A Natural History of Conewago Falls—The Waters of Three Mile Island
Amphibians
AMPHIBIANS
of the Lower Susquehanna River Watershed
With (forthcoming) commentary on the species including notes from the historic writings of nineteenth-century geologist, naturalist, and philologist Professor Samuel Steman Haldeman and Linnaean Society of Lancaster City and County naturalist Jacob Stauffer.
Samuel Steman Haldeman was born in 1812 at the Haldeman Mansion along the Susquehanna River at Locust Grove near Bainbridge in Lancaster County, Pennsylvania. The mansion can be seen from the Northwest Lancaster County River Trail and is open for tours during scheduled events. See the Haldeman Mansion Preservation Society website for more information.In the vicinity of his boyhood home at the mouth of Conoy Creek, Haldeman explored the waters and shores of the Susquehanna below Conewago Falls. He developed an interest in the animal bones he found and began assembling skeletons. Haldeman collected the shells of the mollusks occurring there, a long-term pursuit that eventually led to the writing and publishing of “A Monograph of the Freshwater Univalve Mollusks of the United States” and “On the Freshwater Mollusca Common to Europe and America, Including Theoretical Observations Upon the Species and Their Distribution”. The former was the country’s first comprehensive account of its freshwater snails. Charles Darwin would comment on the latter in “The Origin of Species” as part of the book’s appendix, “…An Historical Sketch of the Progress of Opinion on the Origin of Species”.During his adult years, Samuel Steman Haldeman resided along the Susquehanna at Chickies Rock near Marietta, Pennsylvania. He died at his home there in 1880. Haldeman left behind a wide-ranging body of work in the fields of geology, zoology, linguistics, and archaeology. Among these are commentary on the animals, including amphibians, found in Lancaster County during the early 1800s. His use of binomial nomenclature relieves us of the uncertainty that comes with interpreting similar lists of wildlife that use colloquial names. His sketch is the foundation of this list. (Mathew Brady image-Library of Congress)
SPECIES STATUS KEY
extinct-a native species no longer existing or living.
extirpated-a native species no longer occurring in the wild in the Lower Susquehanna River Watershed.
exotic-a free-ranging escaped or released non-native species or variety; most are unwanted pets, domesticated farm animals, or zoo specimens.
introduced-a non-native species released into the wild, including amphibians stocked to create temporary populations as well as those that establish self-sustaining breeding populations—often at the expense of one or more native species.
Federally Endangered-a native species listed by the United States government as imminently in danger of extinction.
PA Endangered-a native species listed by the Commonwealth of Pennsylvania as imminently in danger of extinction or of extirpation as a breeding species in the state.
MD Endangered-a native species listed by the State of Maryland as imminently in danger of extinction or of extirpation as a breeding species in the state.
Federally Threatened-a native species listed by the United States government as under threat to become an endangered species in the foreseeable future.
PA Threatened–a native species listed by the Commonwealth of Pennsylvania as under threat to become an endangered species in the state in the foreseeable future.
MD Threatened-a native species listed by the State of Maryland as under threat to become an endangered species in the state in the foreseeable future.
PA Candidate-an uncommon native species that could, in the future, become listed by the Commonwealth of Pennsylvania as endangered or threatened in the state.
A LIST OF THE AMPHIBIANS
of the Lower Susquehanna River Watershed
Classified using traditional taxonomic ranks and selected cladistic groups.
Domain-Eukaryota
Kingdom-Animalia
Phylum-Chordata
Subphylum-Vertebrata
Superclass-Osteichthyes/Clade-Euteleostomi:
The “bony vertebrates” including the Actinopterygians, the ray-finned fishes, and the Sarcopterygians, the lobe-finned fishes and tetrapods.
Clade-Sarcopterygii:
The lobe-finned fishes and tetrapods. All members of the clade Sarcopterygii presently occurring in the Susquehanna watershed (amphibians, reptiles, birds, and mammals including humans) are tetrapod descendants of extinct lobe-finned fishes.
Superclass-Tetrapoda:
The animals, living and extinct, that descended from fishes beginning in the Late Devonian epoch (about 370 million years ago), most having four limbs—the amphibians, the reptiles (including snakes, pterosaurs, dinosaurs, and birds), and the mammals.
Clade-Batrachomorpha:
The group of living and extinct tetrapods having more similarity to modern amphibians (Lissamphibia) than to the Reptiliomorpha (the clade including the amniotes—reptiles, pterosaurs, dinosaurs, birds, and mammals).
Eggs of the Green Frog. Unlike the amniotic Reptiliomorpha, most modern amphibians (Lissamphibia) deposit their eggs in water, making them very susceptible to the effects of pesticides, pollution, and habitat loss and degradation. Interference with their multi-stage life cycle and alteration of their essential ecosystems has led to amphibians being ranked as the world’s most imperiled group of tetrapods. Populations of many amphibians have become fragmented and isolated from others of their kind, making numerous species vulnerable to piecemeal elimination. Man has not been a friend to the planet’s amphibians.The final step of a Green Frog’s metamorphosis from its aquatic larval stage to an air-breathing semi-terrestrial adult. This step includes the growth of four limbs for locomotion, an attribute typical of most tetrapods.
Class-Amphibia
Order-Temnospondyli: an order(?) of extinct(?) early amphibians of the mid-Carboniferous Period through the Early Cretaceous epoch—about 330 to 120 million years ago. Continuing research suggests that some Temnospondyli amphibians are ancestral to modern amphibians (Lissamphibia).
Family-Metoposauridae: an extinct family of large Triassic amphibians.
A fossilized skull of Anaschisma browni (Koskinonodon/Buettneria perfectus) found just west of the Susquehanna in rocks of the New Oxford Formation at Zion’s View in York County, PA. About 230 to 220 million years ago, during the Late Triassic Period, this large salamander-like amphibian, which sometimes achieved lengths of five feet or more, lurked in the wooded swamps of the subsiding Gettysburg Basin. It possessed needle-like teeth and probably fed predominately on fish. (Specimen: State Museum of Pennsylvania, Harrisburg)
The Hellbender (Cryptobranchus alleganiensis), a species of cool, rocky, fast-moving, well-oxygenated streams, has been extirpated from the main stem of the lower Susquehanna. It was most recently reported prior to 2000 in river tributaries in Dauphin and Perry Counties. The dominant factors contributing to the species’ disappearance from the lower Susquehanna likely include: the introduction of non-native predatory fish species, water pollution, eutrophication, and silt deposition behind dams. (United States Fish and Wildlife Service image by Gary Peeples)
Family-Salamandridae
Notophthalmus viridescens (Eastern Newt)
The “Red Eft” is the terrestrial sub-adult stage of the Eastern Newt (Notophthalmus viridescens).Soon after transforming from an aquatic larval stage, young “Red Efts” disperse into forests, often traveling far from their places of birth. This tiny individual was found on the crest of a ridge hundreds of feet above, and more than a half a mile from, the nearest body of water.An Eastern Newt (Notophthalmus viridescens) beginning transformation from the terrestrial “Red Eft” sub-adult stage to the aquatic adult stage. This individual was found during March in the company of breeding Wood Frogs (Lithobates sylvaticus) in the water-starved bed of a vernal pond.The aquatic adult stage of the Eastern Newt (Notophthalmus viridescens) in a beaver (Castor canadensis) pond. (Vintage 35 mm image)
Northern Dusky Salamander (Desmognathus fuscus). (Shannon Wallace image of Owen Melbert specimen)Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus). (Ohio Department of Natural Resources image)A Red-backed Salamander (Plethodon cinereus).A Red-backed Salamander (Plethodon cinereus) in the “lead-backed” color variation.Northern Slimy Salamander (Plethodon glutinosus).The Northern Two-lined Salamander (Eurycea bislineata) is a denizen of clear rocky streams with pebble and sand substrates.Long-tailed Salamander (Eurycea longicauda). (United States Fish and Wildlife Service image by Ryan Hagerty)Spring Salamander (Gyrinophylus porphyriticus). (United States Department of Agriculture image by John D. Wilson)An adult Red Salamander (Pseudotriton ruber). (United States Geological Survey image by Lindsey Perkurny)An aquatic stage Red Salamander (Pseudotriton ruber), nearing completion of a multi-year transformation to adulthood, finds refuge in a clear cool headwaters spring seep within its forest habitat.Red Salamander (Pseudotriton ruber). (United States Geological Survey image by Lindsey Perkurny)Four-toed Salamander (Hemidactylium scutatum). (United States Geological Survey image by Lindsey Perkurny)
Family-Ambystomatidae
Ambystoma jeffersonianum (Jefferson Salamander)
Ambystoma maculatum (Spotted Salamander)
Ambystoma opacum (Marbled Salamander)
Jefferson Salamander (Ambystoma jeffersonianum). (United States Department of Agriculture image)Spotted Salamander (Ambystoma maculatum) in a vernal pool. (Vintage 35 mm image)Spotted Salamander (Ambystoma maculatum) in a vernal pool. (Vintage 35 mm image)Marbled Salamander (Ambystoma opacum). (National Park Service image)Marbled Salamander (Ambystoma opacum) larva in a vernal pool.
The Eastern Spadefoot (Scaphiopus holbrookii) breeds in unpolluted, usually seasonal, wetlands. By necessity, this site is not far from the sandy terrain where it lives in self-dug burrows for the balance of the year. Its range in the Susquehanna basin has been severely fragmented. The species is probably close to being extirpated in the Lower Susquehanna River Watershed. (National Park Service image)
Family-Bufonidae
Anaxyrus americanus (American Toad)
Anaxyrus fowleri (Fowler’s Toad)
The American Toad (Anaxyrus americanus) is common near the undisturbed pollution-free fish-free vernal pools where it breeds during March and April.American Toad (Anaxyrus americanus) tadpoles in a vernal pool.Fowler’s Toad (Anaxyrus fowleri).Fowler’s Toads (Anaxyrus fowleri) breed in late May and June in temporary pools of water, often in streamside meadows, as seen here, or in other riparian wetlands. They are not nearly as widespread as the American Toad in the Lower Susquehanna River Watershed.
Family-Hylidae
Hyla chrysoscelis (Cope’s Gray Tree Frog)
Hyla versicolor (Gray Tree Frog)
Pseudacris crucifer (Spring Peeper)
Pseudacris feriarum (Upland Chorus Frog)
Acris crepitans (Cricket Frog)-extirpated? PA Endangered
Gray Tree Frog (Hyla versicolor). (United States Fish and Wildlife Service image by Zachary Cava)The Spring Peeper (Pseudacris crucifer) is recognized by the dark “X” across its back.Spring Peepers (Pseudacris crucifer) mating in a vernal wetland.Upland Chorus Frog (Pseudacris feriarum). (National Park Service image)Cricket Frog (Acris crepitans). (United States Fish and Wildlife Service image by Sara Hollerich)
Family-Ranidae
Lithobates catesbeianus (American Bullfrog)
Lithobates clamitans (Green Frog)
Lithobates palustris (Pickerel Frog)
Lithobates pipiens (Northern Leopard Frog)
Lithobates sylvaticus (Wood Frog)
American Bullfrog (Lithobates catesbeianus) populations in the lower Susquehanna basin have been supplemented by introductions of adults and tadpoles, possibly to the detriment of smaller species of amphibians.Male (left) and female (right) American Bullfrogs (Lithobates catesbeianus).A mating pair of Green Frogs (Lithobates clamitans). Note the presence of dorsolateral ridges extending from the eye toward the posterior of the frog. These ridges are absent on otherwise similar American Bullfrogs (Lithobates catesbeianus).Green Frogs (Lithobates clamitans) will take advantage of nearly any vegetated body of clean fish-free water for breeding. This pair is using an urn-shaped patio planter converted to a water garden as its chosen site.Pickerel Frog (Lithobates palustris).The Northern Leopard Frog (Lithobates pipiens) can be common in high-quality riparian wetlands along the lower Susquehanna.Wood Frogs (Lithobates sylvaticus) spend the majority of their lives in damp forests, unnoticed by people. In the lower Susquehanna valley, they emerge from hiding places on a warm rainy night in March to journey to a nearby vernal pond where they begin calling still more Wood Frogs to their breeding site.Attracted by the calls of quacking males, an egg-laden female Wood Frog (Lithobates sylvaticus) visits an ephemeral wetland to breed.A mating pair of Wood Frogs (Lithobates sylvaticus).Wood Frog eggs must hatch and tadpoles must transform into terrestrial frogs before the vernal pond dries up in the summertime heat.Springtime Fairy Shrimp (Eubranchipus vernalis) and Wood Frog eggs with developing embryos in a vernal pool.A Wood Frog (Lithobates sylvaticus) tadpole in a vernal pond in early May.
SOURCES
Crother, Brian I. (Chair) Committee on Standard English and Scientific Names. 2017. “Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding”. Eighth Edition. Society for the Study of Amphibians and Reptiles Herpetological Circular No. 43. Shoreview, MN. pp. 1-102.
Haldeman, Samuel Steman. 1844. “Natural History of Lancaster County: Amphibia”. I. Daniel Rupp’s History of Lancaster County. Gilbert Hills. Lancaster, PA. p.472.
Maryland Natural Heritage Program. 2016. List of Rare, Threatened, and Endangered Animals of Maryland. Maryland Department of Natural Resources, 58 Taylor Avenue, Annapolis, MD 21401.
Pennsylvania Natural Heritage Program. PNHP Species Lists. www.naturalheritage.state.pa.us/Species.aspx Accessed August 14, 2019.
Shaffer, Larry L. 1991. Pennsylvania Amphibians and Reptiles. Pennsylvania Fish and Boat Commission. Harrisburg, PA.
Sigurdsen, T., and Bolt, J. R. 2010. “The Lower Permian Amphibamid Doleserpeton (Temnospondyli: Dissorophoidea), the Interrelationships of Amphibamids, and the Origin of Modern Amphibians”. Journal of Vertebrate Paleontology. 30:5. pp. 1360-1377.
Species Accounts—Pennsylvania Amphibian and Reptile Survey. Website: https://paherpsurvey.org/species.php Accessed 29 July, 2019.
Stauffer, Jacob. 1869. “Herpetology: Class of Reptiles”. J. I. Mombert’s An Authentic History of Lancaster County. J. E. Barr and Company. Lancaster, PA. pp.574-576.
