Gray Tree Frogs: Garden Gate Icons and Keystone North American Species

Summary: Gray tree frogs are Garden Gate icons and keystone North American species through emergences every February or March in planned and wild amphibian gardens.

Gray tree frog is a New World native that is considered a keystone North American species; gray tree frog displays gray and green coloring in Missouri Ozarks: Bob Warrick, CC BY SA 4.0, via Wikimedia Commons

Gray tree frogs are Garden Gate icons featured in the magazine’s From the WILD SIDE department for the February 2015 issue and keystone North American species for planned and wild amphibian gardens.

Keystone species bear evidence of balanced, sustainable eco-systems by their presence in habitat niches and of imbalanced, stressed environments by their absence or by their scarcity. Gray tree frogs count among obligate, permanent, year-round residents of forested and wooded wetlands even though their incidence tends to be most observable during mating seasons. Master gardener and master naturalist wildlife mappers detect the earliest evidence of mating-driven gray tree frogs every February or March and the final indication every July.

Gray tree frogs escape detection in autumn and in winter when falling temperatures discourage mating-related advertisement, aggression and release calls and impel burrowing out of sight.

Planned and wild amphibian gardens fill habitat niches east of the Great Plains in Mexico and in the United States and of the Prairies in Canada. Alabama, Florida, Georgia, Mississippi and South Carolina generate no records of gray tree frog appearances despite representing part of the related Cope’s gray tree frog’s range.

Whatever forested or wooded field, garden, marsh, meadow, pasture, pool or swamp meets heat, humidity, light and moisture tolerances has chances of sustaining gray tree frogs.

Deciduous trees include American elm, black willow, box elder, Eastern cottonwood, pin oak, red maple, river birch, silver maple, speckled alder, white oak and yellow birch. Balsam fir and Canadian hemlock join other cone-bearing evergreens: Atlantic white cedar, black spruce, northern white cedar, pitch pine, red spruce, white pine and white spruce.

The underbrush knits deciduous understories of arrow-wood, buttonbush, highbush, sheepberry, smooth alder, summer-sweet, water-willow, winter-berry and witherod with evergreen understories of greenbrier, leatherleaf, male-berry and sheep-laurel.

The vegetative layers above the ground cover and beneath the understory let gray tree frogs access, predator-free, soil for burrowing tunnels and water for depositing eggs. They mix aquatic plants such as pondweeds and water lilies, carnivorous plants such as bladderworts and pitchers and flowering plants such as cardinal flowers and nettles.

Planned and wild amphibian gardens need ground-dwelling arthropod prey on blue-joint, bulrushes, bur-reeds, manna-grass, reed canary-grass, rushes and sedges and on cinnamon, marsh and sensitive ferns.

Layered landscapes offer gray tree frogs horizontal branches for sunning, nocturnal waters for breeding and egg-laying and transportation networks from predatory amphibians, fish, mammals and reptiles.

Tiger salamanders prey upon black-blotched, long-tailed, 1.97-inch (50-millimeter), red tadpoles hatched from 2,000 brown-white, four- to seven-day-old, vegetation-anchored, yolk-filled, 0.043- to 0.047-inch (1.1- to 1.2-millimeter) eggs.

Gray tree frogs quit tadpole stages in two months and bright green, 0.6-inch (15.24-millimeter) froglet stages in two years during expected seven- to nine-year life cycles. Variable 1.25- to 2.06-inch (3.18- to 5.23-centimeter) sizes reflect head-and-body lengths for brown-, gray-, green-blotched or bodied, orange-thighed, speckle-bellied, speckle-throated males and olive-gray, pale-bellied, pale-throated females. Bullfrogs, green frogs, opossums, raccoons, skunks and snakes stalk male gray tree frogs chirping at three- to four-second intervals and trilling 35 to 70 notes per second.

Planned and wild amphibian gardens tend to keep gray tree frogs busy breeding, chasing prey, escaping predators and hibernating in Canada, Mexico and the United States.

Gray tree frog casts a shadow on underside of leaf: Rick L. Hansen/US Fish and Wildlife Service-Midwest Region, Public Domain, via USFWS National Digital Library

Acknowledgment

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

Image credits:

gray tree frog, Missouri Ozarks: Bob Warrick, CC BY SA 4.0, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Gray_Tree_Frog,_Missouri_Ozarks.JPG

gray tree frog on leaf: Rick L. Hansen/US Fish and Wildlife Service-Midwest Region, Public Domain, via USFWS National Digital Library @ http://digitalmedia.fws.gov/cdm/singleitem/collection/natdiglib/id/11720/rec/4

For further information:

“Eastern Gray Treefrog.” BioKIDS > Critter Catalog > Frogs, Salamanders, and Caecilians > Tree Frogs.
Available @ http://www.biokids.umich.edu/critters/Hyla_versicolor/

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

“Gray Treefrog – Hyla versicolor.” Minnesota Department of Natural Resources > Nature > Animals > Reptiles / Amphibians > Frogs & Toads > Treefrogs.
Available @ http://www.dnr.state.mn.us/reptiles_amphibians/frogs_toads/treefrogs/gray.html

“Gray Treefrog – Hyla versicolor.” New Hampshire Public Television > NatureWorks.
Available @ http://www.nhptv.org/Natureworks/graytreefrog.htm

“Gray Treefrog (Hyla versicolor and H. chrysoscelis).” Michigan Department of Natural Resources > Wildlife & Habitat > Wildlife Species > Amphibians & Reptiles.
Available @ http://www.michigan.gov/dnr/0,4570,7-153-10370_12145_12201-60110--,00.html

IUCN SSC Amphibian Specialist Group. 2015. “Hyla versicolor.” The IUCN Red List of threatened Species 2015: e.T55687A78905520. dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T55687A78905520.en.
Available @ http://www.iucnredlist.org/details/55687/0