LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED
A Natural History of Conewago Falls—The Waters of Three Mile Island
At last, the bird migration is picking up where it left off after the third week of September when rain, fog, and gloom arrived for a two week stay in the lower Susquehanna valley. Now that this persistent meteorological interluder has departed the stage, our stalled avians can resume the autumn spectacle.
Yesterday morning’s fallout of hundreds of nocturnally migrating birds was followed overnight by the influx of one hundred or more new arrivals atop Second Mountain in Lebanon County, Pennsylvania. Visitors to the forest clearing used as a hawk watch lookout were treated to the antics of these colorful Neotropical species and more…
These night-flying warblers, vireos, and flycatchers did again provide a thrilling show during the hours after sunrise, but today’s rarity passed through among the hundreds of migrating diurnal raptors—the tropics-bound Broad-winged Hawks—that made their way down the ridges of the lower Susquehanna valley this afternoon.
The peak of the autumn Broad-winged Hawk migration will likely occur during the coming two weeks with many counting stations tallying more than one thousand birds on the best of days. Visit one of these prominent lookout points so that you too can witness this amazing spectacle. Click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page to find a hawk watch near you!
Bathed in glowing sunshine, a very large fallout of migrating Neotropical songbirds enlivened the forest edge atop Second Mountain in northern Lebanon County, Pennsylvania, this morning. While last night’s flight was widespread beneath a dome of atmospheric high pressure covering the Mid-Atlantic States, this is a look at some of the 500 -1,000 migrants observed feeding on insects and other natural foods at just this single location.
Many of the observers at the Second Mountain Hawk Watch commented that this morning’s fallout was by far the best they had seen anywhere in the region during recent years. Others believed it to be the best they had ever seen. It was indeed less like a “wave” of migrants and more like a “tsunami”. Choosing a good viewing location and being there at the right time can improve your chances of seeing a spectacle like this. The good news is, it looks like another big flight is currently underway, so finding a forest edge on a ridgetop or along a utility right-of-way just might pay off for you early tomorrow morning.
Clear, cool nights have provided ideal flight conditions for nocturnal Neotropical migrants and other southbound birds throughout the week. Fix yourself a drink and a little snack, then sit down and enjoy this set of photographs that includes just some of the species we found during sunrise feeding frenzies atop several of the Lower Susquehanna River Watershed’s ridges. Hurry up, because here they come…
The migration is by no means over; it has only just begun. So plan to visit a local hawkwatch or other suitable ridgetop in coming weeks. Arrive early (between 7 and 8 AM) to catch a glimpse of a nocturnal migrant fallout, then stay through the day to see the hundreds, maybe even thousands, of Broad-winged Hawks and other diurnal raptors that will pass by. It’s an experience you won’t forget.
Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing south through the lower Susquehanna valley in coming months. And don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you.
The tiny flycatchers of the genus Empidonax are notoriously difficult to identify by visual clues alone. Determining the species by sight requires a good look under ideal conditions. Even then, these birds are a tricky lot. Don’t believe it? Take a gander at these photos of an Empidonax flycatcher found atop Second Mountain in Lebanon County at sunrise this morning…
It’s hard to believe, but for almost two months now, sandpipers, plovers, and terns have been filtering south through the Lower Susquehanna River Watershed on their way to the Atlantic coastline as they complete the first leg of their long autumn migration—a journey that will take some species all the way to the far reaches of the South American continent for winter.
As August draws to a close, these early birds are being joined by widespread nocturnal flights of Neotropical migrants—those species, primarily songbirds, on their way to wintering grounds which lie exclusively south of the continental United States.
To catch a glimpse of these night-flying avians, your best bet may be to position yourself on the crest of a ridge or along a linear break in the forest such as a utility right-of-way where waves of warblers, vireos, flycatchers, and other Neotropical passerines sometimes feed on invertebrates after making landfall at daybreak. Pick a place where the trees are bathed in the warm light of the rising sun and be there by 7 A.M. E.D.T. The activity can be tremendous, but it usually ends between 8 and 9.
Diurnal migrants, birds that make their movements during the daylight hours, are ramping up their flights now as well. Broad-winged Hawks, Bald Eagles, and falcons are currently being tallied at hawk-counting stations throughout the northeast. Many of those lookouts are seeing Ruby-throated Hummingbirds, swallows, and other daytime migrants too.
Autumn migration flights are an ever-changing process, with different species peaking at different times throughout the season. In these months just after the nesting season, each of these species is more numerous than at any other time of the year. And of course, the more often we as observers get out and have a look, the more of them we’ll see.
Be certain to click the “Birds” tab at the top of this page for a photo guide to the species you’re likely to see passing through the lower Susquehanna valley this fall. Nearly four months of autumn hawk migration flights lie ahead, so don’t forget to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab to find a hawk-counting station near you, then stop by for a visit or two. See you there!
You’ve probably never noticed the Acadian Flycatcher (Empidonax virescens). This small Neotropical songbird arrives in the Lower Susquehanna River Watershed during mid-May to breed in the dense shade of mature forests, often along steep slopes adjacent to a brook or creek. It’s quick, sneezy song—“pit-see” or “wee-seet”—heard emanating from the shadows of the woodland understory is often the first and only sign of their presence.
One of the more fascinating habits of the Acadian Flycatcher is their selection of a nesting location. While many species try to conceal their nests in tree cavities, dense foliage, or some other form of cover, this clever songbird constructs a cup using tiny twigs and leaves and places it near the end of a small branch on a small tree. The nest is sometimes very easily seen, but for climbing scroungers looking to plunder eggs or helpless young birds, it’s practically out of reach.
To guard against airborne threats, Acadian Flycatcher parents are vigilant defenders of the space around their nest.
Moments later, things settle down and the waiting continues…
During the past week, we’ve been exploring wooded slopes around the lower Susquehanna region in search of recently arrived Neotropical birds—particularly those migrants that are singing on breeding territories and will stay to nest. Coincidentally, we noticed a good diversity of species in areas where tent caterpillar nests were apparent.
Here’s a sample of the variety of Neotropical migrants we found in areas impacted by Eastern Tent Caterpillars. All are arboreal insectivores, birds that feed among the foliage of trees and shrubs searching mostly for insects, their larvae, and their eggs.
In the locations where these photographs were taken, ground-feeding birds, including those species that would normally be common in these habitats, were absent. There were no Gray Catbirds, Carolina Wrens, American Robins or other thrushes seen or heard. One might infer that the arboreal insectivorous birds chose to establish nesting territories where they did largely due to the presence of an abundance of tent caterpillars as a potential food source for their young. That could very well be true—but consider timing.
So why do we find this admirable variety of Neotropical bird species nesting in locations with tent caterpillars? Perhaps it’s a matter of suitable topography, an appropriate variety of native trees and shrubs, and an attractive opening in the forest.
Here in the Lower Susquehanna River Watershed, the presence of Eastern Tent Caterpillar nests can often be an indicator of a woodland opening, natural or man-made, that is being reforested by Black Cherry and other plants which improve the botanical richness of the site. For numerous migratory Neotropical species seeking favorable places to nest and raise young, these regenerative areas and the forests surrounding them can be ideal habitat. For us, they can be great places to see and hear colorful birds.
As waves of wet weather persistently roll through the Lower Susquehanna River Watershed, the tide of northbound migrants continues. Here are few of today’s highlights…
In recent days, the peak northbound push of migratory birds that includes the majority of our colorful Neotropical species has been slowed to a trickle by the presence of rain, fog, and low overcast throughout the Mid-Atlantic States. Following sunset last evening, the nocturnal flight resumed—only to be grounded this morning during the pre-dawn hours by the west-to-east passage of a fast-moving line of strong thundershowers. The NOAA/National Weather Service images that follow show the thunderstorms as well as returns created by thousands of migrating birds as they pass through the Doppler Radar coverage areas that surround the lower Susquehanna valley.
Just after 4 A.M., flashes of lightning in rapid succession repeatedly illuminated the sky over susquehannawildlife.net headquarters. Despite the rumbles of thunder and the din of noises typical for our urban setting, the call notes of nocturnal migrants could be heard as these birds descended in search of a suitable place to make landfall and seek shelter from the storm. At least one Wood Thrush and a Swainson’s Thrush (Catharus ustulatus) were in the mix of species passing overhead. A short time later at daybreak, a Great Crested Flycatcher was heard calling from a stand of nearby trees and a White-crowned Sparrow was seen in the garden searching for food. None of these aforementioned birds is regular here at our little oasis, so it appears that a significant and abrupt fallout has occurred.
Looks like a good day to take the camera for a walk. Away we go!
There’s obviously more spring migration to come, so do make an effort to visit an array of habitats during the coming weeks to see and hear the wide variety of birds, including the spectacular Neotropical species, that visit the Lower Susquehanna River Watershed each May. You won’t regret it!
What was the attraction that prompted dozens of birders to hike more than a mile to a secluded field edge along the Northwest Lancaster County River Trail on this last full day of autumn? It must be something good.
Indeed it was. A Western Flycatcher (Empidonax difficilis), first discovered late last week, has weathered the coastal storm that in recent days pummeled the Lower Susquehanna River Watershed with several inches of rain and blustery winds. Western Flycatchers nest in the Rocky Mountain and Pacific Coast regions of North America. They spend their winters in Mexico. There are several records of these tiny passerines in our area during December. The first, a bird found in an area known as Tanglewood during the Southern Lancaster County Christmas Bird Count (CBC) on December 16, 1990, was well documented—photographs were taken and its call was tape recorded. It constituted the first record of a member of the Western Flycatcher’s “Pacific-slope” subspecies group ever seen east of the Mississippi River. It was reported through December 26, 1990. The Tanglewood flycatcher and a bird sighted years later on a subsequent “Solanco CBC” were both found inhabiting wooded thickets in the shelter of a ravine created by one of the Susquehanna’s small tributaries.
How long will this wandering rarity remain along the river trail? For added sustenance, sunny days throughout the coming winter offer ever-increasing chances of stonefly hatches on the adjacent river, particularly in the vicinity of the stone bridge piers. But ultimately, the severity of the weather and the bird’s response to it will determine its destiny.
“Waves” of warblers and other Neotropical songbirds continue to roll along the ridgetops of southern Pennsylvania. The majority of these migrants are headed to wintering habitat in the tropics after departing breeding grounds in the forests of southern Canada. At Second Mountain Hawk Watch, today’s early morning flight kicked off at sunrise, then slowed considerably by 8:30 A.M. E.D.T. Once again, in excess of 400 warblers were found moving through the trees and working their way southwest along the spine of the ridge. Each of the 12 species seen yesterday were observed today as well. In addition, there was a Northern Parula and a Canada Warbler. Today’s flight was dominated by Bay-breasted, Blackburnian, Black-throated Green, and Tennessee Warblers.
Other interesting Neotropical migrants joined the “waves” of warblers…
During the recent couple of mornings, a tide of Neotropical migrants has been rolling along the crests of the Appalachian ridges and Piedmont highlands of southern Pennsylvania. In the first hours of daylight, “waves” of warblers, vireos, flycatchers, tanagers, and other birds are being observed flitting among the sun-drenched foliage as they feed in trees along the edges of ridgetop clearings. Big fallouts have been reported along Kittattiny Ridge/Blue Mountain at Hawk Mountain Sanctuary and at Waggoner’s Gap Hawk Watch. Birds are also being seen in the Furnace Hills of the Piedmont.
Here are some of the 300 to 400 warblers (a very conservative estimate) seen in a “wave” found working its way southwest through the forest clearing at the Second Mountain Hawk Watch in Lebanon County this morning. The feeding frenzy endured for two hours between 7 and 9 A.M. E.D.T.
Not photographed but observed in the mix of species were several Black-throated Blue Warblers and American Redstarts.
In addition to the warblers, other Neotropical migrants were on the move including two Common Nighthawks, a Broad-winged Hawk, a Least Flycatcher (Empidonax minimus), and…
Then, there was a taste of things to come…
Seeing a “wave” flight is a matter of being in the right place at the right time. Visiting known locations for observing warbler fallouts such as hawk watches, ridgetop clearings, and peninsular shorelines can improve your chances of witnessing one of these memorable spectacles by overcoming the first variable. To overcome the second, be sure to visit early and often. See you on the lookout!
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY ELEVEN—May 31, 1983
“AOK Camp, Texas — 7 Miles S. of Kingsville”
“Went south to the 1st rest stop south of Sarita — No Tropical Parula. Lots of other birds. We added Summer Tanager and Lesser Goldfinch.”
The Sarita Rest Area along Route 77 was like a little oasis of taller trees in the Texas scrubland. We received reports from the birders we met yesterday at Falcon Dam that recently, Tropical Parula had been seen there. We searched the small area and listened carefully, but to no avail. For these warblers, nesting season was over. We were surprised to find Lesser Goldfinches in the trees. Back in 1983, the coastal plain of Texas was pretty far east for the species. Steve was a bit skeptical when we first spotted them, but once they came into plain view, he was a believer. I recall him finally exclaiming, “They are Lesser Goldfinches.” Summer Tanager was another wonderful surprise. Today, the Sarita Rest Area remains a stopping point for birders in south Texas. Both Lesser Goldfinch and Tropical Parula were seen there this spring.
After our roll of dice at the Sarita Rest Area, we continued south through the King Ranch en route back to Brownsville.
“Saw a Coyote on the way.”
“Took Steve to the airport and drove out to Boca Chica where Harold went swimming.”
The drive from Brownsville out Boca Chica Boulevard to the Gulf of Mexico passes through about 18 miles of the outermost flats of the river delta that is the Lower Rio Grande Valley. This area is of course susceptible to the greatest impacts from tropical weather, especially hurricanes. During our visit, we passed a small cluster of ranch houses about two or three miles from the beach. This was the village known as Boca Chica. Otherwise, the area was desolate and left to the impacts of the weather and to the wildlife.
The mouth of the Rio Grande, and thus the international border with Mexico, was and still is about two miles south of Boca Chica Beach. Before the construction of dams and other flood control measures on the river, the path of the Rio Grande through the alluvium deposits on this outer section of delta would vary greatly. Accumulations of eroded material, river flooding, tides, and storms would conspire to change the landscape prompting the river to seek the path of least resistance and change its course. Surrounding the segments of abandoned channel, these changes leave behind valuable wetlands including not only the resacas of the Lower Rio Grande Valley, but similar features in tidal sections of the outer delta. When left to function in their natural state, deltas manage silt and pollutants in the waters that pass through them using ancient physical, biological, and chemical processes that require no intervention from man.
Harold was determined to go for a swim in the Gulf of Mexico before boarding a flight home. We all liked the beach. Why not? You may remember trips to the shore in the summertime. Back in the pre-casino days, we used to go to Atlantic City, New Jersey, to visit Steel Pier. For the first three quarters of the twentieth century, Steel Pier was the Jersey Shore’s amusement park at sea. There were rides, food stands, arcades, daily concerts with big name acts, diving shows, and ballroom dances.
There were, back then, attractions at Steel Pier that were creatively promoted to give the visitor the impression that they were going to see something more profound or amazing than was was delivered. You know, things advertised to draw you in, but its not quite what you expected.
For example, there was an arcade game promising to show you a chicken playing baseball. Okay, I’ll bite. Turns out the chicken did too. You put your money in the machine and watched as the chicken came out and rounded the diamond eating poultry food as it was offered at each of the bases. Hmmm…to suggest that this was a chicken playing baseball seems like a bit of a stretch.
They had a diving bell there too. Wow! We’ll go below the waves and view the fish, octopi, and other sights through the water-tight windows while we descend to the ocean floor. You would pay to get inside, then they would lower the bell down through a hole in the pier. Once below the rolling surf, you would get to look at the turbid seawater sloshing around at the window like dirty suds in a washing machine. If you were lucky, some trash might briefly get stuck on the glass. To imply that this was a chance to see life beneath waves was B. S., and I don’t mean bathysphere.
Then there was a girl riding a diving horse. You would hike all the way to the end of the pier and watch the preliminary show with these divers plunging through a hole in the deck and into the choppy Atlantic below. They were very good, but no, we never saw Rodney Dangerfield do a “Triple Lindy” there. And then it was time for the finale. Wow, is that horse going to dive in the ocean? How do they get the horse back up on the pier? Forget it. Instead of that, they walked poor Mr. Ed up a ramp into a box, then the girl climbs on his back, the door opens, and she nudges Ol’ Ed to into a plunge followed by a thumping splash into a swimming pool on the deck. Not bad, but not what we were expecting. Since we had to walk almost a quarter of a mile out to sea to get there, they kinda led us to believe that the amazing equine was going to leap into the Atlantic—horse hockey!
Preceding all this fun was a guy back in the early 1930s, William Swan, who, in June 1931, flew a “rocket-powered plane” at Bader Field outside Atlantic City. The plane was actually a glider on which a rocket was fired producing about 50 pounds of thrust to boost it airborne after assistants got it rolling by pushing it. In newspaper articles and on newsreels afterward, he would promote the future of rocket planes carrying passengers across the ocean at 500 miles per hour. Using a glider equipped with pontoons for landing in the ocean, he promised to make several flights daily from Steel Pier. Those who came to see him may have, at best, watched him fire small rockets he had attached to his craft—little more.
What does all this have to do with Boca Chica Beach? It turn out two years later, William Swan is hyping a new innovation—a rocket-powered backpack. He’d demonstrate it during a skydiving exhibition at the Del-Mar Beach Resort, a cluster of 20 cabins and community buildings on Boca Chica Beach. According to his deceptive promotions, Swan would jump out of a plane and light flares as he fell. Then he’d ignite the backpack rocket and land on the shoreline in front of the crowd. The event was expected to draw 3,000 carloads of people. When the big day came, just over 1,000 cars showed up. The event was a bust and the weather was bad, cloudy with a mist over the gulf. During a break in the clouds, the pilot took Swan aloft. Swan ordered him out to sea and to 8,500 feet, a higher altitude than planned. Then he jumped. He dropped the flares, which didn’t then ignite, and neither did the rocket. He opened his chute at 6,000 feet and the crowd watched as Swan drifted into the mist offshore and was never seen again. There were rumors both that he used the stunt as a way to flee to Mexico to start a new life and that he had committed suicide. Others believed he died accidentally. To learn the full story of Billy Swan, check out The Rocketeer Who Never Was, by Mark Wade.
Forward fifty years to our visit to Boca Chica Beach. The Del-Mar Beach Resort, built in the 1920s as a cluster of 20 cabins and a ballroom, was gone. It was destroyed by a hurricane later in the same year Swan disappeared—1933. The resort, which was hoped would be the start of a seaside vacation city, never reopened. In 1983, we saw just a handful of beach goers and the birds, that’s it. One could look down to the south and see the area of the Rio Grande’s mouth and Mexico, but there were no structures of note. It was peaceful and alive with wildlife. We were sorry we didn’t have more time there.
“Here we added Least Tern, Brown Pelican and Sandwich Tern.”
Today, the Village of Boca Chica and Boca Chica Beach are the location of SpaceX’s South Texas Launch Facility. Those of the village’s ranch houses built in 1967 that have survived hurricane devastation over the years have been incorporated into the “Starbase” production and tracking facility. The launch pad and testing area is along the beach just behind the dunes at the end of Boca Chica Boulevard.
The latest launch, just more than a month ago, was the maiden flight of “Starship”, a 394-foot behemoth that is the largest rocket ever flown. The “Super Heavy Booster” first stage’s 33 Raptor engines produce 17.1 million pounds of thrust making Starship the most powerful rocket ever flown. See, things really are bigger in Texas.
Last month’s unmanned orbital test launch ended when the Starship spacecraft failed to separate at staging. As the booster section commenced its roll manuever to return to the launch pad, the entire assembly began tumbling out of control. It exploded and rained debris into the gulf along a stretch of the downrange trajectory.
Development of Starbase is opposed by many due to noise, safety, and environmental concerns. Boca Chica Boulevard (Texas Route 4) is frequently closed due to activity at the launch pad site, thus excluding residents and tourists from visiting the beach. With over 1,200 people already working at Starbase, demand for housing in the Brownsville area has increased. Some have accused SpaceX CEO Elon Musk of promoting gentrification of the area—running up housing prices to force out the lower-income residents. He has responded with a vision of a new city at Boca Chica, his “space port”.
Does history have an applicable lesson for us here? When Musk talks about going to the Moon and Mars, or ferrying a hundred people around the world on his Starship, is it just another Steel Pier-style deception? Is Musk a modern-day William Swan? A very talented marketer? Could be. And is the whole thing setting up a large-scale replay of the Del-Mar Beach Resort’s demise in 1933? Is building a city on the outer edges of a river delta asking for an outcome similar to the one suffered by New Orleans during Hurricane Katrina? It’s likely. After all, building on or near a beach, floodplain, or delta is a short-sighted venture to begin with. If the party doing the developing doesn’t suffer the consequences of defying the laws of nature, one of the poor suckers in the successive line of buyers and occupants will. This isn’t rocket science folks. Its weather, climate, and erosion, and its been altering coastlines, river courses, and the composition and distribution of life forms on this planet for millions of years. And guess what. These factors will continue to alter Earth for millions of years more after man the meddler is long gone. You’re not going to stop their effects, and you’re not going to escape their wrath by ignoring them. So if you’re smart, you’ll get out of their way and stay there!
Billy Swan was probably broke when he came to Boca Chica. He reportedly borrowed 20 bucks from the resort operator just to cover his personal expenses during his backpack rocket event. Elon Musk comes to Boca Chica with over 100 billion dollars and capital from other private investors to boot. Despite some obvious exaggerations about colonizing the Moon, Mars, and other celestial bodies, he just might be able to at least get people there for short-term visits. And that’s quite an accomplishment.
“Then took Harold to the airport. We left him at 3:30 and headed north on Route 77, got as far as Victoria. Had a flat on the way. Larry had the spare on in 10 minutes. We stopped at a picnic area for the nite, because we could not find the camping area.”
If we were going to have a flat, we had it at the right place. We were just outside Raymondville, Texas, at a newly constructed highway interchange. The wide, level shoulder allowed us to get the camper off to the side of the road in a safe place to jack it up and change the tire. Easy. We were thereafter homeward bound.
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY TEN—May 30, 1983
“Falcon Dam State Park, Texas”
“9:30 — Breakfast — The Pauraque sang all nite and the Mockingbird sang half the nite and interrupted my sleep.”
Before leaving the campground, we paid a final visit to the shores of the reservoir. We saw Anhinga and Little Blue Heron among the other water birds we had seen there previously.
“Now to the spillway again. We got lucky — A Green Kingfisher flew in and gave us great views. Cliff Swallows were plentiful. The Green Herons were fishing and so was a Kiskadee Flycatcher. Black Vultures were flying around. A Groove-billed Ani was very much in evidence.”
The little Green Kingfisher (Chloroceryle americana), after all the effort we finally saw one. It was just half the size of the Ringed Kingfisher we saw at the spillway one day earlier.
“Here we met Bill Graber from San Antonio. Ron and 3 women—Sandra from Wales, 1 from Oregon, and 1 from San Antonio… We all walked to the spot for the Ferruginous Owl”
We again followed Father Tom’s directions; “Park at spillway, walk the road to a fence, go right to the river, follow fence to a big dip (gully).”
Once in the designated area, several of us began searching around the vicinity for the owls. I was out of sight of the others and was examining a long procession of tropical leafcutter ants, possibly the Texas Leafcutter Ant (Atta texana). Their foraging trail had two single-file lanes—worker ants carrying dime-sized pieces of leaves to the nest and worker ants returning to the tree to harvest more. The ants’ path of travel stretched for more than one hundred feet down the limbs and trunk of the source tree, across the sandy ground, over a fallen log, across more sandy ground, through some leaf litter in the shrubs, and to the nest, where the foliage will be used to cultivate fungi (Lepiotaceae) for food. Thousands of worker ants were marching the route while others guarded their lines—fascinating.
Suddenly, I heard a commotion in the brush. Collared Peccaries (Dicotyles tajacu), also known as Javelina, on the run and headed right my way! The others must have unknowingly spooked them. In an instant I scrambled to my feet and bounded up the trunk of a willow tree that was strongly arching toward the river and had partially fallen after the bank had washed away. There I stood atop the nearly horizontal trunk as between 6 and 10 grunting peccaries bustled past in a cloud of dust. Just as fast as they had appeared, they were gone.
I walked back toward the gully and as I approached, I could see everyone peering at something in the dense foliage of the trees overhanging the river.
“…eventually Sandra spotted one coming in. Another was also seen in a much better position. We all saw the 2 black spots on the back of his head when he turned his head 180°. It looked like another face.”
They had found the Ferruginous Pygmy Owls, right where Father Tom said they would be. But they weren’t easy to see. And they were tiny. Make a loose fist—that’s about the size of a Ferruginous Pygmy Owl. We had to take turns standing at favorable places where there was a less-obstructed view of each bird. I’m not certain that anyone was able to get photographs. The shade was too dark for my equipment to get a favorable exposure. Such had been the case for many of the birds we found in the riparian forest. This owl was a life list species for everyone in our group and for most of the others. Like the Green Kingfisher, the owls were just barely within the A.B.A. area, on limbs stretching out above the waters of the Rio Grande.
“Then we came back to the picnic ground and walked the river’s edge for a 1/4 mile — Nothing extra, except an Altamira Oriole.”
I again did a little wading in the Rio Grande to cool down after spending hours in the hot scrubland/forest.
“On the way back to Brownsville, we stopped at Santa Margarita again with no Brown Jay luck.”
Though we never did bump into the roving band of Brown Jays at Santa Margarita Ranch, they were there, and they’re a species that’s still there today.
“On to Brownsville for good sightings of the Clay-colored Robin at the radio station.”
We returned to the radio transmitter site at Coria and Los Ebanos in Brownsville for yet another attempt to find Clay-colored Robins/Thrushes. After again securing permission from Mr. Wilson to have a look around, we at last had success and found a pair of Clay-colored Thrushes moving about in the boughs of the shade-casting tress and shrubs. With some persistence, we all got binocular views of these earth-tone rarities from Mexico.
While in Brownsville, we thought it a good idea to dabble a bit in the experiences of local consumer culture, so we drove downtown. After finding a place to park the camper, we commenced to going for an international stroll over the bridge that crosses the Rio Grande into Matamoras, Tamaulipas, Mexico. It was our first legal incursion south of the border. (In recent days, we may have stepped back-and-forth over the line a couple of times while wading in the river below Falcon Dam.)
Once in Matamoros, we entered the bank. Steve wanted to get some Mexican currency and coins for his collection, so we stepped inside. It was a typical classical-style masonry building like most banks built early in the twentieth century were, but this one had very few accoutrements inside. There was a big vault, some cash drawers, maybe a desk and a chair, and that was it. The doors were left open to get a flow of dirty air in the place because there was no air conditioning. No loan department or Christmas Clubs here, just dollars for pesos.
Upon leaving the bank and heading into the town, we were solicited by the unlicensed curbside pharmacists selling herbs and other home remedies. Not for me, I had one thing in mind on this shopping trip.
We walked up the street to step inside some of the numerous tourist shops—stuff everywhere. The other men bought a few post cards. For a friend back home, I bought a key chain with a tiny pair of cowboy boots attached. Having heard that cowboy boots could be had for cheap south of the border, he had given me his size requirements and asked that I should get him a pair if the price was right. Well, the price wasn’t that great in the tourist town section of the city, so I got him the key chain instead.
After about an hour, we were headed back over the bridge into Brownsville. Along the pedestrian walkway, there was a United States Customs checkpoint one had to pass before entering the country. The customs officer asked the usual questions and after telling him we were only in Mexico for an hour, he queried, “Did you buy anything that you’re bringing back into the country.” Having an item to declare, I told him yes, I bought a pair of cowboy boots. He looked down at my rubber-toed canvas sneakers, then looked at Russ, Harold, and Steve, who obviously weren’t carrying or wearing boots, and he snapped, “Where are they?” I pulled the wax paper bag with the key chain inside from my pocket. He called me a smart ass and waved us on. We chuckled.
The only bird species seen during or short trek into Matamoros? House Sparrow.
In the forty years since our visit to the Rio Grande Valley, the rate of northbound human migration across the river, and particularly the amount of smuggling activity that uses the migration as a diversion to cover its operations, has surely taken the fun out of being on the border. Many of the places we visited are no longer open to the public, or access is restricted and subject to tightened security. Santa Margarita Ranch, for example, now allows guided tours only. Falcon Dam changed its security practices after one of a pair of opposing drug cartels escalated their mutual dispute by planting explosives there—threatening to blow it up to hamper crossings by its opponent’s smugglers in the fordable waters downstream.
Fortunately for today’s birder, many of the tropical specialties have inched their range north of the Rio Grande’s banks and can be found on accessible public and private lands outside the immediate tension zone. National Wildlife Refuges and Texas State Parks provide access to some of the best habitats. Places like the King Ranch even offer guided bird and wildlife tours on portions of their vast holdings where many border species including Ferruginous Pygmy Owl, Crested Caracara (Caracara plancus), Green Jay, Vermillion Flycatcher (Pyrocephalus obscurus), Northern Beardless-Tyrannulet (Camptostoma imberbe), and the tropical orioles are now found. So don’t let the state of dysfunction on the border stop you from visiting south Texas and its marvelous ecosystems. It’s still a birder’s paradise!
“We ate supper at Luby’s Cafeteria and headed north on Route 77 for the Tropical Parula.”
Harold was very pleased to have added Hook-billed Kite, Ferruginous Pygmy Owl, and Clay-colored Thrush to his A.B.A. life list, so he offered to buy dinner. After visiting a mail box to get a few postcards on their way, we ate at Luby’s Cafeteria in Brownsville, which was an interesting experience for that time period. Luby’s was a regional restaurant chain. You could get in line there and select anything you wanted, then pay for it by the item. Luby’s predated the all-you-can-eat salad bar and buffet craze that would sweep the restaurant industry in coming years. Under the circumstances, it was perfect for us. After not eating much all week due to the hot, humid conditions that accompanied the unusually rainy weather, our appetites begged satisfaction—but the heat hadn’t relented, so we didn’t want to overdo it. The staff at Luby’s didn’t blink an eye at us entering the restaurant wearing field clothes. It was the first climate-controlled space we had enjoyed all week—very refreshing. We really enjoyed the experience and it recharged us all.
Near Raymondville along Route 77, a set of electric wires strung on tall wooden poles paralleled the highway. These poles were hundreds of yards away from road, but seeing a raptor atop one, we stopped and got out the spotting scope. It was yet another south Texas specialty, a White-tailed Hawk (Buteo albicaudalus), a bird of grassland and brush. Its range north of Mexico is limited to an area of Texas from the Lower Rio Grande Valley north through the King Ranch to just beyond Kingsville. A short while later, we saw one or two more on our way through the King Ranch.
“Saw a flock of White-rumped Sandpipers when we stopped for gas.”
Lest one might think that traveling through parts of five south Texas counties to go from Falcon Dam back east through the Lower Rio Grande Valley to Brownsville and then north for a return stay at the A.O.K. campground is just another day of birding punctuated by some driving every now and again, consider the mileage racked up on the odometer today—259 miles. Even the counties are bigger in Texas.
We topped off the fuel tank at a service station near Sarita, Texas, and saw the White-rumped Sandpipers (Calidris fuscicollis) in a pool of rainwater among the scrubland at roadside.
“We stopped at the AOK Camp Ground 7 miles south of Kingsville and will return to get the parula at the first rest stop south of Sarita. Now 9:30 CDST.”
WHY WORRY ABOUT SPIDERS AND SNAKES?
Back at the old A.O.K. campground, this time with Harold and Steve, we decided to have a camp fire for the first time on the trip. We bought a bundle of wood at the camp office and soon had it crackling. I broke out the harmonica, but knowing no cowboy tunes, soon stashed it away. We had better things to do. Did we bake some beans in an iron kettle on the hot embers? No, we ate plenty at Luby’s. Did we toast marshmallows on sticks and make s’mores? Nope. Did we roast our weenies and warm our buns? No, not that either. We simply sat around recapping our trip while scratching our itchy ankles. Seems each of us was hosting chigger larvae and these parasites, upon maturing to nymphs and departing, left irritating wounds in our skin where they had been feeding—right in the hollow of our ankles.
Chiggers (Trombiculidae), like spiders and ticks, are arachnids. They thrive in humid environments as opposed to arid climes. Our best guess was that we had picked them up while hiking around in the subtropical riparian forests along the Rio Grande in the early days of the trip. My wounds eventually left little red pimples where each tiny larva had been feeding. They healed about a week after I got home. Due to the severity of his wounds, Steve cancelled a second week of his trip. On his own, he was going to continue west along the Rio Grande to the area of Big Bend National Park, but instead booked a flight home. Chigger larvae are stealthy little sneaks—we never had any clue they got us until they were gone. So why worry about spiders and snakes?
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY FIVE—May 25, 1983
Bentsen State Park, Texas
Went to bed last nite about 11:30. Did not set the alarm. Very hot — Awoke at 7:30 A.M. We circled the campground and then drove to the river trail. We walked to the river, getting more lifers for Larry — Couch’s Kingbird, Olive Sparrow, and Groove-billed Ani. The Couch’s Kingbird is my first lifer of the trip. The Olive Sparrow has the same cadence as the Tennessee Warbler. We then checked the resaca and found a Least Bittern.
While checking out the cattails at the resaca, we failed to catch a glimpse of a Coues’ Rice Rat (Oryzomys couesi), a semi-aquatic mammal that lives only in the Rio Grande Valley and areas south into Central America. Instead we found an Eastern Fox Squirrel (Sciurus niger), a giant compared to the gray squirrels in Pennsylvania. Things really are bigger in Texas.
Back to our camp site for lunch, after paying for our stay at the office. P.M. — Put out corn and sunflower seeds and loafed all P.M. trying to get pictures. Larry had a lot of luck. I did not do so good.
Plain Chachalacas, White-winged Doves, White-tipped Doves, Great-tailed Grackles, and a Bronzed Cowbird stopped by to sample the seed offerings. The chachalacas and grackles created quite a racket. It’s a good thing we didn’t have any neighbors close by!
In nearby areas of the campground there were many species—Black-bellied Whistling Duck, Anhinga, Great Egret, Common Gallinule, Turkey Vulture, Yellow-billed Cuckoo, Golden-fronted Woodpecker, Ladder-backed Woodpecker, Eastern Kingbird, Brown-crested Flycatcher, Curve-billed Thrasher, Long-billed Thrasher (Toxostoma longirostre), Altamira Oriole, and Northern Cardinal.
Rain is rare here — The rainy season produced no rain. Now a light rain is falling. The temperature dropped to 90° in the camper. One couple wanted to see anis. Larry picked one out 50 ft. from their campsite.
The rain cooled the air to make the evening tolerable, but we would pay for it tomorrow with an increase in the humidity.
We paid for another nite and at dusk went to the Elf Owl tree where eventually 4 young came out and tried their wings and crawled around. The two adults flew in and Larry was ecstatic taking pictures with his strobe light. We met some people. One couple never saw Eastern Bluebirds. I gave him my card. Another couple pinpointed the owl tree.
This evening was certainly highlighted by the emergence of the young Elf Owls (Micrathene whitneyi) from their nest cavity. But in addition, we again heard the sounds of some of the other nocturnal birds found in the park—Common Nighthawk, Common Pauraque, and Eastern Screech Owl.
Back in late May of 1983, four members of the Lancaster County Bird Club—Russ Markert, Harold Morrrin, Steve Santner, and your editor—embarked on an energetic trip to find, observe, and photograph birds in the Lower Rio Grande Valley of Texas. What follows is a daily account of that two-week-long expedition. Notes logged by Markert some four decades ago are quoted in italics. The images are scans of 35 mm color slide photographs taken along the way by your editor.
DAY TWO—May 22, 1983
Our goal today was to continue traveling and reach western Louisiana.
“We were on our way at 6:08. Stopped for a quick lunch in the camper and drove to Vinton, Louisiana, KOA. Lots of hard rain through Tennessee, Georgia, and Alabama.
As we crossed Mississippi and entered Louisiana, we left the rain and the Appalachians behind. Upon crossing the Mississippi River, we had arrived in the West Gulf Coastal Plain, the physiographic province that extends all the way south along the Texas coast to Mexico and includes the Lower Rio Grande Valley. West of Baton Rouge, we began seeing waders in the picturesque Bald Cypress swamps—Great Egrets, Green Herons (Butorides virescens), Little Blue Herons (Egretta caerulea), and Glossy Ibis (Plegadis falcinellus) were identified. A Pileated Woodpecker was observed as it flew above the roadside treetops.
The rains we endured earlier in the trip had left there mark in much of Louisiana and Texas. Flooding in agricultural fields was widespread and the flat landscape often appeared inundated as far as the eye could see. Along the highway near Vinton, we spotted the first two of the many southern specialties we would find on the trip, a Loggerhead Shrike (Lanius ludovicianus) and a Scissor-tailed Flycatcher (Tyrannus forficatus), both perched on utility wires and searching for a meal.
For nearly a week now, a slow-moving low pressure system has not only brought heavy rain and cold temperatures to the northeastern United States, it has also stalled the northbound flights of migrating Neotropical birds. As this weather system at last drifts offshore, birds including warblers, thrushes, vireos, flycatchers, catbirds, hummingbirds, orioles, tanagers, and others should again resume their northward movements.
National Weather Service radar presently displays returns of these airborne nocturnal migrants in clear storm-free skies throughout the eastern half of the United States and Canada. As the showers and clouds depart the lower Susquehanna valley and areas to the north, the birds immediately to our south will begin to fill the void.
Our advice to you…plan to spend some time outdoors this weekend looking for our colorful Neotropical visitors. Their springtime songs should fill the warm air of forest and thicket. You won’t want to miss it.
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…
Time to get outside and have a look. The spectacle of spring migration passes quickly. You don’t want to miss it!
There’s something in the air tonight—and it’s more than just a cool comfortable breeze.
It’s a major nocturnal movement of southbound Neotropical birds. At daybreak, expect a fallout of migrants, particularly songbirds, in forests and thickets throughout the region. Warblers, vireos, flycatchers, thrushes, Scarlet Tanagers, and Rose-breasted Grosbeaks pass through in mid-September each year, so be on the lookout!
You’ll want to go for a walk this week. It’s prime time to see birds in all their spring splendor. Colorful Neotropical migrants are moving through in waves to supplement the numerous temperate species that arrived earlier this spring to begin their nesting cycle. Here’s a sample of what you might find this week along a rail-trail, park path, or quiet country road near you—even on a rainy or breezy day.
Thoughts of October in the Lower Susquehanna River Watershed bring to mind scenes of brilliant fall foliage adorning wooded hillsides and stream courses, frosty mornings bringing an end to the growing season, and geese and other birds flying south for the winter.
The autumn migration of birds spans a period equaling nearly half the calendar year. Shorebirds and Neotropical perching birds begin moving through as early as late July, just as daylight hours begin decreasing during the weeks following their peak at summer solstice in late June. During the darkest days of the year, those surrounding winter solstice in late December, the last of the southbound migrants, including some hawks, eagles, waterfowl, and gulls, may still be on the move.
During October, there is a distinct change in the list of species an observer might find migrating through the lower Susquehanna valley. Reduced hours of daylight and plunges in temperatures—particularly frost and freeze events—impact the food sources available to birds. It is during October that we say goodbye to the Neotropical migrants and hello to those more hardy species that spend their winters in temperate climates like ours.
The need for food and cover is critical for the survival of wildlife during the colder months. If you are a property steward, think about providing places for wildlife in the landscape. Mow less. Plant trees, particularly evergreens. Thickets are good—plant or protect fruit-bearing vines and shrubs, and allow herbaceous native plants to flower and produce seed. And if you’re putting out provisions for songbirds, keep the feeders clean. Remember, even small yards and gardens can provide a life-saving oasis for migrating and wintering birds. With a larger parcel of land, you can do even more.
The southbound bird migration of 2020 is well underway. With passage of a cold front coming within the next 48 hours, the days ahead should provide an abundance of viewing opportunities.
Here are some of the species moving through the lower Susquehanna valley right now.
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.
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.
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.
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!
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.
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.
Local birders enjoy going to the Atlantic coast of New Jersey and Delmarva in the winter. The towns and beaches host far fewer people than birds, and many of the species seen are unlikely to be found anywhere else in the region. Unusual rarities add to the excitement.
The regular seaside attraction in winter is the variety of diving ducks and similar water birds that feed in the ocean surf and in the saltwater bays. Most of these birds breed in Canada and many stealthily cross over the landmass of the northeastern United States during their migrations. If an inland birder wants to see these coastal specialties, a trip to the shore in winter or a much longer journey to Canada in the summer is normally necessary—unless there is a fallout.
Migrating birds can show up in strange places when a storm interrupts their flight. Forest songbirds like thrushes and warblers frequently take temporary refuge in a wooded backyard or even in a city park when forced down by inclement weather. Loons have been found in shopping center parking lots after mistaking the wet asphalt for a lake. Fortunately though, loons, ducks, and other water birds usually find suitable ponds, lakes, and rivers as places of refuge when forced down. For inland birders, a fallout like this can provide an opportunity to observe these coastal species close to home.
Not so coincidentally, it has rained throughout much of today in the Lower Susquehanna River Watershed, apparently interrupting a large movement of migrating birds. There is, at the time of this writing, a significant fallout of coastal water birds here. Hundreds of diving ducks and other benthic feeders are on the Susquehanna River and on some of the clearer lakes and ponds in the region. They can be expected to remain until the storm passes and visibility improves—then they’ll promptly commence their exodus.
The following photographs were taken during today’s late afternoon thundershower at Memorial Lake State Park at Fort Indiantown Gap, Lebanon County.
Migrating land birds have also been forced down by the persistent rains.
Why not get out and take a slow quiet walk on a rainy day. It may be the best time of all for viewing certain birds and other wildlife.
Inside the doorway that leads to your editor’s 3,500 square foot garden hangs a small chalkboard upon which he records the common names of the species of birds that are seen there—or from there—during the year. If he remembers to, he records the date when the species was first seen during that particular year. On New Year’s Day, the results from the freshly ended year are transcribed onto a sheet of notebook paper. On the reverse, the names of butterflies, mammals, and other animals that visited the garden are copied from a second chalkboard that hangs nearby. The piece of paper is then inserted into a folder to join those from previous New Year’s Days. The folder then gets placed back into the editor’s desk drawer beneath a circular saw blade and an old scratched up set of sunglasses—so that he knows exactly where to find it if he wishes to.
A quick glance at this year’s list calls to mind a few recollections.
Before putting the folder back into the drawer for another year, the editor decided to count up the species totals on each of the sheets and load them into the chart maker in the computer.
Despite the habitat improvements in the garden, the trend is apparent. Bird diversity has not cracked the 50 species mark in 6 years. Despite native host plants and nectar species in abundance, butterfly diversity has not exceeded 10 species in 6 years.
It appears that, at the very least, the garden habitat has been disconnected from the home ranges of many species by fragmentation. His little oasis is now isolated in a landscape that becomes increasingly hostile to native wildlife with each passing year. The paving of more parking areas, the elimination of trees, shrubs, and herbaceous growth from the large number of rental properties in the area, the alteration of the biology of the nearby stream by hand-fed domestic ducks, light pollution, and the outdoor use of pesticides have all contributed to the separation of the editor’s tiny sanctuary from the travel lanes and core habitats of many of the species that formerly visited, fed, or bred there. In 2019, migrants, particularly “fly-overs”, were nearly the only sightings aside from several woodpeckers, invasive House Sparrows (Passer domesticus), and hardy Mourning Doves. Even rascally European Starlings became sporadic in occurrence—imagine that! It was the most lackluster year in memory.
If habitat fragmentation were the sole cause for the downward trend in numbers and species, it would be disappointing, but comprehendible. There would be no cause for greater alarm. It would be a matter of cause and effect. But the problem is more widespread.
Although the editor spent a great deal of time in the garden this year, he was also out and about, traveling hundreds of miles per week through lands on both the east and the west shores of the lower Susquehanna. And on each journey, the number of birds seen could be counted on fingers and toes. A decade earlier, there were thousands of birds in these same locations, particularly during the late summer.
In the lower Susquehanna valley, something has drastically reduced the population of birds during breeding season, post-breeding dispersal, and the staging period preceding autumn migration. In much of the region, their late-spring through summer absence was, in 2019, conspicuous. What happened to the tens of thousands of swallows that used to gather on wires along rural roads in August and September before moving south? The groups of dozens of Eastern Kingbirds (Tyrannus tyrannus) that did their fly-catching from perches in willows alongside meadows and shorelines—where are they?
Several studies published during the autumn of 2019 have documented and/or predicted losses in bird populations in the eastern half of the United States and elsewhere. These studies looked at data samples collected during recent decades to either arrive at conclusions or project future trends. They cite climate change, the feline infestation, and habitat loss/degradation among the factors contributing to alterations in range, migration, and overall numbers.
There’s not much need for analysis to determine if bird numbers have plummeted in certain Lower Susquehanna Watershed habitats during the aforementioned seasons—the birds are gone. None of these studies documented or forecast such an abrupt decline. Is there a mysterious cause for the loss of the valley’s birds? Did they die off? Is there a disease or chemical killing them or inhibiting their reproduction? Is it global warming? Is it Three Mile Island? Is it plastic straws, wind turbines, or vehicle traffic?
The answer might not be so cryptic. It might be right before our eyes. And we’ll explore it during 2020.
In the meantime, Uncle Ty and I going to the Pennsylvania Farm Show in Harrisburg. You should go too. They have lots of food there.
One can get a stiff neck looking up at the flurry of bird activity in the treetops at this time of year. Many of the Neotropical migrants favor rich forests as daytime resting sites after flying through the night. For others, these forests are a destination where they will nest and raise their young.
For the birds that arrive earlier in spring than the Neotropical migrants, the breeding season is well underway. The wet weather may be impacting the success of the early nests.
So long for now, if you’ll excuse me please, I have a sore neck to tend to.
The humid rainy remains of Hurricane Nate have long since passed by Pennsylvania, yet mild wet weather lingers to confuse one’s sense of the seasons. This gloomy misty day was less than spectacular for watching migrating birds and insects, but some did pass by. Many resident animals of the falls are availing themselves of the opportunity to continue active behavior before the cold winds of autumn and winter force a change of lifestyle.
Warm drizzle at daybreak prompted several Northern Spring Peepers (Pseudacris crucifer crucifer) to begin calling from the wetlands in the Riparian Woodlands of Conewago Falls. An enormous chorus of these calls normally begins with the first warm rains of early spring to usher in this tiny frog’s mating season. Today, it was just a few “peeps” among anxious friends.
Any additional river flow that resulted from the rains of the previous week is scarcely noticeable among the Pothole Rocks. The water level remains low, the water column is fairly clear, and the water temperatures are in the 60s Fahrenheit.
It’s no real surprise then to see aquatic turtles climbing onto the boulders in the falls to enjoy a little warmth, if not from the sun, then from the stored heat in the rocks. As usual, they’re quick to slide into the depths soon after sensing someone approaching or moving nearby. Seldom found anywhere but on the river, these skilled divers are Common Map Turtles (Graptemys geographica), also known as Northern Map Turtles. Their paddle-like feet are well adapted to swimming in strong current. They are benthic feeders, feasting upon a wide variety of invertebrates found among the stone and substrate of the river bottom.
Adult Common Map Turtles hibernate communally on the river bottom in a location protected from ice scour and turbulent flow, often using boulders, logs, or other structures as shelter from strong current. The oxygenation of waters tumbling through Conewago Falls may be critical to the survival of the turtles overwintering downstream. Dissolved oxygen in the water is absorbed by the nearly inactive turtles as they remain submerged at their hideout through the winter. Though Common Map Turtles, particularly males, may occasionally move about in their hibernation location, they are not seen coming to the surface to breathe.
The Common Map Turtles in the Susquehanna River basin are a population disconnected from that found in the main range of the species in the Great Lakes and upper Mississippi basin. Another isolated population exists in the Delaware River.
SOURCES
Committee on the Status of Endangered Wildlife in Canada. 2002. Status Report of the Northern Map Turtle. Canadian Wildlife Service. Ottawa, Ontario.