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.
You need to get outside and go for a walk. You’ll be sorry if you don’t. It’s prime time to see wildlife in all its glory. The songs and colors of spring are upon us!
Flooding that resulted from mid-week rains is subsiding. The muddy torrents of Conewago Falls are seen here racing by the powerhouse at the York Haven Dam.Receding waters will soon leave the parking area at Falmouth and other access points along the river high and dry.Migrating Yellow-rumped Warblers are currently very common in the riparian woodlands near Conewago Falls. They and all the Neotropical warblers, thrushes, vireos, flycatchers are moving through the Susquehanna watershed right now.A Baltimore Oriole feeds in a riverside maple tree.Ruby-crowned Kinglets are migrating through the Susquehanna valley. These tiny birds may be encountered among the foliage of trees and shrubs as they feed upon insects .Gray Catbirds are arriving. Many will stay to nest in shrubby thickets and in suburban gardens.American Robins and other birds take advantage of rising flood waters to feed upon earthworms and other invertebrates that are forced to the soil’s surface along the inundated river shoreline.Spotted Sandpipers are a familiar sight as they feed along water’s edge.The Yellow Warbler (Setophaga petechia) is a Neotropical migrant that nests locally in wet shrubby thickets. Let your streamside vegetation grow and in a few years you just might have these “wild canaries” singing their chorus of “sweet-sweet-sweet-I’m-so-sweet” on your property.
If you’re not up to a walk and you just want to go for a slow drive, why not take a trip to Middle Creek Wildlife Management Area and visit the managed grasslands on the north side of the refuge. To those of us over fifty, it’s a reminder of how Susquehanna valley farmlands were before the advent of high-intensity agriculture. Take a look at the birds found there right now.
Red-winged Blackbirds commonly nest in cattail marshes, but are very fond of untreated hayfields, lightly-grazed pastures, and fallow ground too. These habitats are becoming increasingly rare in the lower Susquehanna region. Farmers have little choice, they either engage in intensive agriculture or go broke.Nest boxes are provided for Tree Swallows at the refuge.Numbers of American Kestrels have tumbled with the loss of grassy agricultural habitats that provide large insects and small rodents for them to feed upon.White-crowned Sparrows (Zonotrichia leucophrys) are a migrant and winter resident species that favors small clumps of shrubby cover in pastures and fallow land.When was the last time you saw an Eastern Meadowlark (Sturnella magna) singing “spring-of-the-year” in a pasture near your home?And yes, the grasslands at Middle Creek do support nesting Ring-necked Pheasants (Phasianus colcichus). If you stop for a while and listen, you’ll hear the calls of “kowk-kuk” and a whir of wings. Go check it out.
And remember, if you happen to own land and aren’t growing crops on it, put it to good use. Mow less, live more. Mow less, more lives.
