Cool-season Grass Meadows – LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED

January 3, 2024March 30, 2024

Birds of the Sunny Grasslands

With the earth at perihelion (its closest approach to the sun) and with our home star just 27 degrees above the horizon at midday, bright low-angle light offered the perfect opportunity for doing some wildlife photography today. We visited a couple of grasslands managed by the Pennsylvania Game Commission to see what we could find…

Grasslands and Hedgerows — On this State Game Lands parcel, prescribed fire is used to maintain a mix of grasslands and brushy early successional growth. In nearby areas, both controlled fire and mechanical cutting are used to remove invasive species from hedgerows and the understory of woodlots. Fire tolerant native species then have an opportunity to recolonize the forest and improve wildlife habitat. This management method also reduces the fuel load in areas with the potential for uncontrolled wildfires.

The sun-dried fruits of a Common Persimmon tree found growing in a hedgerow. — The sun-dried fruits of a native Common Persimmon tree found growing in a hedgerow.

Savanna-like Grasslands — Just one year ago, mechanical removal of invasive trees and shrubs (including Multiflora Rose) on this State Game Land was followed by a prescribed fire to create this savanna-like grassland.

Hundreds of Song Sparrows were found in the grasses and thickets at both locations.

White-throated Sparrows were also abundant, but prefer the tangles and shrubs of the thickets.

Northern Mockingbirds were vigilantly guarding winter supplies of berries in the woodlots and hedgerows.

In grasses and tangles on wetter ground, about a dozen Swamp Sparrows were discovered.

The adult White-crowned Sparrow is always a welcome find.

Dark-eyed Juncos were encountered only in the vicinity of trees and large shrubs.

Several Savannah Sparrows were observed. Though they’re mostly found in treeless country, this particular one happened to pose atop a clump of shrubs located within, you guessed it, the new savanna-like grasslands.

A tiny bird, even when compared to a sparrow, the Winter Wren often provides the observer with just a brief glimpse before darting away into the cover of a thicket.

Standing Clump of Timber — Within grasslands, scattered stands of live and dead timber can provide valuable habitat for many species of animals.

A "snag" with an excavated nest cavity. — Woodpeckers and other cavity-nesting birds rely upon an abundance of “snags” (standing dead trees) for breeding sites.

This Red-bellied Woodpecker and about a dozen others were found in trees left standing in the project areas.

A Yellow-bellied Sapsucker soaks up some sun.

This very cooperative Pileated Woodpecker seemed to be preoccupied by insect activity on the sun-drenched bark of the trees. This denizen of mature forests will oft times wander into open country where larger lumber is left intact.

Just as things were really getting fun, some late afternoon clouds arrived to dim the already fading daylight. Just then, this Northern Harrier made a couple of low passes in search of mice and voles hidden in the grasses.

August 10, 2023August 14, 2023

Butterflies and More at Boyd Big Tree Preserve Conservation Area

If you’re feeling the need to see summertime butterflies and their numbers just don’t seem to be what they used to be in your garden, then plan an afternoon visit to the Boyd Big Tree Preserve along Fishing Creek Valley Road (PA 443) just east of U.S. 22/322 and the Susquehanna River north of Harrisburg. The Pennsylvania Department of Conservation and Natural Resources manages the park’s 1,025 acres mostly as forested land with more than ten miles of trails. While located predominately on the north slope of Blue Mountain, a portion of the preserve straddles the crest of the ridge to include the upper reaches of the southern exposure.

American Chestnut at Boyd Big Tree Preserve — A grove of American Chestnuts (Castanea dentata) planted at Boyd Big Tree Preserve is part of a propagation program working to restore blight-resistant trees to Pennsylvania and other areas of their former range which included the Appalachians and the upper Ohio River watershed.

Fortunately, one need not take a strenuous hike up Blue Mountain to observe butterflies. Open space along the park’s quarter-mile-long entrance road is maintained as a rolling meadow of wildflowers and cool-season grasses that provide nectar for adult butterflies and host plants for their larvae.

Butterfly Meadow at Boyd Big Tree Preserve — A view looking north at the butterfly meadow and entrance road at Boyd Big Tree Preserve Conservation Area. Second Mountain is in the background.

Walking a Meadow Path — Mowed paths follow the entrance road and a portion of the perimeter of the meadow allowing visitors a chance to wander among the waist-high growth to see butterflies, birds, and blooming plants at close range without trampling the vegetation or risking exposure to ticks.

A Silver-spotted Skipper feeding on nectar from Dogbane (Apocynum cannabinum) flowers. — A Silver-spotted Skipper feeding on nectar from the flowers of Indian Hemp (Apocynum cannabinum). Like the milkweeds, Indian Hemp is a member of the dogbane family (Apocynaceae).

An Eastern Tiger Swallowtail feeding on Common Milkweed.

Great Spangled Fritillary on Common Milkweed. — A Great Spangled Fritillary (Speyeria cybele) on Common Milkweed.

A Black Swallowtail feeding on Common Milkweed nectar. — A Black Swallowtail (Papilio polyxenes) feeding on Common Milkweed nectar.

A Pipevine Swallowtail on Common Milkweed. — A Pipevine Swallowtail (Battus philenor) on Common Milkweed.

A Pipevine Swallowtail on visiting Butterfly Weed. — A Pipevine Swallowtail visiting the brilliant blooms of Butterfly Weed, a favorite of a wide variety of pollinators.

A Black Swallowtail on Butterfly Weed — A Black Swallowtail with damaged wings alights atop a Butterfly Weed flower cluster. Note the pair of parallel rows of red-orange spot on the underside of the hindwing.

A Monarch on Butterfly Weed — A Monarch feeding on nectar from the flowers of Butterfly Weed.

A mating pair of Eastern Tailed Blues. — A mating pair of Eastern Tailed Blues on a Timothy (Phleum pratense) spike.

A female (left) and male Great Spangled Fritillary. — A male Great Spangled Fritillary (right) pursuing a female.

Butterflies aren’t the only colorful insects patrolling the meadows at Boyd Big Tree Preserve. Dragonflies including Common Green Darners are busily pursuing prey, particularly small flying insects like mosquitos, gnats, and flies.

Juvenile Broad-winged Hawk — Dragonflies themselves can become prey and are much sought after by Broad-winged Hawks. This very vocal juvenile gave us several good looks as it ventured from the forest into the skies above the upper meadow during midday. It wasn’t yet a good enough flier to snag a dragonfly, but it will have plenty of opportunities for practice during its upcoming fall migration which, for these Neotropical raptors, will get underway later this month.

Do yourself a favor and take a trip to the Boyd Big Tree Preserve Conservation Area. Who knows? It might actually inspire you to convert that lawn or other mowed space into much-needed butterfly/pollinator habitat.

While you’re out, you can identify your sightings using our photographic guide—Butterflies of the Lower Susquehanna River Watershed—by clicking the “Butterflies” tab at the top this page. And while you’re at it, you can brush up on your hawk identification skills ahead of the upcoming migration by clicking the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab. Therein you’ll find a listing and descriptions of hawk watch locations in and around the lower Susquehanna region. Plan to visit one or more this autumn!

July 30, 2023August 25, 2023

Some Good Reasons to Postpone Mowing Until Mid-August

Here in a series of photographs are just a handful of the reasons why the land stewards at Middle Creek Wildlife Management Area and other properties where conservation and propagation practices are employed delay the mowing of fields composed of cool-season grasses until after August 15 each year.

Eastern Meadowlarks, birds of large pastures, hay lots and other meadows of cool-season grasses, build their nests and raise their young on the ground. In the years since the early twentieth century, loss in the volume of acreage maintained in the lower Susquehanna Valley as grassland habitat types has dramatically reduced the prevalence and abundance of this and other birds with similar nesting requirements. During the most recent fifty years, early and frequent mowing and other practices introduced as part of agriculture’s Green Revolution have all but eliminated ground-nesting grassland species from the region.

Like the meadowlarks, Grasshopper Sparrows (Ammodramus savannarum) nest on the ground in fields of cool-season grasses. Mowing prior to the time the young leave the nest and are able to fly away can obliterate a generation of grassland birds. Because their life span is short, widespread loss of an entire year of reproduction can quickly impact overall populations of native sparrows and other small birds. Delayed mowing can improve numbers of Grasshopper Sparrows as well as Savannah Sparrows, Vesper Sparrows (Pooecetes gramineus), and the very rare Henslow’s Sparrow (Centronyx henslowii).

The Bobolink, like the meadowlark, is a member of the blackbird family (Icteridae). It too requires grasslands free of disturbances like mowing for the duration of the nesting season which, for this particular bird, lasts until mid-August in the lower Susquehanna region. In places lacking their specific habitat requirements, Bobolinks will seldom be detected except as flyovers during migration.

Ring-necked Pheasants were introduced to the lower Susquehanna basin, and their populations were maintained thereafter, by stocking for the purpose of hunting. But throughout the middle twentieth century, there was a substantial population of ring-necks breeding in fields of cool-season grasses in farmlands throughout the region. High-intensity agriculture with frequent mowing eliminated not only nesting habitat in grasslands, but winter cover in areas of early successional growth. Populations of Ring-necked Pheasants, as well as native Northern Bobwhite, crumbled during the late 1970s and early 1980s due to these changes. For these resident birds that don’t migrate or routinely travel great distances to find new places to live and breed, widespread habitat loss can be particularly catastrophic. Not surprisingly, the Northern Bobwhite is no longer found in the Lower Susquehanna River Watershed and has been extirpated from all of Pennsylvania.

At places like Middle Creek Wildlife Management Area where a mix of grasslands, early successional growth, and even some cropland are maintained, the Blue Grosbeak has extended its range well north of the Mason-Dixon and has become a regular nesting species during recent decades. Good habitat management does pay dividends.

Right now is a good time to visit Middle Creek Wildlife Management Area to see the effectiveness a delayed mowing schedule can have when applied to fields of cool-season grasses. If you slowly drive, walk, or bicycle the auto tour route on the north side of the lake, you’ll pass through vast areas maintained as cool-season and warm-season grasses and early successional growth—and you’ll have a chance to see these and other grassland birds raising their young. It’s like a trip back in time to see farmlands they way they were during the middle years of the twentieth century.