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…




















LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED
A Natural History of Conewago Falls—The Waters of Three Mile Island
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…
After repeatedly hearing the songs of these Neotropical migrants from among the foliage, we were finally able to get a look at them—but it required persistent effort.
Sometimes we have to count ourselves lucky if we see just one in five, ten, or even twenty of the birds we hear in the cover of the forest canopy or thicket. But that’s what makes this time of year so rewarding for the dedicated observer. The more time you spend out there, the more you’ll eventually discover. See you afield!
Neotropical birds are fairly well acquainted with repetitive periods of thundershowers. With that in mind, we decided not to waste this stormy Tuesday by remaining indoors.
We hope you enjoyed our walk in the rain as much as we did. If you venture out on a similar excursion, please remember this. The majority of the wild animals around us have busy lives, particularly at this time of year. Most don’t take a day off just because it rains—that includes ticks.
As the Flowering Dogwoods remind us, it’s time for adult sea-run shad and other fishes to ascend the Susquehanna to spawn. So yep, we’re off to Fisherman’s Park on the river’s west shoreline below Conowingo Dam in Harford County, Maryland, to check it out.
Here’s a look at six native shrubs and trees you can find blooming along forest edges in the lower Susquehanna valley right now.
Local old timers might remember hearing folklore that equates the northward advance of the blooming of the Flowering Dogwoods with the progress of the American Shad’s spring spawning run up the river. While this is hardly a scientific proclamation, it is likely predicated on what had been some rather consistent observation prior to the construction of the lower Susquehanna’s hydroelectric dams. In fact, we’ve found it to be a useful way to remind us that it’s time for a trip to the river shoreline below Conowingo Dam to witness signs of the spring fish migration each year. We’re headed that way now and will summarize our sightings for you in days to come.
Despite what seemed to be a chilly early spring, the bright green leaves that unfold to close the canopy of our deciduous forests were dense and casting shade by the last days of April. For northbound migrants, this fresh foliage provides the cover they need for foraging, resting, and, for those that will stick around to breed in the lower Susquehanna valley, nesting.
We recall many occasions when sparse foliage during the first days of May seemed to delay the big push of Neotropical species, but the seasonal arrival of these birds in 2025 is thus far mostly ahead of schedule. This absence of delay is due in part to the lushness of the oaks. Some stands have not only leafed out, but are finished flowering and have added up to 12 inches of new branch growth. We spent these early hours of May among the oaks. Here’s a look at the Neotropical migrants and other species we found…
The movements of our migratory birds typically continue through much of the month of May. And peak numbers of Neotropical species often occur sometime during the second week of the month. But with habitat at the ready, favorable flight conditions could facilitate quick arrival and/or passage of the bulk of the remaining migrants during the coming week. You may want to venture out sooner rather than later—but watch your step!
During a warm spell back in late March, adult Mason Bees began emerging from nest sites to begin mating. During recent days, we photographed the fertile females as they continued the process that will produce the next generation of these fruit-friendly pollinators.
In early April of each year, we like to take a dreary-day stroll along the Susquehanna in Harrisburg to see if any waterfowl or seabirds have dropped in for a layover before continuing their journey from wintering waters along the Atlantic seaboard to breeding areas well to our north and northwest. As showers started to subside this Saturday morning past, here are some of the travelers we had the chance to see…
If you want a chance to see these seldom-observed visitors to the lower Susquehanna at Pennsylvania’s capital city, try a morning walk along mid-town’s Riverfront Park from Maclay Street to Forster Street. Also, try a stroll on City Island, particularly to the beach at the north end where you have a view of the mid-river areas upstream. To have better afternoon light, try the river’s west shore along Front Street in Wormleysburg from the Market Street Bridge upstream to Conodoguinet Creek. Once there, be certain to check the river from the Pennsylvania Fish and Boat Commission’s West Fairview Access Area at the mouth of the creek. And don’t be afraid to visit on a gloomy day; you never know what you might find!
SOURCES
Behrens, Ken, and Cameron Cox. 2013. Seawatching: Eastern Waterbirds in Flight. Houghton Mifflin Harcourt Publishing Company. New York, NY.
Soon after their arrival during the late 1600s, the earliest trans-Atlantic human migrants to settle the Lower Susquehanna River Watershed began the process of eliminating many of our largest native fish species. They started by extirpating nature’s steward of lowland streams and wetlands, the North American Beaver. The beaver’s meticulously maintained dams and fisheries-friendly ponds were promptly replaced by man-made impoundments designed to permanently divert water for powering lumber and grain mills. Behind these structures, silt deposits accumulated as the forests were clear cut and the land subjected to highly erosive farming methods. Mill dams would eventually be located on nearly every mile of suitable low-gradient stream in the basin. Populations of native coldwater fishes including Brook Trout were quickly lost or left isolated in scattered headwaters.
With their navigation of creeks blocked by nearly impenetrable mill dams, seasonally migratory freshwater and anadromous fish were denied access to their traditional spawning waters. The latter then had their populations seriously depleted, and in some cases extirpated, following construction of hydroelectric dams on the lower Susquehanna during the first half of the twentieth century. The loss these latter species, including the herrings, Striped Bass, and sturgeons, all of which attain great size only because of their ability to make a sea run to access the year-round food energy available in the Atlantic, constitute a tremendous reduction in the numbers, variety, and mass of fish occurring in the river and its tributaries.
Add to these events the various sources of pollution entering the lower Susquehanna’s waterways during the intervening years including acid mine drainage, agricultural nutrients and sediments, stormwater runoff, untreated domestic and industrial sewage, illegal dumping, pesticides, etc., and one can easily understand how the watershed’s native fishery was lost as a commercial, food, and recreational resource.
Presently, the effort to restore populations of self-sustaining anadromous fishes to the lower Susquehanna is stalled due to the presence of introduced invasive species, particularly Northern Snakeheads, in the river’s waters below Conowingo Dam. Lifts that carry migrating fishes over the lower river’s hydroelectric dams during the spring run are shut down to avoid extending the range of the hoards of non-native snakeheads to waters upstream of their present location. Any translocation of anadromous fish must now be completed by manually separating desired species from among the invaders and loading them into a tank truck for transport to waters upstream of the dams. But Northern Snakeheads are currently so prevalent at Conowingo that they are overwhelming the lift used for collecting and sorting fish as well.
Any slight hope that had existed for a return of harvestable stocks of American Shad or other sea-run native species to the Susquehanna and its tributaries seems to be fading. And widespread improvements to water quality that would promote reestablishment of sustained populations of native coldwater fishes like Brook Trout are strictly a long-range goal.
Recreational anglers, however, still remain in the game—but their reward is a bit of a booby prize. To compensate fisherman for the loss of their quarry on the river and in streams, and to promote an interest in the fishing pastime and conserving waterways, the stocking of various species of “game fish” has been a continuous undertaking, particular since the middle decades of the twentieth century. Some of these introductions are planned, others, like the release of Northern Snakeheads, are unsanctioned and outright illegal. The one thing most introductions have in common is that they consist of hardy, aggressive, predatory fishes that are non-native species (or native transplants from watersheds such as the Mississippi). Their presence, especially in large concentrations and particularly during the time immediately following introduction, can have a deleterious impact on native stream inhabitants. Some introduced fish, the Flathead Catfish for example, are upon discovery deemed invasive species; others, like the Smallmouth Bass, escape such a label not because they lack negative impacts on stream communities and ecosystems, but because they have been present for extended periods of time and have thus been accepted as part of the local fishing culture.
The creation of recreational fisheries comprised of introduced species has certainly helped maintain an interest in the fishing hobby and in the conservation of waterways. It has even been a driving force for spectacular restorations of streams that otherwise would have languished in an impaired condition with little in the way of diversity of species—native or non-native. As anglers, we are especially indebted to those who’ve devoted their time, energies, and, in some cases, a lot of money to projects that specifically seek to reestablish native waterways within the challenging landscape of the Lower Susquehanna River Watershed. With an eye on the future, perhaps now is a good time to join them and focus our passion for freshwater angling on steering fisheries management more toward the native ecosystems approach. Quality instead of quantity.
In that spirit, here are three items we can add to our tackle boxes this season to be better fisheries conservationists, instead of our own worst enemies.
Best of luck this fishing season. We hope your time outdoors will motivate you to get involved with efforts to keep your local waterways clean. You might even be inspired to assist with projects that are planned or currently underway in the Lower Susquehanna River Watershed to restore stream segments, wetlands, and floodplains. Many of these projects are grassroots efforts and they’d love to have your participation. Your local county conservation district can steer you towards an active restoration group near you. Give them a ring.
During Saturday’s Prescribed Fire Demonstration at the Pennsylvania Game Commission’s Middle Creek Wildlife Management Area, we noticed just how fast some species of wildlife return to areas subjected to burns administered to maintain grassland habitat and reduce the risk of high-intensity blazes.
Following the Prescribed Fire Demonstration, we decided to pay a visit to some of the parcels where burns had been administered one week earlier on the north side of Middle Creek’s main impoundment. We found a surprising amount of activity.
By late winter, sunshine and warming temperatures awaken the sleeping maples of the lower Susquehanna basin and the sap begins to flow. The new growing season is evident by the first days of spring when their swelling buds and flowers paint the drab gray canopy of deciduous woodlands with an overlying coat of red, orange, and maroon.
With relative humidity readings regularly dipping below 50%, the sunny days of March and early April are often some of the driest of the year. During recent weeks, these measurements have plunged to as low as 20%, levels not often observed in our region. As we’ve seen throughout the lower Susquehanna valley, windy weather and this extraordinarily dry air conspire to create optimal conditions for fast-spreading and often dangerous wildland fires.
On the brighter side, dry weather also provides the opportunity for foresters and other land managers to administer prescribed fire. These controlled burns are thoroughly planned to reduce accumulations of wildfire fuels and invigorate understory growth in forests. Their use also provides a number of effective methods for creating and maintaining wildlife habitats in non-forested areas.
This Saturday, March 22, 2025, crews from the Pennsylvania Game Commission will be hosting a Prescribed Fire Demonstration at Middle Creek Wildlife Management Area in Lancaster/Lebanon Counties. The event begins at 10:00 AM in the refuge’s museum/visitor’s center parking area. A controlled burn to “reset” a parcel with early successional growth back to grassland will follow a presentation on prescribed fire uses, planning, safety, and implementation.
Don’t forget: Middle Creek Wildlife Management Area museum/visitor’s center parking lot on Saturday, March 22, 2025, at 10:00 AM. See you there!
It appears that spring has at last arrived. It’s time to have a look around!
Of the bird species that pass southbound through the lower Susquehanna valley during autumn, we can generally observe many of the surviving individuals as they return north during the spring. But there are numerous exceptions. One of them is Golden Eagles.
While the strong northwest winds of late autumn create ideal lift for migrating Golden Eagles along our linear ridges, they also tend to enhance the birds’ tendencies to “ridge hop” their way south, thus pushing many of them southeast from the main corridor of the eastern population’s route through the central Appalachian Mountains. Here in the lower Susquehanna region, we observe these vagabonds at our numerous hawk watches which happen to be located along the outer periphery of the birds’ primary flight path. It appears that a greater percentage of these wayward eagles tend to be younger, less-experienced birds than those seen passing hawk-counting stations in the central Appalachians. Lucky for us, we get to see more of the showy juvenile and immature Golden Eagles—at least during the fall season.
In the spring, southerly breezes and the urge to “ridge hop” in a northerly direction tend to concentrate Canada-bound migrating Golden Eagles along the northernmost ridges in their Appalachian flyway. To see them, we took a short drive up the Juniata River valley to the 90,000 acres of Rothrock State Forest and Tussey Mountain Hawk Watch. During our visit there earlier this week, gusty winds from the southwest brought us an opportunity to see the elusive northbound flights of some of the members of eastern North America’s population of Golden Eagles.
For more information on the region’s hawk watches and the birds you’ll see there, be certain to click the “Hawkwatchers Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page. And for a more detailed look at how to determine the age of Golden Eagles, particularly during the autumn migration, click the “Golden Eagle Aging Chart” tab at the top of this page.
We’ve seen worse, but this winter has been particularly tough for birds and mammals in the Lower Susquehanna River Watershed. Due to the dry conditions of late summer and fall in 2024, the wild food crop of seeds, nuts, berries, and other fare has been less than average. The cold temperatures make insects hard to come by. Let’s have a look at how some of our local generalist and specialist species are faring this winter.
Wildlife certainly has a tough time making it through the winter in the lower Susquehanna valley. Establishing and/or protecting habitat that includes plenty of year-round cover and sources of food and water can really give generalist species a better chance of survival. But remember, the goal isn’t to create unnatural concentrations of wildlife, it is instead to return the landscape surrounding us into more of a natural state. That’s why we try to use native plants as much as possible. And that’s why we try to attract not only a certain bird, mammal, or other creature, but we try to promote the development of a naturally functioning ecosystem with a food web, a diversity of pollinating plants, pollinating insects, and so on. Through this experience, we stand a better chance of understanding what it takes to graduate to the bigger job at hand—protecting, enhancing, and restoring habitats needed by specialist species. These are efforts worthy of the great resources that are sometimes needed to make them a success. It takes a mindset that goes beyond a focus upon the welfare of each individual animal to instead achieve the discipline to concentrate long-term on the projects and processes necessary to promote the health of the ecosystems within which specialist species live and breed. It sounds easier than it is—the majority of us frequently become distracted.
On the wider scale, it’s of great importance to identify and protect the existing and potential future habitats necessary for the survival of specialist species. And we’re not saying that solely for their benefit. These protection measures should probably include setting aside areas on higher ground that may become the beach intertidal zone or tidal marsh when the existing ones become inundated. And it may mean finally getting out of the wetlands, floodplains, and gullies to let them be the rain-absorbing, storm-buffering, water purifiers they spent millennia becoming. And it may mean it’s time to give up on building stick structures on tinderbox lands, especially hillsides and rocky outcrops with shallow, eroding soils that dry to dust every few years. We need to think ahead and stop living for the view. If you want to enjoy the view from these places, go visit and take plenty of pictures, or a video, that’s always nice—then live somewhere else. Each of these areas includes ecosystems that meet the narrow habitat requirements of many of our specialist species, and we’re building like fools in them. Then we feign victimhood and solicit pity when the calamity strikes: fires, floods, landslides, and washouts—again and again. Wouldn’t it be a whole lot smarter to build somewhere else? It may seem like a lot to do for some specialist animals, but it’s not. Because, you see, we should and can live somewhere else—they can’t.
Our procrastinating groundhog
Susquehanna Stew
Is out to have a look around
Eight days overdue
Nibbling on some morsels
Basking in the sun
Almost three months since his last meal
Gee, that must be fun
But eating dried-up grasses
Might not do the trick
He might start feeling woozy
Or even getting sick
All this nonstop grazing
Stew’s just like a cow
He needs to find a way to stop
And end this binge right now
So when he saw his shadow
He knew just what to do
Time to head down under
‘Til wintertime is through
This crazy superstition
Sure did take its toll
The situation’s urgent
He’s headed for his hole
But Stew’s no fan of digging
Or all that woodchuck hype
This marmot has no burrow
His home’s a broken pipe
So if you want to see him
In springtime when it rains
Keep an eye on the clover field
Outside the flooding drains
Always a great time Stew. See you in the spring. And remember, it’s never a good idea to be late for dinner, so stay away from the carrots, celery, potatoes, and onions—someone may get the wrong idea!
As it turns out, 2024 was a big year for Bald Eagles—being officially named the national bird and all. You may be surprised to learn that the ringing in of a new year brings with it a new age class designation for all non-adult eagles. Sound confusing? No need to worry. We were fortunate enough to get pictures of about half of the Bald Eagles we happened to see in the lower Susquehanna valley earlier today, so we thought it only proper to share with you both the images and an explanation.
That’s a wrap, and that’s it for 2024. Have a Happy New Year! See you in 2025.
In addition to the Canada Geese and Snow Geese currently visiting Middle Creek Wildlife Management Area, three smaller geese of interest were seen there this afternoon.
There you have it, the three little geese—a Ross’s and two Cackling. They’re among North America’s smallest of the geese species and seldom are they seen so close together.
Our outing at Middle Creek Wildlife Management Area was today highlighted by teasing views of glistening white geese and swans—the tundra breeders that by February will create a sensation attracting thousands of birders, photographers, and other visitors to the refuge.
The Ross’s Goose (Anser rossii) is a rare but regular transient in the Lower Susquehanna River Watershed. This species nests in the arctic tundra of northernmost central Canada and winters in the valleys of California and in parts of Texas, Louisiana, and Arkansas, primarily near the northwestern rim of the Gulf of Mexico. A population also spends the colder months in western Texas, New Mexico, and an adjacent portion of north-central Mexico. The Ross’s Goose looks like a tiny version of a Snow Goose and is most often detected among flocks of these latter birds during their late winter visits to our area. Finding a single Ross’s Goose among thousands of Snow Geese can oft times be an insurmountable challenge, so it’s nice when one decides to drop by in a crowd within which it is much more discernible.
In case you were wondering—yes, despite the ice on Middle Creek’s lake, the Sandhill Cranes are still being seen in the vicinity of Willow Point.