Common Cattail – LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED

May 22, 2025May 24, 2025

Five Flowering Plants for Cleaner Water

Currently in the Lower Susquehanna River Watershed, you can find these five species of herbaceous plants in full bloom. As they grow, they and others like them help to purify waters within their respective ecosystems by taking up nutrients—namely, the nitrogen and phosphorus that can lead to detrimental algal blooms and eutrophication in ponds, lakes, streams, and rivers.

(United States Geological Survey image by Virginia-West Virginia Science Center)

The Marsh Blue Violet (Viola cucullata) is most frequently found growing in the wet soils of forest bottomlands, usually where springs first break the earth’s surface and begin slowly trickling away to form a small brook or join an existing stream. The blooms are recognized by their darker purple centers and their long stems.

The seldom-noticed flowers of the Soft Rush (Juncus effusus), also known as the Common Rush, emerge from the sides of its quill-like stems. This wetland species is found in damp soils, sometimes in standing water, and grows in stiff, erect clumps that persist through winter. When found in pastures, Soft Rush is seldom of interest to cattle or other livestock. It therefore doesn’t lure these animals into muddy, puddle-prone areas. When subjected to heavy grazing in dry weather and flooding during wet spells, these puddle sites may host nearly pure stands of Soft Rush, the only plant able to thrive there. When it comes to nutrient uptake in these soggy sections of the meadow, the soft Rush is the lone ranger. Soft Rush seeds are available from Ernst Conservation Seeds in Meadville, PA, and are included in many of their mixes formulated for stormwater management basins and other wet soil applications.

Larger Blue Flag (Iris versicolor) is a plant of wetlands and shorelines. It can be grown as an emergent in ponds and lakes where it will help to absorb nutrients from both the water and the underlying substrate.

The Yellow Iris (Iris pseudacorus), also known as the Water Flag, is native to Eurasia and Africa. Seen here growing as an emergent among native Common Cattails (a superb water purifier), the Yellow Iris can easily escape cultivation and become invasive. The showy flowers and water-cleansing benefits of this plant make it attractive for use in the garden or farm pond, but considerations must be made for its aggressive growth and proclivity to escape to neighboring habitats. If you’re purchasing irises for transplanting, you’re probably better off sticking with the native Larger Blue Flag; it is far less vigorous and you’ll be able to grow other aquatic species along with it.

In large ponds, lakes, and low-gradient streams, one of the best aquatic plants for sequestering nutrients and clarifying water is Spatterdock, also known as Cow-lily or Yellow Pond Lily. Spatterdock does best as an emergent in shallow water along the shoreline. It grows well in full sunshine and makes excellent habitat for wildlife. Depending on the nutrient load from fish, waterfowl, decaying vegetation, and other sources, plant cover may need to be as high as 30% or more of the surface area to keep algae from overtaking a lake or large pond. Spatterdock can often be used to help fulfill these needs while still offering open water beneath the leaves and between the stems for fish, amphibians, reptiles, and macroinvertebrates to thrive.

May 13, 2025May 13, 2025

Nest Builders at Work

For many animals, an adequate shelter is paramount for their successful reproduction. Here’s a sample of some of the lower Susquehanna valley’s nest builders in action…

Pileated Woodpecker Excavating Nest — Many of our year-round resident bird species get a head start on the breeding season as cavity nesters. Some of these mated pairs use naturally occurring hollows, while still others take advantage of the voids left vacant by the more industrious previous occupants. Woodpeckers in particular are responsible for excavating many of the cavities that are later used as homes by a variety of birds and mammals to both rear their young and provide winter shelter. Pileated Woodpeckers, like other members of the family Picidae, have an almost mystic ability to locate diseased or insect-infested trees for selection as feeding and nesting sites. In this composite image, a pair is seen already working on a potential nursery during mid-January. After use by the woodpeckers, abandoned cavities of this size can become nesting sites for a variety of animals including bees, small owls, Great Crested Flycatchers, Wood Ducks, Hooded Mergansers, and squirrels.

Downy Woodpecker at Nest — After use as a nesting site, a void excavated by Downy Woodpeckers can be occupied in subsequent years by chickadees, titmice, nuthatches, wrens, and other cavity-dwelling species.

Muskrat with Leafy Twig — This Muskrat (*Ondatra zibethicus)* with a leafy twig in tow takes advantage of spring’s new growth to construct or repair its house,…

Muskrat House — A Muskrat house in March. In the absence of leafy twigs, dried cattail stems will suffice. As it ages and decays, the house’s organic matter generates heat and makes an ideal location for turtles to deposit and hatch their eggs.

Soon after Neotropical migrants begin arriving in the forests of the lower Susquehanna watershed, they begin constructing their nests. The majority of these species build “outdoors”, not within the confines of a tree cavity. Here we see a Wood Thrush with its bill full of dried leaves and other materials…

Wood Thrush Nest — …ready to line the cup of its nest in the fork of a small understory tree.

Though it often arrives during early April after spending the winter in sub-tropical and even some temperate climes, the Blue-gray Gnatcatcher must wait to start construction of its nest until many of the Neotropical migrants arrive in early May.

Blue-gray Gnatcatchers — Back at the nest site…

Baltimore Oriole with Nesting Material — Baltimore Orioles weave one the most unique nests of any species occurring in eastern North America.

Baltimore Oriole Nest — Unfortunately for them, man-made litter can often seem to be the ideal material for binding the nest together. In an area only sporadically visited by anglers, this oriole had no trouble finding lots of monofilament fishing line, trash that can fatally entangle both adult and young birds of any species. If you see any fishing line at all, please pick it up and dispose of it properly.

Baltimore Oriole — Always keep an eye open for fishing line and get it before the birds do!

Like many other avians, male Brown-headed Cowbirds are now relentlessly pursuing females of their kind.

Watching and waiting. The Indigo Bunting evades cowbird parasitism by first recognizing the invader’s egg. They then either add a new layer of nest lining over it or they abandon the nest completely and construct a new one. Some patient buntings may delay their breeding cycle until after cowbird courting behavior ceases in coming weeks.

March 17, 2025March 17, 2025

They Go Together Like Corned Beef and Cabbage

Find a stand of Common Cattails in a marsh, a stormwater basin, or along a pond edge right now and you’re almost certain to find a male Red-winged Blackbird …

September 11, 2023September 12, 2023

A Visit to a Beaver Pond

To pass the afternoon, we sat quietly along the edge of a pond created recently by North American Beavers (Castor canadensis). They first constructed their dam on this small stream about five years ago. Since then, a flourishing wetland has become established. Have a look.

A beaver lodge. — The beaver lodge was built among shrubs growing in shallow water in the middle of the pond.

Woolgrass in a beaver pond. — Woolgrass (Scirpus cyperinus) is a bulrush that thrives as an emergent and as a terrestrial plant in moist soils bordering the pond.

A male Common Whitetail dragonfly keeping watch over his territory.

A Twelve-spotted Skimmer perched on Soft Rush.

A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).

A Spicebush Swallowtail visiting Cardinal Flower. — A Spicebush Swallowtail visiting a Cardinal Flower.

A Green Heron looking for small fish, crayfish, frogs, and tadpoles.

A Green Heron stalks potential prey. — The Green Heron stalking potential prey.

A Wood Duck feeding on Lesser Duckweed. — A Wood Duck feeding on the tiny floating plant known as Lesser Duckweed (Lemna minor).

A Least Sandpiper feeding along the muddy edge of a beaver pond. — A Least Sandpiper poking at small invertebrates along the muddy edge of the beaver pond.

A Solitary Sandpiper testing the waters for proper feeding depth.

A Pectoral Sandpiper searches for its next morsel of sustenance.

A Sora rail in a beaver pond. — The Sora (Porzana carolina) is a seldom seen rail of marshlands including those created by North American Beavers. Common Cattails, sedges, and rushes provide these chicken-shaped wetland birds with nesting and loafing cover.

Isn’t that amazing? North American Beavers build and maintain what human engineers struggle to master—dams and ponds that reduce pollution, allow fish passage, and support self-sustaining ecosystems. Want to clean up the streams and floodplains of your local watershed? Let the beavers do the job!

April 19, 2023

Photo of the Day

Female Red-winged Blackbirds in a cattail wetland. — This year’s unseasonably mild weather has hastened the northward migration of many birds. Neotropical species including warblers and Broad-winged Hawks are already pushing through the lower Susquehanna region in numbers. But it seems the spring movement may be a little bit protracted for female Red-winged Blackbirds, which are still rolling through by the hundreds despite the males being here, some of them defending nesting territories, since late February. No sense of urgency?

March 9, 2023March 10, 2023

Off To The Races

Trying to get a favorable place to nest before others arrive, the “early birds” are presently racing north through the lower Susquehanna valley. Check out these sightings from earlier today…

Hooded Mergansers, two males and a female.

During these chilly days of late winter, this hardy Eastern Phoebe finds sustenance by seizing flying insects along the water’s edge.

An American Robin in classic worm-hunting posture. — Possibly our most familiar sign of spring, an American Robin in classic worm-hunting posture.

A Common Grackle in a maple tree that is starting to flower. — An iridescent Common Grackle in a maple tree that is beginning to flower.

A male Red-winged Blackbird singing near a small patch of cattails. — A male Red-winged Blackbird singing from a perch near a small patch of cattails. During the spring migration, noisy flocks of males compete for a breeding territory at these sites. Each of the victors defends his spot and awaits the arrival of a female mate while the losers move on to vie for their own breeding location farther north.

Time to get outside and have a look. The spectacle of spring migration passes quickly. You don’t want to miss it!

April 6, 2022April 7, 2022

Photo of the Day

Birds of Conewago Falls in the Lower Susquehanna River Watershed: American Bittern — The American Bittern (Botaurus lentiginosus) is a member of the Ardeidae, the heron and egret family. It is a stealthy migrant, making its flights under cover of darkness, then resting and feeding in dense stands of Common Cattails and other marsh plants during the day. It avoids detection by raising its bill skyward to create a profile and color scheme that blends well with the contours of the vegetation. In Pennsylvania, loss of wetland habitat used for nesting has led to the American Bittern being listed as an endangered species.

January 21, 2022August 15, 2022