Eastern Spadefoots: Hourglass-Marked Back, Vertical Pupils

Summary: North American eastern spadefoot habitats get hourglass-marked backs, pale-marked sides and bellies, vertical pupils and hindlegs with sickled spades.

Dorsal (upper surface) view shows hourglass pattern on eastern spadefoot toad (Scaphiopus holbrookii) in Florida Panhandle, northwestern Florida: Brad Michael "Bones" Glorioso/USGS Wetland and Aquatic Research Center (formerly National Wetlands Research Center), Public Domain, via USGS Amphibian Research and Monitoring Initiative (ARMI)

North American eastern spadefoot habitats achieve distribution ranges from Massachusetts, Connecticut, Rhode Island and New York through New Jersey, Florida, Louisiana, Arkansas, Missouri, Illinois, Indiana, Ohio, West Virginia, Pennsylvania and everywhere in-between.

Eastern spadefoots bear their common name for skin color and daytime and non-breeding season living quarters and cowbell or rain frogs for biogeographies east of the Mississippi River and for burrowing backward with sand-digging, soil-digging spade-shaped tubercles (bumps) on both hind feet. The scientific name Scaphiopus holbrookii commemorates John Edwards Holbrook (Dec. 31, 1796-Sep. 8, 1871). Scientific designations delve into descriptions in 1835 by Richard Harland (Sep. 9, 1796-Sep. 30, 1843).

Eastern spadefoot life cycles expect dry forests, pinewoods and pine-oak woods with shallow, temporary ditches, ponds and pools and with heavy rainfall and sandy, well-drained soils.

March through September furnish eastern spadefoot life cycles with breeding season months despite predatory.

Slim-waisted green treefrogs go on large sticky toe pads and long legs from bushes, shrubs and trees to breeding bayous, ditches, lakes, ponds, pools and swamps. Matched filtering helps them hear, despite mixed-species choruses, by calls having frequency ranges that vibrate two circular tympanic-membraned eardrums and the inner-ear's amphibian and basilar papillae. Closed-mouth, closed-nostril advertisement, similar courtship and rain, aggression and similar release calls involve lung expirations that impel air streams over vocal cords and inflate vocal sacs.

Batrachochytrium dendrobatidis fungal disease, fertilizer runoff, globally warmed climate change, nonnative species, toxic pesticides, trematode fluke-induced deformities and ultraviolet radiation jeopardize North American eastern spadefoot habitats.

Three hundred to 4,000-egg clusters and, four to 14 days later, gill-breathing, keel-tailed tadpoles keep to water whereas legged, lung-breathing, tailless adults know land and water.

Green treefrogs look like 4.5- to 5.5-millimeter (0.17- to 0.22-inch), herbivorous (plant-eating) fish and like little-legged, long-tailed, 2.36-plus-inch (60-plus-millimeter) carnivores (flesh-eaters) 25 to 45 days later. The male manages axillary amplexus (armpit embrace) by maintaining forelimbs behind his mate's front legs while mounted on her back to fertilize dark, sticky eggs externally. Tadpoles need algae, organic debris, plant tissue and suspended matter even though beetles, caterpillars, crickets, flies, mosquitoes, moths, pillbugs, sowbugs, spiders, stinkbugs and worms nourish adults.

North American eastern spadefoot habitats offer season's coldest temperatures, northward to southward, from minus 15 to 35 degrees Fahrenheit (minus 26.11 to 1.66 degrees Celsius).

Artificial and natural ditches, lakes, marshes, ponds, sloughs and swamps with bay laurel-dominant, cypress-dominated emergent, floating, submerged, waterside grassy, herbaceous, weedy, woody plants promote green treefrogs.

Lang Elliott, Carl Gerhardt and Carlos Davidson quantify 1.75- to 2.875-inch (4.44- to 7.30-centimeter) snout-vent (excrementary opening) lengths in The Frogs and Toads of North America. Adults reveal vertical pupils, yellow hourglass-patterned black-brown backs, small orange or pink tubercles (bumps) and blotched, yellow-spotted sides, flat foreheads and elongated sometimes curved black spades. Half-shut eyes show nictitating membranes (inner eyelids) and heads slant backward and upward while down-slurred explosive nasal errrrrrra! advertisement calls sound every five to 10 seconds.

North American eastern spadefoot habitats transmit choking croaks from large vocal pouches on explosive breeders with flat foreheads, vertical pupils, orange-pink bumps, yellow-marked sides and yellow hourglass-patterned black-brown backs.

eastern spadefoot toad (Scaphiopus holbrookii) under synonym Scaphiopus solitarius; illustration by Italian-born scientific illustrator J. Sera, lithograph by George Lehman/Lehman & Duval Lithographers; J.E. Holbrook's North American Herpetology (1836), vol. I, Plate XI, opposite page 83: Public Domain via Biodiversity Heritage Library

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Dorsal (upper surface) view shows hourglass pattern on eastern spadefoot toad (Scaphiopus holbrookii) in Florida Panhandle, northwestern Florida: Brad Michael "Bones" Glorioso/USGS Wetland and Aquatic Research Center (formerly National Wetlands Research Center), Public Domain, via USGS Amphibian Research and Monitoring Initiative (ARMI) @ https://armi.usgs.gov/gallery/result.php?search=Scaphiopus+holbrookii

eastern spadefoot toad (Scaphiopus holbrookii) under synonym Scaphiopus solitarius; illustration by Italian-born scientific illustrator J. Sera, lithograph by George Lehman/Lehman & Duval Lithographers; J.E. Holbrook's North American Herpetology (1836), vol. I, Plate XI, opposite page 83: Public Domain via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/35765112

For further information:

Elliott, Lang; Carl Gerhardt; and Carlos Davidson. 2009. The Frogs and Toads of North America: A Comprehensive Guide to Their Identification, Behavior and Calls. Boston MA; New York NY: Houghton Mifflin Harcourt.

Frost, Darrel. "Scaphiopus holbrookii (Harlan, 1835)." American Museum of Natural History > Our Research > Vertebrate Zoology > Herpetology > Amphibian Species of the World Database.
Available @ http://research.amnh.org/vz/herpetology/amphibia/index.php//Amphibia/Anura/Scaphiopodidae/Scaphiopus/Scaphiopus-holbrookii

Harlan, R. (Richard). 1835. "Genera of North American Reptilia, and a Synopsis of the Species: Rana Holbrookii." Medical and Physical Researches; Or, Original Memoirs in Medicine, Surgery, Physiology, Geology, Zoology, and Comparative Anatomy: 105-106. Philadelphia PA: Lydia R. Bailey Publ., Philadelphia, 214. 228.
Available via Internet Archive @ https://archive.org/stream/b21934605#page/105/mode/1up

Holbrook, John Edwards, M.D. 1836. "Scaphiopus solitarius." North American Herpetology; Or, A Description of the Reptiles Inhabiting the United States. Vol. I: 85-87. Philadelphia PA: J. Dobson.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/35765112

"The 2012 USDA Plant Hardiness Zone Map." The National Gardening Association > Gardening Tools > Learning Library USDA Hardiness Zone > USDA Plant Hardiness Zone Map.
Available @ https://garden.org/nga/zipzone/2012/