustenance, particularly during the winter months.

Yet, there is one group of birds that can be found scrounging a living from what little exists after a season of high-intensity farming. Meet the Horned Lark.

Horned Larks occur year-round in the lower Susquehanna region. Birds found wintering here are hardy individuals that breed in the arctic tundra, terrain reminiscent of our treeless farmlands. Another population of larks seems to have adapted to no-till farming, nesting with some success in unplowed fields during the early part of the growing season. The impact of herbicide application on survival of these broods could be a topic of research for an energetic student out there…hint, hint.

A Flock of Horned Larks — Nearly invisible on bare ground, Horned Larks are much more conspicuous after a fresh snowfall. For protection from predators, they gather in flocks. During the days of raw manure application, 300 to 500 larks could be found attracted to a freshly spread strip in a snow-covered field. Modern liquid manure, which contains fewer undigested seeds and grains for larks, is not as attractive to these and other birds.

Horned Larks in Snow — During severe storms, we’ve seen Horned Larks remain active throughout the night. We’ve even witnessed them taking shelter by burying themselves in the snow.

Horned Lark in Flight — To find food, Horned Larks are constantly on the move…

Horned Lark — …seeking out bare ground or the seed-bearing tops of plant stems that remain exposed above the snow.

Horned Larks Feeding at Roadside — Following storms, Horned Larks often gather along roadsides where snow removal has revealed “weed” seeds and other tiny morsels that, though they are almost imperceptible to us, are a meal for a Horned Lark.

A Horned Lark munching "weed" seeds. — A Horned Lark munching “weed” seeds.

Horned Larks and Lapland Longsrurs — Flocks of wintering Horned Larks will sometimes contain one or more of the several much less numerous species with a similar proclivity for tundra-like environs during the colder months. We examined this gathering a little bit more closely…

Lapland Longspurs and Horned Larks — …and found these Lapland Longspurs (Calcarius lapponicus). In winter, Lapland Longspurs (the two streaked birds: one to the far left and the other high-stepping the white line) can be hard to discern from the earth tones of farmland habitat. Breeding males, however, are a brilliant white with a chestnut-colored nape and a black bib, mask, and cap. On rare occasions, these males in spectacular alternate plumage can be found in the lower Susquehanna valley prior to their departure to nesting areas near the treeline in northern Canada and Alaska.

A close-up image (through the windshield) of a roadside flock of Horned larks and three Lapland Longspurs (top, far right, and third from bottom).

If you decide to take a little post-storm trip to look for Horned Larks and Lapland Longspurs, be sure to drive carefully. Do your searching on quiet rural roads with minimal traffic. Stop and park only where line-of-sight and other conditions allow it to be done safely. Use your flashers and check your mirrors often. Think before you stop and park—don’t get stuck or make a muddy mess. And most important of all, be aware that you’re on a roadway—get out of the way of traffic.

Flushed from roadside feeding areas by passing automobiles, these Eastern Meadowlarks were previously displaced from their grassland and pasture foraging areas by snow cover.

If you’re not going out to look for larks and longspurs, we do have a favor to ask of you. Please remember to slow down while you’re driving. Not only is this an accident-prone time of year for people in cars and trucks, it’s a dangerous time for birds and other wildlife too. They’re at greatest peril of getting run over while concentrated along roadsides looking for food following snow storms.

The American Pipit is another barren-field specialist that can be found feeding at roadside following snowstorms, particularly when they coincide with the bird’s migration in late fall or early spring. (Vintage 35 mm image)

The Snow Bunting (Plectrophenax nivalis), like the Lapland Longspur, occurs among flocks of Horned Larks in winter. Other barren-ground birds you’ll see feeding along country roads following significant snowfalls include Savannah and Vesper Sparrows.

During mild winters, Killdeer may linger in farmlands where they are more easily heard than seen…until it snows.

September 24, 2023June 19, 2024

Four Common Grasshoppers

Grasshoppers are perhaps best known for the occasions throughout history when an enormous congregation of these insects—a “plague of locusts”—would assemble and rove a region to feed. These swarms, which sometimes covered tens of thousands of square miles or more, often decimated crops, darkened the sky, and, on occasion, resulted in catastrophic famine among human settlements in various parts of the world.

The largest “plague of locusts” in the United States occurred during the mid-1870s in the Great Plains. The Rocky Mountain Locust (Melanoplus spretus), a grasshopper of prairies in the American west, had a range that extended east into New England, possibly settling there on lands cleared for farming. Rocky Mountain Locusts, aside from their native habitat on grasslands, apparently thrived on fields planted with warm-season crops. Like most grasshoppers, they fed and developed most vigorously during periods of dry, hot weather. With plenty of vegetative matter to consume during periods of scorching temperatures, the stage was set for populations of these insects to explode in agricultural areas, then take wing in search of more forage. Plagues struck parts of northern New England as early as the mid-1700s and were numerous in various states in the Great Plains through the middle of the 1800s. The big ones hit between 1873 and 1877 when swarms numbering as many as trillions of grasshoppers did $200 million in crop damage and caused a famine so severe that many farmers abandoned the westward migration. To prevent recurrent outbreaks of locust plagues and famine, experts suggested planting more cool-season grains like winter wheat, a crop which could mature and be harvested before the grasshoppers had a chance to cause any significant damage. In the years that followed, and as prairies gave way to the expansive agricultural lands that presently cover most of the Rocky Mountain Locust’s former range, the grasshopper began to disappear. By the early years of the twentieth century, the species was extinct. No one was quite certain why, and the precise cause is still a topic of debate to this day. Conversion of nearly all of its native habitat to cropland and grazing acreage seems to be the most likely culprit.

The critically endangered Eskimo Curlew (Numenius borealis), a species not photographed since 1962 and not confirmed since 1963, fed on Rocky Mountain Locusts during its spring migration through the Great Plains. Excessive hunting and conversion of grasslands to agriculture are believed responsible for the bird’s demise. (United States Fish and Wildlife Service image by Christina Nelson)

In the Mid-Atlantic States, the mosaic of the landscape—farmland interspersed with a mix of forest and disturbed urban/suburban lots—prevents grasshoppers from reaching the densities from which swarms arise. In the years since the implementation of “Green Revolution” farming practices, numbers of grasshoppers in our region have declined. Systemic insecticides including neonicotinoids keep grasshoppers and other insects from munching on warm-season crops like corn and soybeans. And herbicides including 2,4-D (2,4-Dichlorophenoxyacetic acid) have, in effect, become the equivalent of insecticides, eliminating broadleaf food plants from the pasturelands and hayfields where grasshoppers once fed and reproduced in abundance. As a result, few of the approximately three dozen species of grasshoppers with ranges that include the Lower Susquehanna River Watershed are common here. Those that still thrive are largely adapted to roadsides, waste ground, and small clearings where native and some non-native plants make up their diet.

Here’s a look at four species of grasshoppers you’re likely to find in disturbed habitats throughout our region. Each remains common in relatively pesticide-free spaces with stands of dense grasses and broadleaf plants nearby.

CAROLINA GRASSHOPPER

Dissosteira carolina

Carolina Grasshopper wing — The Carolina Grasshopper is most readily detected and identified when it flies. The colors of the wings resemble those of the Mourning Cloak butterfly.

Great Black Wasp on goldenrod. — Carolina Grasshoppers are among the preferred victims of Great Black Wasps (Sphex pensylvanicus). A female wasp stings the grasshopper to paralyze it, then drags it away to one of numerous cells in an underground burrow where she lays an egg on it. The body of the disabled grasshopper then provides nourishment for the larval wasp.

DIFFERENTIAL GRASSHOPPER

Melanoplus differentialis

An adult female Differential Grasshopper with fully developed wings.

An adult female Differential Grasshopper

TWO-STRIPED GRASSHOPPER

Melanoplus bivittatus

An adult female Two-striped Grasshopper.

RED-LEGGED GRASSHOPPER

Melanoplus femurrubrum

The Red-legged Grasshopper may currently be our most abundant and widespread species.

Protein-rich grasshoppers are an important late-summer, early-fall food source for birds. The absence of these insects has forced many species of breeding birds to abandon farmland or, in some cases, disappear altogether.

Beginning in the early 1930s, the Western Cattle Egret (Bubulcus ibis), a notoriously nomadic species, transited the Atlantic from Africa to colonize the Americas…and they did it without any direct assistance from humans. During the 1970s and early 1980s, a nesting population of Western Cattle Egrets on river islands adjacent to the Susquehanna’s Conejohela Flats off Washington Boro was the largest inland rookery in the northeastern United States. The Lancaster County Bird Club censused the birds each August and found peak numbers in 1981 (7,580). During their years of abundance, V-shaped flocks of cattle egrets from the rookery islands ventured into grazing lands throughout portions of Lancaster, York, Dauphin, and Lebanon Counties to hunt grasshoppers. These daily flights were a familiar summertime sight for nearly two decades. Then, in the early 1980s, reductions in pastureland acreage and plummeting grasshopper numbers quickly took their toll. By 1988, the rookery was abandoned. The cattle egrets had moved on. (Vintage 33 mm image)

During the summer and early fall, juvenile and adult Ring-necked Pheasants feed heavily on grasshoppers. Earlier and more frequent mowing along with declining numbers of grasshoppers on farmlands due to an increase in pesticide use were factors contributing to the crash of the pheasant population in the early 1980s.

To the delight of Wild Turkeys, each of the four species of grasshoppers shown above frequents clearings and roadsides adjacent to forest areas. While changes in grasshopper distribution have been detrimental to populations of birds like pheasants, they’ve created a feeding bonanza for turkeys.

Wild Turkeys feeding on grasshoppers along a forest road. — Wild Turkeys feeding on an abundance of grasshoppers along a forest road.

American Kestrel Feeding on Grasshopper — An American Kestrel feeds on a grasshopper while ignoring the abundance of Spotted Lanternflies swarming the adjacent utility pole. In Susquehanna valley farmlands, grasshopper and kestrel numbers are down. Lanternflies, on the other hand, have got it made.

Early Successional Growth — Maintaining areas bordering roads, forests, wetlands, farmlands, and human development in a state of early succession can provide and ideal mix of mature grasses and broadleaf plants for grasshoppers, pollinators, birds, and other wildlife.

September 8, 2023September 8, 2023

Photo of the Day

The Broad-necked Root Borer (Prionus laticollis) is one of the Lower Susquehanna River Watershed’s largest insects. Its larvae feed on woody roots for more than two years before pupating and thereafter emerging as adult beetles. The distribution of root borers is not totally random. They are often attracted to distressed trees and shrubs. This particular specimen was found along a forest road where herbicide application, soil dehydration, and a recent wildfire has weakened and killed numerous oaks, poplars, and maples. As they feed, root borer larvae will help begin the process of reducing the remains of these trees into soil nutrients that will benefit regeneration of forest plants at this site.

March 30, 2023April 11, 2023

Purple Haze Across the Fields

Have you noticed a purple haze across the fields right now? If so, you may have wondered, “What kind of flowers are they?”

A purple haze of color stretches across fields not already green with cold-season crops like winter wheat.

Say hello to Purple Dead Nettle (Lamium purpureum), a non-native invasive species that has increased its prevalence in recent years by finding an improved niche in no-till cropland. Purple Dead Nettle, also known as Red Dead Nettle, is native to Asia and Europe. It has been a familiar early spring “weed” in gardens, along roadsides, and in other disturbed ground for decades.

Purple Dead Nettle owes its new-found success to the timing of its compressed growing season. Its tiny seeds germinate during the fall and winter, after crops have been harvested and herbicide application has ended for the season. The plants flower early in the spring and are thus particularly attractive to Honey Bees and other pollinators looking for a source of energy-rich nectar as they ramp up activity after winter lock down. In many cases, Purple Dead Nettle has already completed its flowering cycle and produced seeds before there is any activity in the field to prepare for planting the summer crop. The seeds spend the warmer months in dormancy, avoiding the hazards of modern cultivation that expel most other species of native and non-native plants from the agricultural landscape.

Purple Dead Nettle in Bloom — Flowering Purple Dead Nettle as a volunteer cover crop among last year’s corn stubble in a no-till field.

Purple Dead Nettle, Common Dandelion, and Shepherd's Purse — We call them “weeds”, but what do we know? Purple Dead Nettle, Common Dandelion, and Shepherd’s Purse (Capsella bursa-pastoris), three edible non-native invasive species with similar life cycles seen here flowering along a rural road among fields where intensive farming is practiced. Shepard’s Purse, like many members of the mustard family, is already producing seeds at the bottom of the flower cluster by the time the uppermost buds open for business.

Spraying Herbicide — In preparation for seeding of a warm-season crop, herbicide is applied on a no-till field to kill Shepherd’s Purse and other cool-season plants. To help prevent sediment and nutrient discharge from lands where high-intensity agriculture is practiced, no-till methods are used to reduce runoff from the areas of bare soil that would otherwise be created by traditional plowing.

While modern farming has eliminated a majority of native plant and animal species from agricultural lands of the lower Susquehanna valley, its crop management practices have simultaneously invited vigorous invasion by a select few non-native species. High-intensity farming devotes its acreage to providing food for a growing population of people—not to providing wildlife habitat. That’s why it’s so important to minimize our impact on non-farm lands throughout the remainder of the watershed. If we continue subdividing, paving, and mowing more and more space, we’ll eventually be living in a polluted semi-arid landscape populated by little else but non-native invasive plants and animals. We can certainly do better than that.

July 29, 2022May 20, 2024

Monarch an Endangered Species: What You Can Do Right Now

This month, the International Union for Conservation of Nature (I.U.C.N.) added the Migratory Monarch Butterfly (Danaus plexippus plexippus) to its “Red List of Threatened Species”, classifying it as endangered. Perhaps there is no better time than the present to have a look at the virtues of replacing areas of mowed and manicured grass with a wildflower garden or meadow that provides essential breeding and feeding habitat for Monarchs and hundreds of other species of animals.

Monarch on Common Milkweed Flower Cluster — A recently arrived Monarch visits a cluster of fragrant Common Milkweed flowers in the garden at the susquehannawildlife.net headquarters. Milkweeds included among a wide variety of plants in a garden or meadow habitat can help local populations of Monarchs increase their numbers before the autumn flights to wintering grounds commence in the fall. Female Monarchs lay their eggs on milkweed leaves, then, after hatching, the larvae (caterpillars) feed on them before pupating.

If you’re not quite sure about finally breaking the ties that bind you to the cult of lawn manicuring, then compare the attributes of a parcel maintained as mowed grass with those of a space planted as a wildflower garden or meadow. In our example we’ve mixed native warm season grasses with the wildflowers and thrown in a couple of Eastern Red Cedars to create a more authentic early successional habitat.

Comparison of Mowed Grass to Wildflower Meadow — * Particularly when native warm-season grasses are included (root depth 6′-8′)

Still not ready to take the leap. Think about this: once established, the wildflower planting can be maintained without the use of herbicides or insecticides. There’ll be no pesticide residues leaching into the soil or running off during downpours. Yes friends, it doesn’t matter whether you’re using a private well or a community system, a wildflower meadow is an asset to your water supply. Not only is it free of man-made chemicals, but it also provides stormwater retention to recharge the aquifer by holding precipitation on site and guiding it into the ground. Mowed grass on the other hand, particularly when situated on steep slopes or when the ground is frozen or dry, does little to stop or slow the sheet runoff that floods and pollutes streams during heavy rains.

What if I told you that for less than fifty bucks, you could start a wildflower garden covering 1,000 square feet of space? That’s a nice plot 25′ x 40′ or a strip 10′ wide and 100′ long along a driveway, field margin, roadside, property line, swale, or stream. All you need to do is cast seed evenly across bare soil in a sunny location and you’ll soon have a spectacular wildflower garden. Here at the susquehannawildllife.net headquarters we don’t have that much space, so we just cast the seed along the margins of the driveway and around established trees and shrubs. Look what we get for pennies a plant…

Here’s a closer look…

Lance-leaved Coreopsis (Coreopsis lanceolata), a perennial.

Black-eyed Susan, a biennial or short-lived perennial.

Black-eyed Susan "Gloriosa Daisy" — “Gloriosa Daisy”, a variety of Black-eyed Susan, a biennial or short-lived perennial.

Purple Coneflower, an excellent perennial for pollinators. The ripe seeds provide food for American Goldfinches.

A short variety of Common Sunflower, an annual and a source of free bird seed.

All this and best of all, we never need to mow.

Around the garden, we’ve used a northeast wildflower mix from American Meadows. It’s a blend of annuals and perennials that’s easy to grow. On their website, you’ll find seeds for individual species as well as mixes and instructions for planting and maintaining your wildflower garden. They even have a mix specifically formulated for hummingbirds and butterflies.

Annuals in bloom — When planted in spring and early summer, annuals included in a wildflower mix will provide vibrant color during the first year. Many varieties will self-seed to supplement the display provided by biennials and perennials in subsequent years.

Wildflower Seed Mix — A northeast wildflower mix from American Meadows. There are no fillers. One pound of pure live seed easily plants 1,000 square feet.

Nothing does more to promote the spread and abundance of non-native plants, including invasive species, than repetitive mowing. One of the big advantages of planting a wildflower garden or meadow is the opportunity to promote the growth of a community of diverse native plants on your property. A single mowing is done only during the dormant season to reseed annuals and to maintain the meadow in an early successional stage—preventing reversion to forest.

For wildflower mixes containing native species, including ecotypes from locations in and near the Lower Susquehanna River Watershed, nobody beats Ernst Conservation Seeds of Meadville, Pennsylvania. Their selection of grass and wildflower seed mixes could keep you planting new projects for a lifetime. They craft blends for specific regions, states, physiographic provinces, habitats, soils, and uses. Check out these examples of some of the scores of mixes offered at Ernst Conservation Seeds…

- - Pipeline Mixes
  - Pasture, Grazing, and Hay Mixes
  - Cover Crops
  - Pondside Mixes
  - Warm-season Grass Mixes
  - Retention Basin Mixes
  - Wildlife Mixes
  - Pollinator Mixes
  - Wetland Mixes
  - Floodplain and Riparian Buffer Mixes
  - Rain Garden Mixes
  - Steep Slope Mixes
  - Solar Farm Mixes
  - Strip Mine Reclamation Mixes

We’ve used their “Showy Northeast Native Wildflower and Grass Mix” on streambank renewal projects with great success. For Monarchs, we really recommend the “Butterfly and Hummingbird Garden Mix”. It includes many of the species pictured above plus “Fort Indiantown Gap” Little Bluestem, a warm-season grass native to Lebanon County, Pennsylvania, and milkweeds (Asclepias), which are not included in their northeast native wildflower blends. More than a dozen of the flowers and grasses currently included in this mix are derived from Pennsylvania ecotypes, so you can expect them to thrive in the Lower Susquehanna River Watershed.

Swamp Milkweed, a perennial species, is included in the Ernst Seed “Butterfly and Hummingbird Garden Mix”. It is a favorite of female Monarchs seeking a location to deposit eggs.

Monarch Caterpillar feeding on Swamp Milkweed — A Monarch larva (caterpillar) feeding on Swamp Milkweed.

Butterfly Weed (Asclepias tuberosa) is included in the Ernst Seed “Butterfly and Hummingbird Garden Mix”. This perennial is also known as Butterfly Milkweed.

Tiger Swallowtails visiting Butterfly Weed — Eastern Tiger Swallowtails are among the dozens of species of pollinators that will visit Butterfly Weed.

In addition to the milkweeds, you’ll find these attractive plants included in Ernst Conservation Seed’s “Butterfly and Hummingbird Garden Mix”, as well as in some of their other blends.

The perennial Wild Bergamot, also known as Bee Balm, is an excellent pollinator plant, and the tubular flowers are a favorite of hummingbirds.

Oxeye is adorned with showy clusters of sunflower-like blooms in mid-summer. It is a perennial plant.

Plains Coreopsis (Coreopsis tinctoria), also known as Plains Tickseed, is a versatile annual that can survive occasional flooding as well as drought.

Gray-headed Coneflower (Ratibida pinnata), a tall perennial, is spectacular during its long flowering season.

Monarch on goldenrod. — Goldenrods are a favorite nectar plant for migrating Monarchs in autumn. They seldom need to be sown into a wildflower garden; the seeds of local species usually arrive on the wind. They are included in the “Butterfly and Hummingbird Garden Mix” from Ernst Conservation Seeds in low dose, just in case the wind doesn’t bring anything your way.

Is something missing from your seed mix? You can purchase individual species from the selections available at American Meadows and Ernst Conservation Seeds. Partridge Pea is a good native annual to add. It is a host plant for the Cloudless Sulphur butterfly and hummingbirds will often visit the flowers. It does really well in sandy soils.

Indiangrass in flower. — Indiangrass is a warm-season species that makes a great addition to any wildflower meadow mix. Its deep roots make it resistant to drought and ideal for preventing erosion.

Why not give the Monarchs and other wildlife living around you a little help? Plant a wildflower garden or meadow. It’s so easy, a child can do it.

Planting a riparian buffer with wildflowers and warm-season grasses — Volunteers sow a riparian buffer on a recontoured stream bank using wildflower and warm-season grass seed blended uniformly with sand. By casting the sand/seed mixture evenly over the planting site, participants can visually assure that seed has been distributed according to the space calculations.

Riparian Buffer of wildflowers — The same seeded site less than four months later.

Monarch Pupa — A Monarch pupa from which the adult butterfly will emerge.

July 25, 2022August 15, 2022

If I Had a Pool, Here’s What I Would Do

On these hot and steamy days of summer, I get to thinking about how great it would be to have a swimming pool. Maybe I would take a little dip, you know, just to cool down. But when I really get to thinking about it, I just might do what the professor has done with his pool.

Or maybe I would do what this lady did with her pool.

Or what this lady did.

Yep, I’d do this.

This is what I’d do.

Wouldn’t you?

April 22, 2022May 13, 2022

Times Are Tough

Rising prices, an exhausted workforce, political polarization, and pandemic fatigue—times are tough. Product shortages have the consumer culture in a near panic. Some say the future just isn’t what it used to be.

Well, Uncle Tyler Dyer reminds us that things could be worse. He shares with us this observation, “Man, as long as people are spending money poisoning the weeds on their lawns instead of eating them, things aren’t that bad.”

Uncle Ty is particularly fond of the Common Dandelion (Taraxacum officinale), “Check it out. Roasted dandelion roots can make a coffee substitute, the blossoms a wine, and the leaves used to create my favorites, nutrient-dense salads or green vegetable dishes.”

Dandelion Salad — Uncle Ty Dyer’s lunch, fresh dandelion greens and hot bacon dressing.

So have a homegrown salad and remember, maybe things aren’t that bad after all.

May 15, 2020August 14, 2023

The Layover

After nearly a full week of record-breaking cold, including two nights with a widespread freeze, warm weather has returned. Today, for the first time this year, the temperature was above eighty degrees Fahrenheit throughout the lower Susquehanna region. Not only can the growing season now resume, but the northward movement of Neotropical birds can again take flight—much to our delight.

A rainy day on Friday, May 8, preceded the arrival of a cold arctic air mass in the eastern United States. It initiated a sustained layover for many migrating birds.

Bobolinks (Dolichonyx oryzivorus) in flocks of as many as fifty birds gathered in weedy meadows and alfalfa fields for the week.

A Bobolink sheltering in a field of Sweet Vernal Grass (Anthoxanthum odoratum) during the rain on Friday, May 8th.

Two of seven Solitary Sandpipers (Tringa solitaria) in a wet field on Friday, May 8. Not-so-solitary after all.

Grounded by inclement weather, Rose-breasted Grosbeaks (Pheucticus ludovicianus) made visits to suburban bird feeders in the lower Susquehanna valley. (Charles A. Fox image)

Freeze warnings were issued for five of the next six mornings. The nocturnal flights of migrating birds, most of them consisting of Neotropical species by now, appeared to be impacted. Even on clear moonlit nights, these birds wisely remained grounded. Unlike the more hardy species that moved north during the preceding weeks, Neotropical birds rely heavily on insects as a food source. For them, burning excessive energy by flying through cold air into areas that may be void of food upon arrival could be a death sentence. So they wait.

A freeze warning was issued for Saturday morning, May 9, in the counties colored dark blue on the map. (NOAA/National Weather Service image)

This radar image from 3:28 A.M. Saturday morning, May 9, indicates a minor movement of birds in the Great Plains, but there are no notable returns shown around weather radar sites in the freeze area, including the lower Susquehanna valley. (NOAA/National Weather Service image)

To avoid the cold wind on Saturday, May 9, this Veery was staying low to the ground within a thicket of shrubs in the forest.

This Black-throated Blue Warbler avoided the treetops and spent time in the woodland understory. He sang not a note. With birds conserving energy for the cold night(s) ahead, it was uncharacteristically quiet for the second Saturday in May.

A secretive Northern Waterthrush (Parkesia noveboracensis) remained in a wetland thicket.

A Scarlet Tanager (Piranga olivacea) tucks his bill beneath a wing and fluffs-up to fight off the cold during a brief May 9th snow flurry.

In open country, gusty winds kept Eastern Kingbirds, a species of flycatcher, near the ground in search of the insects they need to sustain them.

Horned Larks are one of the few birds that attempt to scratch out an existence in cultivated fields. The application of herbicides and the use of systemic insecticides (including neonicotinoids) eliminates nearly all weed seeds and insects in land subjected to high-intensity farming. For most birds, including Neotropical migrants, cropland in the lower Susquehanna valley has become a dead zone. Birds and other animals might visit, but they really don’t “live” there anymore.

Unable to find flying insects over upland fields during the cold snap, swallows concentrated over bodies of water to feed. Some Tree Swallows may have abandoned their nests to survive this week’s cold. Fragmentation of habitats in the lower Susquehanna valley reduces the abundance and diversity of natural food sources for wildlife. For birds like swallows, events like late-season freezes, heat waves, or droughts can easily disrupt their limited food supply and cause brood failure.

For this Barn Swallow, attempting to hunt insects above the warm pavement of a roadway had fatal consequences.

Another freeze warning was issued for Sunday morning, May 10, in the counties colored dark blue on this map. (NOAA/National Weather Service image)

This radar image from 4:58 A.M. Sunday morning, May 10, again indicates the absence of a flight of migrating birds in the area subjected to freezing temperatures. Unlike migrants earlier in the season, the Neotropical species that move north during the May exodus appear unwilling to resume their trek during freezing weather. (NOAA/National Weather Service image)

On Sunday evening, May 10, a liftoff of nocturnal migrants is indicated around radar sites along the Atlantic Coastal Plain and, to a lesser degree, in central Pennsylvania. The approaching rain and yet another cold front quickly grounded this flight.

After a one day respite, yet another freeze warning was issued for Tuesday morning, May 12. (NOAA/National Weather Service image)

And again, no flight in the freeze area. (NOAA/National Weather Service image)

The freeze warning for Wednesday morning, May 13. (NOAA/National Weather Service image)

And the nocturnal flight: heavy in the Mississippi valley and minimal in the freeze area. (NOAA/National Weather Service image)

The freeze on Thursday morning, May 14. (NOAA/National Weather Service image)

At 3:08 A.M. on May 14th, a flight is indicated streaming north through central Texas and dispersing into the eastern half of the United States, but not progressing into New England. (NOAA/National Weather Service image)

The flight at eight minutes after midnight this morning. Note the stormy cold front diving southeast across the upper Mississippi valley. As is often the case, the concentration of migrating birds is densest in the warm air ahead of the front. (NOAA/National Weather Service image)

Today throughout the lower Susquehanna region, bird songs again fill the air and it seems to be mid-May as we remember it. The flights have resumed.

Indigo Bunting numbers are increasing as breeding populations arrive and migrants continue through. Look for them in thickets along utility and railroad right-of-ways.

Common Yellowthroats and other colorful warblers are among the May migrants currently resuming their northward flights.

The echoes of the songs of tropical birds are beginning to fill the forests of the lower Susquehanna watershed. The flute-like harmonies of the Wood Thrush are among the most impressive.

Ovenbirds are ground-nesting warblers with a surprisingly explosive song for their size. Many arrived within the last two days to stake out a territory for breeding. Listen for “teacher-teacher-teacher” emanating from a woodland near you.

August 31, 2018March 30, 2024

Noxious Benefactor

It’s sprayed with herbicides. It’s mowed and mangled. It’s ground to shreds with noisy weed-trimmers. It’s scorned and maligned. It’s been targeted for elimination by some governments because it’s undesirable and “noxious”. And it has that four letter word in its name which dooms the fate of any plant that possesses it. It’s the Common Milkweed, and it’s the center of activity in our garden at this time of year. Yep, we said milk-WEED.

Now, you need to understand that our garden is small—less than 2,500 square feet. There is no lawn, and there will be no lawn. We’ll have nothing to do with the lawn nonsense. Those of you who know us, know that the lawn, or anything that looks like lawn, are through.

Anyway, most of the plants in the garden are native species. There are trees, numerous shrubs, some water features with aquatic plants, and filling the sunny margins is a mix of native grassland plants including Common Milkweed. The unusually wet growing season in 2018 has been very kind to these plants. They are still very green and lush. And the animals that rely on them are having a banner year. Have a look…

The flowers of the Common Milkweed were exceptionally fragrant this year. At their peak in early June, their hyacinth-or lilac-like aroma was so prevalent, it drifted into our building and overwhelmed the stink of the neighbor’s filthy dumpster that he had placed 12 feet away from our walls (100 feet from his).

Common Milkweed attracts a pollinating Greenbottle Fly (Lucilia species). The dumpster attracts the invasive House Fly (Musca domestica), carrier of dysentery, typhoid, and other wonderful diseases. Are you following this? Remember as we proceed, milkweed is “noxious”.

Busy Eastern Carpenter Bees (Xylocopa virginica) load up with pollen from the flowers of the Common Milkweed.

A Red Milkweed Beetle (Tetraopes tetrophthalmus) munches on a tender fresh Common Milkweed leaf in mid-June.

Following the pollination of the flowers, seed pods will begin to grow. We trim these off the plants. The removal of the extra weight allows most of the stems to remain erect through stormy weather. You’ll still get new plants from underground runners. As you may have guessed, we’re trying to keep these plants upright and strong to host Monarch butterfly larvae.

We’ve planted a variety of native grassland species to help support the milkweed structurally and to provide a more complete habitat for Monarch butterflies and other native insects. This year, these plants are exceptionally colorful for late-August due to the abundance of rain. The warm season grasses shown below are the four primary species found in the American tall-grass prairies and elsewhere.

Big Bluestem, a native warm-season grass in flower.

Little Bluestem (Schizachyrium scoparium “Fort Indiantown Gap”) in flower. This variety grows on the tank range at the military base where the armored vehicles and prescribed burns substitute for the herd animals and fires of the prairie to prevent succession and allow it to thrive.

Partridge Pea can tolerate sandy soil and is a host plant for vagrant Cloudless Sulphur butterflies.

Black-eyed Susan (Rudbeckia hirta) is a popular native grassland wildflower.

Indiangrass (Sorghastrum nutans) in flower. This and the other native plants shown here are available as seed from Ernst Seed Company in Meadville (PA). They have an unbelievably large selection of indigenous species. You can plant a small plot or acres and acres using really good mixes blended for purposes ranging from reclaiming pipeline right-of-ways and strip mines to naturalizing backyard gardens.

A Red Admiral (Vanessa atalanta) butterfly, a migratory species like the Monarch, on Purple Coneflower (Echinacea purpurea). Yes, it is that Echinacea, the same one used as a supplement and home remedy.

There was Monarch activity in the garden today like we’ve never seen before—and it revolved around milkweed and the companion plants.

A female Monarch laying eggs on a Common Milkweed leaf.

A third instar Monarch caterpillar with Oleander Aphids (Aphis nerii) on a Common Milkweed leaf. Both of these insect species absorb toxins from the milkweed which makes them distasteful to predators.

Fifth instar (left and center) and fourth instar (right) monarch caterpillars devour a Common Milkweed leaf. There were over thirty of these caterpillars in just a ten by ten feet area this morning. We hope that if you’re keeping a habitat for Monarchs, you’re enjoying the same fortune right now!

A slow-moving Monarch stopped for a break after making the circuit to deposit eggs on milkweed throughout the garden.

Third instar (top), fourth instar (right), and fifth instar (left) Monarch caterpillars quickly consume the leaf of a Common Milkweed plant. Caterpillars emerging from eggs deposited today may not have sufficient late-season food to complete the larval segment of their life cycle. Need more milkweed!

After benefiting from the nourishment of the Common Milkweed plant, a fifth instar Monarch caterpillar begins pupation on Big Bluestem grass.

Two hours later, the chrysalis is complete.

Another chrysalis, this one on flowering Switchgrass just two feet away from the previous one. An adult Monarch will emerge from this pupa to become part of what we hope will be the most populated southbound exodus for the species in over five years.

There it is, soon ready to fly away. And all courtesy of the noxious milkweed.

A chrysalis can often be found on man-made objects too. This one is on the rim of a flower pot.

Ornamental flowers can attract adult Monarch butterflies seeking nectar. We’re now more careful to select seeds and plants that have not been treated with neonicotinoid insecticides. There’s growing concern over the impact these compounds may be having on pollinating species of animals. Oh…and we don’t mow, whack, cut, mutilate, or spray herbicides on our milkweed, but you probably figured that out already.

SOURCES

Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York.

April 3, 2018August 15, 2022

Winter Won’t Let Go…the Birds Don’t Care

It seems as though the birds have grown impatient for typical spring weather to arrive. The increase in hours of daylight has signaled them that breeding time is here. No further delays can be entertained. They’ve got a schedule to keep.

Thursday, March 29: Winds began blowing from the southwest, breaking a cold spell which had persisted since last week’s snowfall. Birds were on the move ahead of an approaching rainy cold front.

Friday, March 30: Temperatures reached 60 degrees at last. Birds were again moving north through the day, despite rain showers and a change in wind direction—from the northwest and cooler following the passage of the front in the late morning.

Flocks of Double-crested Cormorants followed the Susquehanna River north in numerous V-shaped flocks during the recent several days.

There were Turkey Vultures by the hundreds on the way north.

Saturday, March 31: It was cooler, but birds were still on the wing headed north.

At sunrise, a migrating Northern Flicker stopped by at a suet feeder to refuel.

Osprey pairs have arrived at nest sites on the lower Susquehanna.

Sunday, April 1: The morning was pleasant, but conditions became cooler and breezy in the afternoon. Migratory and resident birds began feeding ahead of another storm.

A distant flock of fast-flying Bonaparte’s Gulls *(Chroicocephalus philadelphia)* moves expeditiously up the Susquehanna at Conewago Falls as winds begin to pick up during the late morning. Are they hurrying to get north of the path of the forthcoming weather system?

A Mourning Dove *(Zenaida macroura)* feeds in anticipation of a snowy night ahead.

A male Downy Woodpecker devours a late-afternoon meal.

This Tufted Titmouse *(Baeolophus bicolor)*, a cavity-nesting species, is distracted by a potential new home.

Dark-eyed Juncos winter in the lower Susquehanna valley. During the month of April, they will begin departing for their breeding grounds, some nesting in the mountains just to our north.

A male American Goldfinch is progressing through molt into a showy breeding (alternate) plumage.

A male House Finch takes a break from its melodious song to feed before the arrival of our next spring snow. His mate is already incubating eggs in a nest not far away.

Northern Cardinals *(Cardinalis cardinalis)* feed through the late afternoon, often as the last birds out-and-about before darkness. This male remains close to his mate as she forages beneath nearby shrubs.

Monday, April 2: Snow fell again, overnight and through the morning—a couple of inches. Most of the snow had melted away by late afternoon.

Horned Larks are plentiful in large open bare-soil (tilled) farmlands in winter, particularly near fresh manure. Their sandy-tan coloration hides them well, and they are seldom noticed unless spotted at roadside following snow storms. Horned Larks are migratory ground-nesting birds found in many sparsely vegetated habitats including tundra, parched fields and prairies, beaches, and even airports. There is a breeding population in the lower Susquehanna valley which may be increasingly attracted to favorable nesting habitat created in some no-till fields, possibly using a window of opportunity between the demise of cold-season cover crops and the ascendency of the warm-season crops to complete a brood cycle. Comparing the site selection and success rates of nesting Horned Larks under various crop management methods, including reactions to herbicide use, could be an enlightening study project for inquisitive minds. (Hint-Hint)

The dainty Chipping Sparrow has arrived. This species commonly nests in small trees, often in suburban gardens.

August 7, 2017August 27, 2023

Fussy Eaters

She ate only toaster pastries…that’s it…nothing else. Every now and then, on special occasions, when a big dinner was served, she’d have a small helping of mashed potatoes, no gravy, just plain, thank you. She received all her nutrition from several meals a week of macaroni and cheese assembled from processed ingredients found in a cardboard box. It contains eight essential vitamins and minerals, don’t you know? You remember her, don’t you?

Adult female butterflies must lay their eggs where the hatched larvae will promptly find the precise food needed to fuel their growth. These caterpillars are fussy eaters, with some able to feed upon only one particular species or genus of plant to grow through the five stages, the instars, of larval life. The energy for their fifth molt into a pupa, known as a chrysalis, and metamorphosis into an adult butterfly requires mass consumption of the required plant matter. Their life cycle causes most butterflies to be very habitat specific. These splendid insects may visit the urban or suburban garden as adults to feed on nectar plants, however, successful reproduction relies upon environs which include suitable, thriving, pesticide-free host plants for the caterpillars. Their survival depends upon more than the vegetation surrounding the typical lawn will provide.

The Monarch (Danaus plexippus), a butterfly familiar in North America for its conspicuous autumn migrations to forests in Mexico, uses the milkweeds (Asclepias) almost exclusively as a host plant. Here at Conewago Falls, wetlands with Swamp Milkweed (Asclepias incarnata) and unsprayed clearings with Common Milkweed (A. syriaca) are essential to the successful reproduction of the species. Human disturbance, including liberal use of herbicides, and invasive plant species can diminish the biomass of the Monarch’s favored nourishment, thus reducing significantly the abundance of the migratory late-season generation.

Monarch caterpillar after a fourth molt. The fifth instar feeding on Swamp Milkweed.

A fifth molt begets the Monarch pupa, the chrysalis, from which the showy adult butterfly will emerge.

Adult Monarch feeding on Goldenrod *(Solidago)* nectar.

Butterflies are good indicators of the ecological health of a given environment. A diversity of butterfly species in a given area requires a wide array of mostly indigenous plants to provide food for reproduction. Let’s have a look at some of the species seen around Conewago Falls this week…