As we enter November, migratory raptor flights through the Lower Susquehanna River Watershed transition to the bigger birds. Whether you’re on the river, on a mountain, or just outside your humble abode, persistent alertness to soaring avians can yield rewarding views of a number of late-season specialties.
Red-tailed Hawks dominate the southbound raptor flights in November.Juvenile (hatch-year) Red-tailed Hawks are generally less wary and more inquisitive than the more experienced adult birds. Their curiosity frequently gets them into trouble, particularly when they try to hunt small rodents in traffic along busy roadways.Far fewer in number are migratory Red-shouldered Hawks. In our region, these denizens of bottomland forests more commonly migrate along the southern edge of the Piedmont and through the upper Atlantic Coastal Plain.A southbound hatch-year (juvenile) Red-shouldered Hawk.Mixed-race Peregrine Falcons, the descendants of birds reintroduced into the Mid-Atlantic States during the late twentieth century, often roam our region during the late-fall and winter months before settling into their nesting territories with the approach of spring. We spotted this one along a local ridge, but you may be more likely to see them in the city or near a bridge or dam on the river.As this adult peregrine passed the lookout, we noted its full crop. A sign it just completed a successful hunt.
A visit to a ridgetop on a breezy day—particularly after passage of a cold front—may give you the chance to see numerous eagles as well.
A second-year (Basic I) Bald Eagle barrel rolls while pursuing an adult Bald Eagle.
This afternoon, we got lucky and were treated to a bit of an aging clinic presented by the Bald Eagles we observed and photographed. Careful determination of the age classes of raptors counted by hawkwatchers can provide an early warning of problems in the ecosystems that support populations of these top-of-the-food-chain predators. For example: during the 1950s and early 1960s, a progressively lower percentage of juvenile and other non-adult age classes among the Bald Eagles being observed forewarned of the dangers of dichlorodiphenyltrichloroethane (DDT) pesticide in the environment. The principle effect of accumulations of the DDT toxins in eagles, Ospreys, Peregrine Falcons, and other predatory birds that consumed waterfowl and/or fish was to thin their eggs shells. The result was widespread brood failure and a near total loss of new generations of offspring. Eventually, nearly all Bald Eagles being seen in areas impacted by DDT were progressively older adults, most of which failed as nesting pairs. As the adult birds began dying off, the Bald Eagle population dwindled to numbers that raised fears of the species’ extinction. Implementation of the DDT cancellation order and the Clean Water Act in 1972, and the Endangered Species Act in 1973, helped save the Bald Eagle. But our regional “Eastern Peregrine Falcon”, a bird with a shorter life span than the Bald Eagle, was unable to endure the years of DDT use, dioxin pollution, and illegal hunting and egg collecting. Its population is gone.
A hatch-year (juvenile) Bald Eagle is typically dark headed and in a fresh set of juvenile flight feathers that exhibit no signs of molt. If the reproduction season and the months that followed were favorable for this year’s brood of new eagles, there should be nearly as many hatch-year birds as there are adults in an overall population.By November, second-year (Basic I) Bald Eagles are replacing many of their flight feathers and often show ragged trailing edges in the wings due to the retention of some of the well-worn and notably longer juvenile feathers. Varying amounts of white mottling are visible on the breast, belly, and underwing coverts. Due to mortality, there are usually fewer second-year Bald Eagles than there are hatch-year or adult birds.Another example of a second-year (Basic I) Bald Eagle.Third-year (Basic II) Bald Eagles show more yellow in the bill and an “osprey face”, a white head with a wide dark line through the eye. Most of the juvenile flight feathers have been replaced, so the wing edges appear more uniform. Like the second-year eagles, there is a varying amount of white in the breast, belly, and underwing coverts. In an overall population of eagles, birds in this age class are usually less common than those that are younger or those that are adults.Composite image of Bald Eagles in typical November plumage during their first three years. To see more images like this, be certain to click the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab at the top of this page.A fourth year (Basic III) Bald Eagle will often be seen with a black-bordered tail and a thin dark line through the eye. In some birds, traces of these traits can linger into the fifth year and beyond. These plumage types are usually the least frequently observed among an overall population of Bald Eagles. (Note: In these older birds, there develops significant variation in the timing of feather molt. In rare cases, fourth-year Bald Eagles may show minimal dark color in the tail or eye line and may appear to be in near definitive adult plumage.)A possible fifth-year (Basic IV) Bald Eagle.Adult Bald Eagles in definitive plumage. Birds in this plumage class are often the most frequently observed because the group includes all eagles five or six years of age and older.
While the Bald Eagles are still stealing the show, cold and gusty weather should bring an increasing number of Golden Eagles our way during the remainder of the month. Some are already trickling through…
This “before-third-year” Golden Eagle shows no visible signs of molt in its juvenile (hatch-year) plumage, but a look at the upperwing coverts is needed to properly age the bird. To learn more about the molt sequence in Golden Eagles, be sure to click the “Golden Eagle Aging Chart” tab at the top of this page.A “before-third-year” Golden Eagle (top) passing the lookout along with a second-year Bald Eagle (bottom).Another “before-third-year” Golden Eagle. More are on the way!
Later this month, Bald Eagle numbers on the lower Susquehanna below Conowingo Dam (U.S. 1) near Rising Sun, Maryland, will begin to grow. Fisherman’s Park, located along the west shoreline below the dam, is an excellent place to observe and photograph scores of these regal birds. And few places provide a better opportunity to learn to differentiate Bald Eagle age classes. If you’re really lucky, a Golden Eagle or two may drop in as well. So plan to make the trip. The best time to visit is on a weekday. The parking lot can become overcrowded on weekends and will be closed under such circumstances. It’s best to avoid the long Thanksgiving weekend as well.
It’s a hot summer weekend with a sun so bright that creosote is dripping from utility poles onto the sidewalks. Dodging these sticky little puddles of tar can cause one to reminisce about sultry days-gone-by.
Sometime in July or August each year, about half a century ago, we would cram all the gear for seven days of living into the car and head for the beaches of Delmarva or New Jersey. It was family vacation time, that one week a year when the working class fantasizes that they don’t have it so bad during the other fifty-one weeks of the year.
The trip to the coast from the Susquehanna valley was a day-long journey. Back then, four-lane highways were few beyond the cities of the northeast corridor and traffic jams stretched for miles. Cars frequently overheated and steam rolled from beneath the hoods of those stopped to cool down. There were even 55-gallon drums of non-potable water positioned at known choke points along some of the state roads so that motorists could top off their radiators and proceed on. Within these back-ups there were many Volkswagen Beetles pausing along the side of the road with the rear hood propped up. Their air-cooled engines would overheat on a hot day if the car wasn’t kept moving. But, despite the setbacks, all were motivated to continue. In time, with perseverance, the smell of saltmarsh air was soon rolling in the windows. Our destination was near.
At the shore, priority one was to spend plenty of time at the beach. Sunbathers lathered up with various concoctions of oils and moisturizers, including my personal favorite, cocoa butter, then they broiled themselves in the raging rays of the fusion-reaction furnace located just eight light-minutes away. Reflected from the white sand and ocean surf, the flaming orb’s blinding light did a thorough job of cooking all the thousands of oil-basted sun worshippers packing the tidal zone for miles and miles. You could smell the hot cocoa butter in the summer air as they burned. Well, maybe not, but you could smell something there.
By now, you’re probably saying, “Hey, why weren’t you idiots wearing protection from the sun’s harmful U.V. rays?”
Good question. Uncle Tyler Dyer reminds me that back in the sixties, a sunscreen was a shade hung to cover a window. He continued, “Man, the only sun block we had was a beach ball that happened to pass between us and the sun.”
A beach ball doesn’t cast much of a shadow. (NASA Solar Dynamics Observatory base image)
During several of our summertime beach visits in the early 1970s, we got a different sort of oil treatment—tar balls. We never noticed the things until we got out of the water. Playing around at the tide line and taking a tumble in the surf from time to time, we must have picked them up when we rolled in the sand.
Uncle Ty wasn’t happy, “Man, they’re sticking all over our legs and feet, and look at your swim trunks, they’re ruined. And look in the sand, they’re everywhere.” The event was one of the seeds that would in time grow into Uncle Ty’s fundamental distrust of corporate culture.
Looking around, tar balls were all over everyone who happened to be near the water. Rumor on the beach was that they came from ships that passed by offshore earlier in the day. The probable source was the many oil spills that had occurred in the Mid-Atlantic region in those years. During the first six months of 1973 alone, there were over 800 oil spills there. Three hundred of those spills occurred in the waters surrounding New York City. The largest, almost half a million gallons, occurred in New York Harbor when a cargo ship collided with the tanker “Esso Brussels”. Forty percent of that spill burned in the fire that followed the mishap, the remainder entered the environment.
When it was time to clean up, we slowly removed the tar from our legs and feet by rubbing it away with a rag soaked in charcoal lighter fluid or gasoline. Needless to say, our skin turned redder than it had already been from sunburn.
Letting swimmers and wildlife roll around in the sand is no longer the preferred method of cleaning up tar balls from man-made oil spills. Here, President Obama examines tar balls resulting from the April 20, 2010, B.P. Deepwater Horizon spill in the Gulf of Mexico. An organized cleanup effort followed this May 28, 2010, visit to the polluted Port Fourchon beach in Louisiana.
After a full day in the surf, we’d be on our way back to our “home base” for summer vacation, a campground nestled somewhere in the pines on the mainland side of the tidal marshes behind our beach’s barrier island. There, we’d shake the sand out of our trunks and savor the feeling of dry clothing. As the sun set, the smoke, flicker, and crackle of dozens of campfires filled the spaces between the tents and camping trailers. Colored lights strung around awnings dazzled sun-weary eyes as night descended across the landscape. We’d commence the process of incinerating some marshmallows soon after. Then, sometime while we were roasting our weenies and warming our buns, we’d hear it.
His device didn’t have a very good muffler. It sounded like a rusty old lawn mower running on the back of a rusty old truck that didn’t sound much better. And you could see the cloud rising above the campsites around the corner as he approached. It was the mosquito man, come to rid the place of pesky nocturnal biting insects. Behind him, always, were young boys on bicycles riding in and out of the fog of insecticide that rolled from the back of the truck.
Curious children seen following the mosquito man in a 1947 Universal Newsreel.
One was wise to quickly eat your campfire food and put the rest away before the fog rolled in. You had just minutes to choke down that burned up hot dog. Then the sense of urgency was gone. Everyone just sat around at picnic tables and on lawn chairs bathing in the airborne cloud. A thin layer of insecticide rubbed into the skin along with the liberal doses of Noxzema being applied to soothe sunburn pain will get you through the night just fine.
By the early 1970s, fogging of campgrounds to eliminate nuisance mosquitos was conducted using primarily the insecticide carbaryl (Sevin). Prior to that, in the years following World War II, DDT was the one-trick pony for killing everything everywhere. In 1947, the youth of San Antonio, Texas were subjected to repetitive direct spraying with DDT to eliminate the “germs” responsible for poliomyelitis. It was a misguided use of the pesticide. (Universal Newsreel image)Don’t you kids know that there’s sodium nitrite and saturated fat in those luncheon meats you’re eating? And the bread, aren’t you concerned about all that gluten? Oh, and by the way, they’re spraying you down with DDT again. It really happened in 1947 in San Antonio, Texas. (Universal Newsreel image)
Perhaps the most memorable event to occur during our summer vacations happened at the moment of this writing, fifty years ago.
We were vacationing in a campground in southern New Jersey. Our family and the family of my dad’s co-worker gathered in a mosquito-mesh tent surrounding a small black-and-white television. An extension cord was strung to a receptacle on a nearby post, and the cathode ray tube produced the familiar picture of glowing blue tones to illuminate the otherwise dark scene. There was constant experimentation with the whip antenna to try to get a visible signal. There were no local UHF broadcasters and the closest VHF television stations were in Philadelphia, so the picture constantly had “snow” diminishing its already poor clarity. But we could see it, and I’ll never forget it.
Neil Armstrong steps off the landing gear pad to be the first human to walk on the moon. July 20, 1969, 10:56 P.M. E.D.T. (NASA image)Armstrong left the field of view of the LEM-mounted camera for minutes at a time as he completed various tasks. TV viewers heard audio of his conversations with partner Edwin “Buzz” Aldrin and Houston Mission Control during these interludes. It was definitely not coverage designed for the short attention span of typical TV audiences. (NASA image)Edwin “Buzz” Aldrin descends the ladder on the LEM’s landing gear to reach the moon’s surface 19 minutes after Armstrong. (NASA image)Because NASA used a different video format than broadcast television, images seen at the time of the moon walk were of poor quality, produced by aiming a TV camera at a NASA monitor. Quality still images, including this one of Edwin “Buzz” Aldrin descending to the lunar surface, were available only after the astronauts returned exposed film to earth for processing. (NASA image by Neil Armstrong)Edwin “Buzz” Aldrin overlooking the LEM “Eagle” at Tranquility Base. (NASA image by Neil Armstrong)Neil Armstrong took this iconic image of Edwin “Buzz” Aldrin using a Hasselblad camera. His reflection can be seen in Aldrin’s visor. (NASA image by Neil Armstrong)Neil Armstrong (1930-2012), first man on the moon. (NASA image)
SOURCES
Andelman, David A. “Oil Spills Here Total 300 in ’73”. The New York Times. August 8, 1973. p.41.
Cortright, Edgar M. (Editor). 1975. Apollo Expeditions to the Moon. National Aeronautics and Space Administration. Washington, DC.
They can be a pesky nuisance. The annoying high-frequency buzzing is bad enough, but it’s the quiet ones that get you. While you were swatting at the noisy one, the silent gender sticks you and begins to feed. Maybe you know it, or maybe you don’t. She could make you itch and scratch. If she’s carrying a blood-borne pathogen, you could get sick and possibly die.
To humans, mosquitos are the most dangerous animal in the world (though not in the United States where man himself and the domestic dog are more of a threat). Globally, the Anopheles mosquitos that spread Malaria have been responsible for millions and millions of human deaths. Some areas of Africa are void of human habitation due to the prevalence of Malaria-spreading Anopheles mosquitos. In the northeastern United States, the Northern House Mosquito (Culex pipiens), as the carrier of West Nile Virus, is the species of greatest concern. Around human habitations, standing water in tires, gutters, and debris are favorite breeding areas. Dumping stagnant water helps prevent the rapid reproduction of this mosquito.
In recent years, the global distribution of these mosquito-borne illnesses has been one of man’s inadvertent accomplishments. An infected human is the source of pathogens which the feeding mosquito transmits to another unsuspecting victim. Infectious humans, traveling the globe, have spread some of these diseases to new areas or reintroduced them to sectors of the world where they were thought to have been eliminated. Additionally, where the specific mosquito carrier of a disease is absent, the mobility of man and his cargos has found a way to transport them there. Aedes aegypti, the “Yellow Fever Mosquito”, carrier of its namesake and the Zeka Virus, has found passage to much of the world including the southern United States. Unlike other species, Aedes aegypti dwells inside human habitations, thus transmitting disease rapidly from person to person. Another non-native species, the Asian Tiger Mosquito (Aedes albopictus), vector of Dengue Fever in the tropics, arrived in Houston in 1985 in shipments of used tires from Japan and in Los Angeles in 2001 in wet containers of “lucky bamboo” from Taiwan…some luck.
Asian Tiger Mosquito in action during the daylight hours, typical behavior of the genus. This species has been found in the area of Conewago Falls since at least 2013.
Poor mosquito, despite the death, suffering, and misery it has brought to Homo sapiens and other species around the planet, it will never be the most destructive animal on earth. You, my bloodthirsty friends, will place second at best. You see, mosquitos get no respect, even if they do create great wildlife sanctuaries by scaring people away.
The winner knows how to wipe out other species and environs not only to ensure its own survival, but, in many of its populations, to provide leisure, luxury, gluttony, and amusement. This species possesses the cognitive ability to think and reason. It can contemplate its own existence and the concepts of time. It is aware of its history, the present, and its future, though its optimism about the latter may be its greatest delusion. Despite possessing intellect and a capacity to empathize, it is devious, sinister, and selfish in its treatment of nearly every other living thing around it. Its numbers expand and its consumption increases. It travels the world carrying pest and disease to all its corners. It pollutes the water, land, and air. It has developed language, culture, and social hierarchies which create myths and superstitions to subdue the free will of its masses. Ignoring the gift of insight to evaluate the future, it continues to reproduce without regard for a means of sustenance. It is the ultimate organism, however, its numbers will overwhelm its resources. The crowning distinction will be the extinction.
Homo sapiens will be the first animal to cause a mass extinction of life on earth. The forces of nature and the cosmos need to wait their turn; man will take care of the species annihilation this time around. The plants, animals, and clean environment necessary for a prosperous healthy life will cease to exist. In the end, humans will degenerate, live in anguish, and leave no progeny. Fate will do to man what he has done to his co-inhabitants of the planet.
The Bald Eagle (Haliaeetus leucocephalus) is again a breeding species in the Susquehanna River watershed. It is generally believed that during the mid-twentieth century, Dichlorodiphenyltrichloroethane (DDT) pesticide residues accumulated in female top-of-the-food-chain birds including Bald Eagles. As a result, thinner egg shells were produced. These shells usually cracked during incubation, leading to failed reproduction in entire populations of birds, particularly those that fed upon fish or waterfowl. In much of the developed world, DDT was used liberally during the mid-twentieth century to combat Malaria by killing mosquitos. It was widely used throughout the United States as a general insecticide until it was banned here in 1972. (Editors Note: There is the possibility that polychlorinated biphenyls [P.C.B.s] and other industrial pollutants contributed to the reproductive failure of birds at the apex of aquatic food chains. Just prior to the recovery of these troubled species, passage of the Clean Water Act in 1972 initiated reductions in toxic discharges from point sources into streams, rivers, lakes, bays, and oceans. Production of P.C.B.s was banned in the United States in 1978. Today, P.C.B.s from former discharge and dumping sites continue to be found in water. Spills can still occur from sources including old electric transformers.)To substitute any other beast would be folly. Man, the human, Homo sapiens, the winner and champion, will repeatedly avail himself as the antagonist during our examination of the wonders of wildlife. He is the villain. The tragedy of his self-proclaimed dominion over the living things of the world will wash across these pages like muddy water topping a dam. There’s nothing I can do about it, aside from fabricating a bad novel with a fictional characterization of man. So let’s get on with it and take a look at “A Natural History of Conewago Falls”. Let’s discover the protagonist, the heroic underdog of our story, “Life in the Lower Susquehanna River Watershed.”
Over the top today.
SOURCES
Avery, Dennis T. 1995. Saving the Planet with Pesticides and Plastic: The Environmental Triumph of High-Yield Farming. Hudson Institute. Indianapolis, Indiana.
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Co. New York.
Newman, L.H. 1965. Man and Insects. The Natural History Press. Garden City, New York.
